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THE NEW GEOGRAPHY DICTIONARYKEY GEOGRAPHICAL TERMS FOR THE 21ST CENTURY

J e f f H a r t e

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2 The New Geography Dictionary

Copyright © 2003 Geography Teachers� Association of New SouthWales Inc. All rights reserved. No reproduction, copy or transmission ofthis publication may be made without written permission

No paragraph or section of this publication may be reproduced, copiedor transmitted save with written permission or in accordance with theprovisions of the Copyright Act of 1996 (as amended)

Copying for educational purposes

Where copies of part or whole of this book are made under Part VB ofthe Copyright Act, the law requires that prescribed procedures befollowed. For information, contact the Copyright Agency Limited.

Acknowledgments

The author and publisher wish to thank

� Nyree Malone for carefully crafting all diagrams and line drawings

� Nick Hutchinson, President of the Geography Teachers� Associationof New South Wales, for his initial and ongoing support of thisproject as well as Geoff Paterson for his meticulous editing

� Figure 62 � reproduced with permission Geoscience Australia

� Figures 63, 67 and 69 � source ©Land and Property Information,Panorama Avenue, Bathurst 2795 www.lpi.nsw.gov.au

� Figure 64 � reproduced with permission of the Department ofDefence, Australia

� Figure 65b � reproduced with permission Geography Teachers�Association of NSW (P Skinner and A Mahler)

� Figure 68 � base map reproduced with permission of TASMAP

* * *Every effort has been made to trace and acknowledge copyrightmaterial. The author and publisher would welcome any informationfrom people who believe they own copyright to material in thisdictionary.

Additional copies of this dictionary can be obtained by contacting:

GTANSW c/- Gladesville Public SchoolPO Box 602Gladesville NSW 1675

National Library of Australia Cataloguing-in-Publication data

The New Geography Dictionary � Key Geographical Terms for the 21st Century ISBN 0 9751105 0 0

1. Geography Dictionary 2. Key Terms in Geography

Cover, text layout, design and typesetting by: Imagine Success, Paradise Point, Queensland 4216 � [email protected]

Printed by: Fergies the Printers, Brisbane

Published by: Geography Teachers� Association of New South Wales Inc.

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The New Geography Dictionary 3

PREFACEAuthor’s Note

Initially conceived as a much smaller project, this Dictionary is the result of aperceived need for Geography students to improve their use of appropriateGeographic terminology, their comprehension, and overall Geographic literacy.

There is a variety of excellent Geography textbooks for students, many of whichprovide key-word glossaries. There is, however, no central source for students toaccess the necessary terminology.

As a result, a much larger volume has evolved. The key terms included here, andnecessary to succeed in Geography, address the themes of ‘environments’,‘communities’ and ‘changing environments and communities’. Within these themesa major focus has been given to terms relating to the atmosphere, lithosphere,hydrosphere, biosphere and the human environment.

Although there is a range of dictionaries available to students, there is no dictionarythat currently meets the needs of Australia’s young Geographers. There aredictionaries on areas such as ‘the environment’, ‘the ecosystem’, ‘Human Geography’and ‘Physical Geography’ – but none that address the vocabulary needed to succeedin the learning sphere of most concern to students.

Students need to grapple with the intricacies of the biophysical environment,population and settlement, development, globalisation and even geopolitics asstipulated by the various syllabuses throughout Australia and around the world.

The entries in The New Geography Dictionary are necessarily brief but they can beenhanced with reference to supporting italicised terms. Sufficient detail is provided tomeet the needs of most Geography students. A variety of approaches has beenincluded beyond straight definitions – these include tabular summaries such as in‘contemporary geographic issues’ and the ‘geologic timescale’, illustrative summariessuch as in coastal terrains and the general circulation of the atmosphere, as well astables, photographs and graphs.

Many entries make reference to illustrative material. This material has been includedbecause the author acknowledge that students absorb and comprehend material indifferent ways. Sketch-diagrams, tables and photographs add to an enhancedunderstanding of the terms addressed. Some this illustrative material is provided infull colour. These items are referred to in the text and can be located in the full coloursections of this dictionary.

Students using this Dictionary will find the key terms are highlighted in bold followedby a concise definition. Many definitions include specialist terms and have their ownfamily of related concepts. For example, the ‘family’ of terms associated with ‘dune’include: seif dune, barchan dune, frontal dunes, and foredunes.

Readers are referred elsewhere in the Dictionary for an explanation of these relatedterms with the term italicised. Also included at the end of this Dictionary are somestandard abbreviations, prefixes and conversions that students will find useful.

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‘Populations of all countries of the world’ are also included with comparisons madebetween 1999 figures and projected 2050 figures.

While the terms included in this Dictionary are those most Geography students willencounter in their studies they are by no means exhaustive. For more detailedexplanations and a broader, academic, treatment of Geographic terminology readersare referred to M. Allaby’s Dictionary of the Environment, A. Goudie’s EncyclopedicDictionary of Physical Geography and R. Johnston’s Encyclopedic Dictionary ofHuman Geography.

Syllabuses throughout Australia are increasingly focusing on not only developing keycompetencies (skills), but also providing students with the opportunities to applythese skills. Not just map, graph and statistical skills but also skills that developeffective communication – both oral and written. These include encouraging andenhancing students’ literacy skills.

In this way students can be more effective agents of change, and contribute positivelyto community understanding. This relevant and up-to-date dictionary providesstudents with the necessary tools to be effective Geographers and to betterunderstand and participate in the world around them.

Improving literacy is increasingly a driving force in education today. Being familiarwith subject-specific terminology and using it correctly and in the right context is amajor challenge for today’s students. It is hoped that this Dictionary will go some wayin meeting this challenge.

Jeff HarteMoriah College, 2002

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1 Adiabatic lapse rates2 The vertical structure of the

atmosphere3 Banksia serrata4 Stages in the development of

successive parallel dunes5 Beaufort scale6 Bedding planes and vertical joints7 Biological Oxygen Demand for

various organic pollutants8 Looking up to the canopy9 The carbon cycle

10 The four, eight and sixteen pointcompass

11 Inland and coastal catchment areas12 Techniques for determining climate

change13 Common types of clouds14 A coastal terrain15 A woodland � a type of vegetation

community16 Contemporary geographic issues17 Plate tectonics and continental drift18 Examples of correlation19 The Nile delta20 An arid terrain21 A dissected plateau � the Shoalhaven

River,22 Examples of drainage patterns23 El Niño / Southern Oscillation (the

ENSO cycle)24 Faecal coliform counts for selected

rivers and lakes25 A fluvial terrain26 The general circulation of the

atmosphere27 Geologic time scale28 A glacial terrain29 A snow covered glacial valley30 The greenhouse effect31 Honeycomb weathering32 The hydrologic cycle33 Interlocking spurs34 The distribution of island-arcs in the

Pacific Basin and a cross sectionacross an island-arc

35 Kata Tjuta36 Climate and lake levels at Willandra

Lakes, New South Wales37 Latitude and longitude38 Lianas in a rainforest 39 Cross section (A) and a plan view (B)

of the Lake Mungo Lunette, WillandraLakes, NSW, Aust.

40 Map references41 Misfit streams42 The monsoon43 Open-cut mining in Western Australia44 The Pacific Ring of Fire � the

distribution of earthquakes andvolcanoes

45 Petroglyph46 The Phosphorus Cycle: flows between

sources and sinks, Australia-wide47 Pleistocene sea level changes48 World population growth49 Examples of population pyramids50 Types of precipitation � orographic,

frontal and convectional rainfall51 Types of shore platforms52 A shore platform53 A soil profile54 A speleothem � a limestone column55 Example of a synoptic chart56 The tombolo of Palm Beach, NSW57 Examples of urban hierarchies58 Urban models of the internal structure

of cities59 The von Thünen landuse model60 A wetland61 A zetaform beach62 Satellite Image � Cairns, Qld63 Vertical aerial photograph � Port

Kembla, NSW64 Topographic map � Jim Jim Creek,

Northern Territory.65 a) Ground-level photograph, The

Pinnacles, W.A. b) oblique aerialphotograph, Barrenjoey Headland,NSW

66 Satellite image � Sydney, NSW67 Vertical aerial photograph � Coffs

Harbour, NSW68 Topographic map � Mersey, Tasmania69 Orthophotomap � Morpeth, NSW

LIST OF FIGURES

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< less than> greater than= equal to% percent∞ infinityasl. above sealevelAPEC Asia Pacific Economic

CooperationBOD Biological Oxygen DemandBP Before PresentCBD Central Business DistrictCFC chlorofluorocarbonCGI contemporary geographic issuecm centimetreCSIRO Commonwealth Scientific and

Industrial ResearchOrganisationDO Dissolved Oxygeneg for exampleELR environmental lapse rateENE east north eastENSO El Nino Southern OscillationESE east southeastGDP Gross Domestic ProductGL gigalitregm gramsGPS Global Positioning SystemhPa hectopascalHYV high yielding varietyie that isIs. Isle (island)IPCC Intergovernmental Panel on

Climate Change kg kilogramkl kilolitrekm kilometrekm2 square kilometrekm3 cubic kilometre

Lat. latitudeLong. longitudeL litrem metresm2 square metrem3 cubic metremg milligrams ML megalitremm millimetresMt mountmya million years agoNGO non-government organisationNNE north northeastNNW north northwestOPEC Organisation of Petroleum

Exporting Countriespop. populationR. riversq. km square kilometresq. m square metreSSE south southeastSSW south southwestSW southwestUN United NationsUNCED United Nations Conference on

Environment and DevelopmentUNESCO United Nations Educational,

Scientific and CulturalOrganisation

UNEP United Nations EnvironmentProgram

UNHCR United Nations HighCommission for Refugees

USSR (former) Union of SovietSocialist Republics

WNW west northwestWSW west southwestWTO World Trade Organisation

ABBREVIATIONS USED

(Figure 26 ) figure directly related to this entry(see figure 26 ) figure includes this entry

(figure 26 colour) figure in colour section

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aa — a blocky, angularform of lava flow

abiotic — a term used torefer to those non-livingparts of the biophysicalenvironment (see bioticand ecosystem)

ablation — the removal of the surfacelayer of ice due to melting andevaporation. It also refers to theremoval of loose material from theland by wind (see deflation)

aborigine — an indigenous person of anarea eg the Inuit in Alaska andnorthern Canada; the Koori in Australia

abrasion — the wearing down orwearing away by friction. The rubbingof particles on the Earth’s surface,when transported by water or wind,wears away or abrades the surface thatthese particles come into contact with– such as a sea cliff

absolute humidity — the actualamount of water in the air usuallyexpressed as grams (of water) percubic metre (of air)

absolute location — the specificlocation of a point such as its latitudeand longitude, grid reference or areareference (see relative location)

absolute zero — theoretically the lowesttemperature that can be achieved; thatis 0ºK (Kelvin) or -273ºC. Absolutezero indicates the absence of heat andby definition all motion

abyssal plain — the flat, sedimentcovered, sea floor at depths of up to 2–3 kilometres

acacia — a type (genus) of tree found indrier subtropical and temperate areas.Acacias are common in Australia in thedrier interior of the continent but alsoin more moist areas where driermicroclimates are common such as the

dry exposed areas of plateaus. Acaciasare more widely known as Wattles

accelerated soil erosion — erosion,beyond that of natural erosion, causedby the activities of people (eg gullyerosion, sheet erosion)

acclimatisation — adaption by thebody to different climatic conditionssuch as high and low temperaturesand high altitude

acculturation — the process in whichimmigrants/indigenous people adoptsome of the cultural traits of thedominant culture

accumulation — the main aim ofcapitalism, where capital isreproduced in a ever increasing circlethrough reinvestment of surplus valueor profit

acidic rock — an igneous rockcontaining more than 10% quartz

acidity — a term to describe the pH of a soil or water; a pH below 7.2indicates acidic conditions (see acidsoil and pH)

acid rain — rainfall with a pH of lessthan 5.6. This is the pH level inprecipitation under natural conditions. Acid rain, or acid precipitation, occursas a result of the addition of particularchemicals into the atmosphere, suchas sulphur and nitrogen oxides. These chemicals are released into theatmosphere as a result of the burningand combustion of fossil fuels. Mixedwith water vapour in the atmosphereweak sulphuric and nitric acids areproduced with precipitation thenhaving a pH below 5.6. The significance of this is that waterreceived on Earth, such as in lakes, isharmful to fish. Received on land acid rain affects the

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ability of plants to photosynthesise. Also the weak acid attacks anddissolves any carbonate cements usedin building construction (see carbon-ation)

acid soil — a soil that has a pH below 7.2acid sulphate soils — soils rich in acid

sulphide found in tropical andsubtropical regions. They are relativelystable under a cover of water but thesulphide forms sulphate and sulphuricacid when they are drained

adiabatic — a term used to describe theprocess where a parcel of air rises,heats up or cools with no gain or lossof heat to the surrounding atmos-phere (see adiabatic lapse rate)

adiabatic lapse rate — the change intemperature with height as a parcel ofair is forced to rise (Figure 1). Whenair is forced to rise by convection,frontal uplift or by orographic upliftthe air rises into an area of lowerpressure. The air then expands. As itexpands the heat energy within it hasto heat a larger volume. So the overalltemperature falls. This is adiabaticcooling. Air cools at an adiabatic lapserate. However two rates apply. If air is

forced to rise but water vapour withinit does not condense the air simplyrises, expands (because it rises into anarea of lower density) and cools at arate of 10°C per kilometre. This iscalled the Dry Adiabatic Lapse Rate.However if, when the air rises, it coolssufficiently so that condensation doesoccur the air then cools at a differentrate. Latent heat is released as a resultof condensation; the air is thenwarmed and so cools at a slower rateof 5.5°C per kilometre. This is calledthe Moist (or wet) Adiabatic LapseRate. As air descends through thetropopause air warms and the reverseprocess occurs (see subtropical highpressure cell)

adobe — bricks made from sun-driedearth or clay. A lot of houses in villagesof the developing world have beenbuilt using adobe because othermaterials are not available or are fartoo expensive

advection fog — low cloud or fogproduced as a result of warm, moistair moving over cold land. Forexample when warm, humid air movesonto the land from the sea, the lowerlevels of the atmosphere are cooled by

Figure 1 � Adiabatic Lapse Rates

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contact with the ground. The air soonreaches dew point and condensationoccurs with a low fog blanketing theland. The fog is commonly 1–10metres deep but can be over 100metres deep when blanketing a city.Advection fogs roll over coastal areasespecially in winter when the groundis very cold

aeolian — relating to the wind. Forexample aeolian landforms such asand dunes or aeolian processes suchas wind erosion

aerial photograph — a photographtaken from the air (eg a vertical aerialphotograph) at heights such as 1000metres, 5000 metres etc (see figures63 and 67 colour)

aerial photography — photographytaken at a high altitude. Typically thesephotographs are taken from planes.Where photographs are takenvertically above the ground (eg at 3000metres) these are called vertical aerialphotographs

aerial roots — a type of plant root thatdoes not usually grow in the groundbut absorbs moisture from the air

aerobic — a term to describe conditionsthat exist in the presence of oxygen.An aerobic environment is one inwhich oxygen is available for life (seeanaerobic)

aerological diagram — a graph onwhich the slope of parts oftemperature and moisture profilesthat have been recorded by aradiosonde can be read andinterpreted. In this way the relativestability/instability of the atmospherecan be determined

aerosol — a particle in the atmosphere,for example a dust particle or pollen.The brown haze, especially over cities,and clouds are the result of theaccumulation of aerosols in theatmosphere. Aerosols find their wayinto the atmosphere as a result ofvolcanic eruptions and dust storms inarid and semi-arid areas. The activitiesof people also add aerosols to theatmosphere as a result of land clearing

as well as the pollutants fromindustrial activity and the burning offossil fuels such as in cars. Theseaerosols also act as condensationnuclei in the atmosphere

aestivation — see Estivation ageing population — a population

where the average age of thepopulation increases over time. Forexample if 10% of the population isover 55 years of age this year and in 10years time 15% is over 55, then this isan ageing population (see oldpopulation)

agglomeration — a term used whenvarious types of activity concentrate inone area. An example ofagglomeration is firms concentratingin an area and quite often they do sobecause they either specialise in asimilar type of economic activity or aretaking advantage of what otherbusinesses have to offer

agglomeration economy — an advant-age received from agglomeration. Forexample firms may concentrate in onearea and receive reduced transportrates, cheaper power or reduced landtax. In this sense an economy is anadvantage or benefit. Economies ofagglomeration often mean reducedcosts that may be seen as reducedprices to customers

aggradation — the building up of theland by various processes such asdeposition and mountain building.Aggradation can occur as the result ofthe deposition of sediment in a streamor by the wind to form a sand dune ora glacier forming a moraine (seedegradation)

aggrade — to build up (seeaggradation)

agistment — the grazing of animals,such as cattle, on someone else’s landfor payment. This is done, forexample, in times of drought whenone farmer pays another farmer to usetheir land as a source of pasture feed.In other circumstances cattle areagisted in the short term when afarmer may have a large number of

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cattle that need extra feed beforetransport to a market

agrarian — relating to agriculture eg theagrarian revolution

agribusiness — a type of commercialfarming. Farming is considered abusiness with land owned by largecorporations that have diversified intoagricultural activity. These types offarms are typically large scale, land isintensively farmed, there is a highinput of chemical fertilisers andpesticides, production is capitalintensive with the heavy use ofmachinery and high-technology

agricultural land use — also referredto as farming. Examples of agriculturalland use include dairy farming, wheatfarming and coffee plantations

A-horizon — the upper part of a soilprofile consisting of organic materialand where the processes of leaching,soil creep and slope wash are common.The organic activity of plant roots andthe activities of worms and insectsdominate the A-Horizon (see figure 53)

air mass — a parcel of air that hassimilar conditions at any horizontalposition even though separated bytens or hundreds of kilometres. An airmass may extend for over 1000kilometres and may extend fromground level up to 5 kilometres inaltitude. Temperature and humiditycharacteristics are similar across the airmass at 1 kilometre; temperature andhumidity conditions are similar across3 kilometres altitude etc. Air acquiresthe characteristics of the surface overwhich it passes. So a parcel of air thatlies over the Coral Sea off northeastAustralia for a few days hascharacteristics that are warm andmoist. The air mass may move ontothe coast and inland. The land thenbecomes relatively moist

air pressure — the weight of the airabove. The weight of the atmosphereexerts a pressure; this is measuredusing a barometer in units calledhectopascals (eg 1000 hPa)

albedo — the proportion of solarradiation reflected from the surface.Lighter coloured surfaces have ahigher albedo than darker colouredsurfaces

• Snow reflects 40-70% of radiation;this explains the glare ofsnowfields

• Forests reflect approximately 15%of radiation

• Tarred roads reflect 5-10% ofradiation because so muchradiation is absorbed rather thanreflected. Dark surfaces such asthese become very warm

algae — a group of simple plants thatcontain chlorophyll enabling them tophotosynthesise. Algae can be foundin aquatic areas such as rivers or anymoist areas

alkalinity — a term to describe the pH ofa soil or water; a pH over 7.2 indicatesalkaline conditions (see acid soil andpH)

alliance — a political associationbetween two ‘states’ (countries,provinces etc) for mutual benefit suchas political alliances and militaryalliances (eg ANZUS, NATO)

allochthonous — usually referring tosediment, allochthonous material isthat which has been transported fromone place, deposited and then formingrock. For example sediment transportedfrom mountains, deposited in the formof a delta, then after million of yearsforming sandstone (see autochthonous)

alluvial — related to sediment that hasbeen deposited by flowing water

alluvial fan — a low, cone-shaped,deposit on land formed where asediment-laden stream deposits itsload as a result of an abrupt change ofslope. For example in arid environmentsalluvial fans are common where amountain stream deposits its sedimenton a low-lying plain at the foot of amountain or mountain range

alluvial soil — soil that has developedfrom material than has been deposited

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by flowing water such as a stream.Alluvial soil is very fertile and is usedfor various types of intensiveagriculture such as rice growing. Alsosettlement in many developingcountries tends to be very dense onthe fertile alluvial floodplains of riverssuch as the Ganges River and riverdeltas such as the Mekong River delta(see alluvium)

alluvium — unconsolidated (loose)material, such as sand, gravel and clay,that has been deposited by water.Alluvium can be deposited on thefloodplain of a river following floods(see figure 25)

alp — referring to high mountain peakssuch as the Himalayan Alps and theEuropean Alps. In many instances‘alps’ are referred to as the pasture forcattle grazed under transhumance

alphanumeric — a location systembased on a grid. Unlike grid referencespoints are located using letters acrossthe top of a map and numbers alongthe side or sides (as in a streetdirectory)

alpine — relating to mountain environ-ments; strictly that area above the treeline and below the area of permanentsnow

altimeter — an instrument in aircraftand used by land surveyors indetermining height above sea level

altiplano — a windswept, almosttreeless, high altitude plain in Bolivia.The dominant form of land use is thatof grazing llamas, alpacas and sheep

altitude — the vertical height of the landabove sea level

Amazon River — located mainly in Brazil,South America, the Amazon is thesecond longest river in the world andwith the largest discharge of 5,600 km3

anabatic wind — a warm wind blowingupslope. When valley slopes areheated, for example by the Sun, thewarm air rises causing a wind to blowup the slope. Such warm winds are dangerous inareas prone to bushfires (see föhneffect and katabatic wind)

anabranch — the name given to astream that leaves the main riverchannel then joins up with it furtherdownstream. Anabranches are common in areassuch as where a stream (or glacier)flows into an area of much lowergradient. The low gradient and highsediment load, such as on river deltas(eg the Ganges /Brahmaputra delta) aswell as at the foot of glaciers, wherethere is often sediment-ladensnowmelt, lead to many intercon-necting and crisscrossing channels(see braided river)

anaerobic — a term used to describeconditions where oxygen is notavailable. Anaerobic conditionscommonly exist in the deep watersbehind the walls of dams and at thebottom of peat bogs and swamps(where little or no life exists) (seeaerobic)

anastomosing — referring toanastomosing channels. As somestreams divide, especially in theirlower reaches, sediment-laden watersform many interlocking channels as inbraided streams

ancillary services — additional servicesthat a firm needs to function moreeffectively — beyond the main servicesprovided to it

Angkor Wat — a stone temple inCambodia once part of the KhmerRepublic which flourished betweenthe seventh and twelfth centuries

angle of repose — usually defined asthe angle at which sediments come torest. The angle of repose is themaximum angle that grains remain inplace without collapsing downslope.However the maximum angle thatgrains are at rest may be greater thanthe angle of repose due to internalfriction and the shape of individualgrains

animate energy — human labour anddraught animals are the main forms ofanimate energy (as opposed toinanimate energy such as oil, coal andnatural gas)

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animism — a system of belief in whichnatural objects such as trees and rocksare said to have spirits

annual temperature range — thedifference between the highest andlowest temperatures over a year

Antarctic Circle — an imaginary line oflatitude at 66½°S (see Arctic Circle)

Antarctic Convergence — lies withinthe Southern Ocean surrounding theAntarctic continent, where the coldsurface waters of the south (2°C) meetthe warmer surface water of the north(4°C). This area is rich in marine lifeand forms an obvious boundarybetween flora and fauna to the northand south

Antarctic Treaty — an internationalagreement between nations for theprotection of Antarctica and Antarcticresources. The treaty was signed in 1961 with theobjective of maintaining Antarctica forpeaceful purposes and providing forthe protection of its flora and fauna. It was signed by 16 nations engaged inAntarctic research – Argentina,Australia, Belgium, Chile, (former)Czechoslovakia, Denmark, France,Japan, the Netherlands, New Zealand,Norway, Poland, South Africa, UnitedKingdom, USA and (the former) USSR. No country owns Antarctica or a pieceof Antarctica; rather various countriessuch as Australia have laid claim tovarious parts of Antarctica in the eventthat the continent may be ‘split up’ atsome future date. Australia has by farthe largest claim

antecedent drainage — a drainagesystem that has maintained its coursedespite localised uplift of land

antecedent stream — a stream that hasmaintained its course despite localiseduplift; its course has not been diverted

anthropogenic — a term used todescribe those features that are aresult of human activity. For examplean anthropogenic effect is theconstruction of buildings

anticline — the arch in a fold ofsedimentary rock where rock layers

have been forced to rise in mountainbuilding (see fold mountains)

anticyclone — an area of high pressure(see figure 26)

antipodes — places on the Earth’ssurface directly opposite each othersuch as China and Argentina. Australiais sometimes referred to by the Britishas the antipodes

ANZUS — ANZUS Council; treaty signedby Australia, New Zealand and theUnited States

apartheid — a system of racial segreg-ation; an example of this was itsadoption by the largely AfrikanerNational Party of South Africa in 1948

APEC (Asia Pacific EconomicCooperation) — created in 1993forming an important economic andtrade association for Asia-Pacificnations – New Zealand, Japan, SouthKorea, Canada, China, Taiwan, Mexico,Papua New Guinea, Chile, Thailand,Philippines, Malaysia, Singapore,Brunei and Indonesia

apedal — soil material showing nointernal organisation in the form ofpeds (see pedal). Soils dominated bysand are often apedal

aphelion — the point at which anorbiting body, such as the Earth or acomet, is furthest from the Sun. OnEarth it occurs on approximately 4 July – at 152 million kilometres

aphotic zone — area of a body of waterthat light does not penetrate, such asbelow approximately 200 metres inthe open ocean (see photic zone)

apogee — the point at which an orbitingbody, such as the Moon, is furthestfrom a planet such as the Earth

Appalachia — that area of the easternUnited States that includes the area ofthe Appalachian Mountains (includingstates such as Virginia andPennsylvania)

applied geography — the applicationof geographic knowledge and skills inthe acquiring of new knowledge andthe solving of problems in thebiophysical, social and economicenvironment. Examples where the

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application of geographic knowledgeand skills is incorporated is in theareas of town planning,Environmental Impact Statements,land use zoning, population studies,census analysis and in the large field oftourism

aquaculture — the commercial growingof marine or freshwater animals andplants in water eg oyster growing andtrout farming (see mariculture)

aquatic — a term relating to water orliving in a water environment. Forexample fish are aquatic animals (seeterrestrial)

aquiclude — an impermeable barrierthat restricts the flow of groundwaterin an aquifer. A rock type such as shalemay restrict the flow of water fromsandstone

aquifer — a permeable rock formationthat stores and transports ground-water and is often used for irrigation(eg the Great Artesian Basin inEastern Australia). Different types ofaquifers include:

• Surficial Aquifers – occur inalluvial deposits in river valleys,deltas and some sand dunes. Theselarge aquifers such as on FraserIsland (Qld) provide a permanentwater source for many perennialrivers

• Sedimentary Aquifers – occur inconsolidated sediments such assedimentary rocks as in the GreatArtesian Basin covering much ofthe eastern half

• Geologic Aquifers (or FracturedRock Aquifer) – occur in someigneous rocks that have beenmodified by Earth movements andtrapping some water. These arelimited in extent and occur far lessfrequently than other types ofaquifers

arable — a term used to describe landthat is able to grow and support crops.The land has characteristics such asgently sloping land, fertile soils and atemperate climate (one lackingextremes of temperature and rainfall)

arboriculture — the cultivation of trees(see silviculture)

arboreal — relating to treesarboretum — a collection of living plant

species such as trees and ferns forboth study and the display of theirdiversity of form

archipelago — a large group of islandssuch as the Indonesian archipelagoand Philippine archipelago

Arctic Circle — an imaginary line66½°N. North of the Arctic Circle thereis one 24-hour period when the Sundoes not set and one 24-hour periodwhen the sun does not rise

area reference — a four figure mapreference used on a topographic mapeg 2475 (see figure 40)

arête — a very sharp, rocky mountainridge in a once glaciated uplandregion

arid environment — a dry environ-ment. Arid environments such asdeserts are characterised by lowaverage annual precipitation and asparse vegetation cover

Aristarcus — Aristarcus of Samos (theMediterranean) approximately 2200years ago was the first person tosuggest that the Sun rather than theEarth is at the centre of the planetarysystem and that all the planets revolvearound the Sun rather than the Earth(see Copernicus)

arithmetic mean — the average of a setof numerical data; eg scores of 5, 8, 9,9, 10, 13 have a average or arithmeticmean of 9 – that is the sum of thescores (54) divided by the number ofscores (6)

arroyo — a dry river bed with steepsides in an arid or semi-aridenvironment. It typically flows aftershort intense bursts of rainfall; theterm is used mostly in SW USA andMexico (see wadi)

arterial roads — the main roadstransporting the bulk of vehiculartraffic

artesian well — a well that penetratesan aquiclude to reach the aquiferbelow that releases water to the

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surface that has been held underpressure

asbestos — a fibrous form of someminerals such as chrysolite, a fibrousserpentine mineral. It has been usedas a form of insulation in houses aswell as part of the constituents ofsome roofing materials. Prolongedexposure to asbestos can lead toAsbestosis as well as the cancerousMesothelioma

asbestosis — a disease of the lungscaused by the inhalation of asbestosfibres. As the fibres scar the lungchronic breathing difficulties occur

ASEAN — Association of South EastAsian Nations

Ash Wednesday — the name used torefer to the devastating fires in Victoriaand South Australia, 16 February 1983.Seventy-six people died, over 3500were injured, 17,000 homes weredestroyed and 300,000 sheep and18,000 cattle were killed

aspect — the direction that a feature,such as a building or hill slope, faces.Slopes, for example, can be describedas having a northerly aspect. This

means that the slope faces north. Theaspect of a slope influences itsmicroclimate. A north-facing slope inthe Southern Hemisphere will bewarmer than slopes with a southerlyaspect. Slopes with a northerly aspectas a result tend to be drier. Slopes arealso described as having a sheltered oran exposed aspect. A slope with asheltered aspect is protected from theelements of the weather such as strongwinds and high temperatures. Slopeswith an exposed aspect receive theextremes of weather such as high andlow temperatures and strong winds

asthenosphere — a zone of very hot,partially molten, rock within the Earth’supper mantle (extending fromapproximately 100-300 km below thesurface to a lower limit of 700 km). It isoften described as ‘plastic’ because therock seems to flow as a result of theinternal heat of the Earth – and providespart of the driving force behind platemovement over the Earth

atmosphere — the gaseous envelopsurrounding the Earth (Figure 2). TheEarth’s atmosphere consists of, byvolume, 79.1% Nitrogen, 20.9%

Figure 2 � The Atmosphere

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Oxygen, 0.03% Carbon Dioxide andtraces of other gases such as watervapour, Ozone, Argon, Krypton,Xenon and Helium. The atmosphereextends upwards of 120 km andincludes the Troposphere, theStratosphere, the Mesosphere and theThermosphere

atoll — a continuous, unbroken coralreef enclosing a lagoon

attrition — the wearing or rubbing awayby the friction of a particle or particlesagainst another. When particles suchas sand, or even large rocks, aretransported by rivers, waves, wind oreven glaciers the particles are worndown by their rubbing against eachother

Aurora Australis — white and colouredlights in the upper atmosphere (theIonosphere) south of the AntarcticCircle. Solar radiation entering theEarth’s atmosphere interacts withmolecules to produce what are alsoknown as the southern lights

Aurora Borealis — white and colouredlights in the upper atmosphere northof the Arctic Circle (see AuroraAustralis)

Australopithicus — an ancestor of thespecies Homo (of which people are apart). It is assumed thatAustralopithicus was an evolutionarydead end and was replacedapproximately 1.8 million years ago bythe species Homo

autochthonous — usually referring tosediment, autochthonous material isthat which has developed in situ (ithas not been transported to thepresent site by agents such as wind orwater). Evaporites are examples ofautochthonous materials

automation — the introduction ofmachinery into the productionprocess. Automation has increased inmany industries such as the carindustry and in the production ofelectronic equipment, with theintroduction of devices such as robotsin car production and the use ofcomputer technology. This has had theeffect of reducing production costs,increasing output and producingmaterials of a uniform quality

autotroph — an organism that is able toproduce its own food. The variousspecies of vegetation are autotrophs.They produce their own food via theprocess of photosynthesis (they arealso called self-feeders). Autotrophsare commonly referred to as ‘theproducers’ (see heterotrophs)

autumnal equinox — an event that isthe result of the Earth’s revolutionaround the Sun. In the SouthernHemisphere this event occurs 20-21March. At this time the Sun is directlyover the equator (see spring equinox)

avalanche — the fast, down slopemovement of soil and rock or snow(also called a debris avalanche)

average — see arithmetic meanazimuth — the horizontal angle

measured in a clockwise directionfrom true north to another point. As aresult the azimuth of a point of 0º isnorth, 90º is east, 180º is south

azonal soil — a young soil lackingdefinite horizons. These soils lack fulldevelopment and occur outsideclimate and vegetation zonessuggested by the zonal model of soilformation

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backswamp — low-lying,swampy areas on thefloodplain of a stream.These areas can cover awide area especiallybetween the channels of

meandering streams or the vast plainsbeyond a river’s levee bank. Theseareas are sometimes used foragriculture because of the oftenalluvial soil available or even forsettlement (although the area is veryflood prone) (see figure 25)

backwash — the return flow of waterback down the beach face after a wavehas broken (see also swash)

badlands — areas of extremely erodedland. The land shows evidence of deepgully erosion over a wide area (a termoriginally applied to the area ofsouthwest USA)

bahada — a landform at the foot of ahighland area where a number ofalluvial fans has coalesced (or joined)

balance of payments — the differencebetween the value of the import andexport of goods. A ‘favourable balanceof payments’ is when exports exceedimports of goods; an ‘unfavourablebalance of payments’ is when importsexceed exports of goods

balance of trade — the differencebetween the value of the import andexport of goods and services

ball and chain — an indiscriminateform of land clearing whereby twotractors or bulldozers, linked by achain 50 m to100 m long, with a largesold metallic ball at the centre of thechain. All in the path of the ball andchain is felled

baobab — a large tropical African treewith a very large trunk

Banksia — a native Australian plantnamed after Sir Joseph Banks (figure 3

colour). The Banksia can range inform from a shrub to a small tree. Itsconeflowers and rough bark make itdistinctive in vegetation communities.Some varieties of this species are theBanksia serrata with its distinctivecream-coloured flower cone andserrated leaves, Banksia ericifolia withits large orange coloured cone andsmall thin leaves and Banksiamarginata with its much smallercream/yellow cone and under leafsilver colour

bar — an accumulation of sediment(usually sandy material) within streamsor offshore from the beach (see figure 14)

barchan dune — a crescent-shapedsand dune moving across the surfacewith its ‘arms’ pointing downwind(typically found in the Sahara andKalahari sandy deserts in Africa) (seefigure 20)

bare fallow — a fallow period wherethe soil has no vegetation or cropcover

barefoot doctor — during the 1960sMao Tse Tung introduced a program toimprove the health of rural people.Local people were allowed to treatminor illnesses while still engaging intheir agricultural lifestyle. Thesepeople became known as barefootdoctors. There are almost threemillion barefoot doctors in Chinatoday

barrage — a large structure across ariver to both impound the water andto make the body of water deeper thanthat of the original river. Barrages havetypically been associated with thegeneration of hydroelectric power as aresult of the energy created by the riseand fall of the tides (especially) at anestuary. This energy is used to turn

B


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turbines to generate electricity (eg LaRance estuary, France)

barrier beach — a long narrow sandybeach parallel to the shore-line whichis permanently above sea level – oftenwith a lagoon between it and the landbehind. In this case it is often called abarrier island. Along the NSW coast, Australia, thereare two distinctive sand systems – aninner barrier and an outer barrier. Theouter barrier is a narrow dune systemclose to the coast developed over thelast 4000–6000 years ie after the sealevel rise following the last glaciation.The inner barrier is further inland (seenespecially on the North Coast of NSW)and about 1–2 metres higher than thesurrounding land. It is believed thatthis sand system formed as much as80,000 years ago during the lastinterglacial when sea level was about2–3 metres above present levels (seefigure 14)

barrier island — a long narrow island,parallel to the shoreline, composed ofsand, built by wave action andprotecting the coastline from erosionby wave action (see figure 14)

basalt — a fine-grained volcanic rockformed from a lava flow. The smallcrystals in basalt are the result of fastcooling near or on the Earth’s surfacethat inhibits crystal growth

baseflow — the water supplied to astream from groundwater. Baseflowprovides a constant contribution tooverall discharge in a stream. The rises and falls in the amount ofwater flowing in a stream are the result

Figure 4 � Stages in the Development of Successive Parallel Dunes

ryewhy

of rapid changes in precipitation andrunoff within the stream’s catchmentarea

base level — the lowest level to which ariver will erode. A river will erode itsbed until its outlet reaches base level.This is usually sea level. In a gradedriver base level is reached but theupper reaches of the river have thecharacteristic of the river being able totransport its load (sediment) but itdoes not have the energy to erode itsbed. In areas of internal drainage ariver’s base level may be a lake such asLake Eyre, South Australia

batholith — a large mass of igneousrock formed at great depth beneaththe Earth’s surface. It may extend fortens or hundreds of square kilometres

bathytherm — a line joining places ofequal water temperature (especially inthe oceans)

bazaar economy — an economy inwhich local trade is very informal andgoods are exchanged after much face-to-face haggling over price

beach — an accumulation of sedimentderived from a water source such as ariver or sea waves. Although sedimentis commonly sand-sized particles,beaches can be composed of largermaterials such as pebbles 5–10 cmdiameter to large boulders (see Tablepage 19).Sediment is typically moved by waves,currents or tides. Beaches are part of alarger beach system. Offshore sand canaccumulate forming an offshore barover which waves can break as thewater becomes shallower. As the waves

Met

res

10

5

0

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BeaufortForce

Wind speed(m/s)

Official windspeed

symbol onweather

map

DescriptionHow to

recognisewind speed

Comfort topeoplewalking

0 0�0.5 Calm Smoke risesvertically

Nonoticeable

wind

1 0.5�1.5 Light airmovement

Smokedrifts, leaves

move

2 1.5�3.5 Light breeze

Flags flutter,small

branchesmove

Wind felt onface

3 3.5�5.5 Gentlebreeze

Flagsextended

Clothingflaps

4 5.5�8.0 Moderatebreeze

Wind socklifted half-

way up

Hair blownabout

5 8.0�10.5 Fresh breeze

Crests(white

horses atsea)

6 10.5�13.5 Strongbreeze

Windwhistles, big

branchessway

You have tolean against

the windwhen walking

7 13.5�17.0 Near gale

Wind sockextended,

whole treessway

Umbrellasblow inside

out, difficult towalk steadily

8 17.0�20 Gale High wavesat sea

Difficult tobalance in

gusts

9 20.0�25.0 Strong galeTiles are

blown fromrooftops

People areblown over

10 More than25.0 Storm Trees

uprooted

Admiral Beaufort devised this scale for measuring winds at sea in 1805. His scale was givensymbols and adapted for use on land. We still use it today.

Source: J Frew, Geography fieldwork projects, Nelson 1999, p 34.

1 halffeather

1 fullfeather

2 fullfeathers

3 fullfeathers

1 flag

1 flagand 1

fullfeather

Figure 5 � The Beaufort Scale

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break and surge towards the shorelinethe swash brings with it sand to buildup the beach face (and the backwashreturns sand seaward). As sediment isbuilt up a large sand deposit, a berm,forms. This berm comprises what mostpeople associate as ‘the beach.’ At theback of the beach (or berm) more sanddeposits accumulate forming a seriesof sand dunes such as embryo dunesand foredunes (Figure 4). A distinctiveprofile can be built up of a beachsystem each different according to theprocesses operating and the materialsavailable (such as sand or pebbles)

beach cusp — see cuspbeach face — the zone on a beach

where the water moves up the beach(the swash) and water returns downthe slope (the backwash) to the surfzone

bearing — an angle in degrees whichgives the direction of one point on theEarth’s surface to or from anotherpoint

Beaufort scale — a scale used forrecording wind speed (Figure 5). A scale often used with each numberindicating the effect of the wind onvarious features that we can see

bed — a layer of sedimentary rockbedding plane — a flat, parallel surface

i) separating different grain sizes inrocks that have been laid down underdifferent conditions; or ii) indicatingsuccessive layers of sediment laid down

under particular depositionalenvironments (such as by a river, lakeor wind). Bedding planes can be seenon the exposed areas of rock cuttingsalong the sides of some major roads aswell as the steep walls of some rivervalleys (figure 6 colour)

bedload — the sediment carried by abody of water such as a river along itsbed or bottom. Particles that are moved in this way aretoo heavy to be transported insuspension so they slide or roll alongthe bed of the stream. A river might betransporting sediment in suspensionbut if the velocity of the flow decreasesthe river cannot carry the heavyparticles. The particles then drop tothe bed of the river and can be rolledalong in the current

bedrock — the solid rock beneathunconsolidated material such a soil

Benioff zone — a long zone that formsdeep within a subduction zone whereone plate plunges under another. It can extend to a depth of 700kilometres where heat is generateddue to friction and the radioactivedecay of sediment. The Benioff zone isalso the source of deep focusearthquakes (see figure 17)

benthic — a term used to apply tofeatures at the bottom of water bodiessuch as lakes, rivers and oceans

benthic-macro-invertebrate — bottomdwelling invertebrates in streams thatcan be seen with the naked eye.Benthic-macro-invertebrates includethe Mayfly, Stonefly and Dragonflynymphs as well as Waterstriders, WaterBeetles and Yabbies. These and otherorganisms are useful as indicators ofwater quality in many streams

benthos — a term used to refer toorganisms living at the bottom ofwater bodies

bergschrund — a crevasse occurringbetween the ice of a cirque and themountain wall behind it; this hasformed because the ice naturallymoves downslope under the influenceof gravity

Sediment texture classes and relatedparticle size

Texture Class Size of Particles(mm)

Boulders >256Cobbles 64Gravel 2Coarse Sand 0.2Fine Sand 0.02Silt 0.002Clay 0.0002Source: J.P. Harte and J.D. Taggart eds,Approaches to fieldwork in senior geography,GTANSW, 1986, page 62.

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Bermuda Triangle — an area of thewestern North Atlantic Ocean (off thesoutheast coast of the USA) where anumber of planes and ships havesupposedly disappeared. The triangle is generally bounded bythe lines between Cape Hatteras(North Carolina), Bermuda and Miami(Florida)

Bhopal — a town in India that was thesite of a major pesticide disasterDecember 3, 1984. The release of toxic fumes from afactory owned by Union Carbide led tomore than 2500 people dying and over200,000 people injured

B-horizon — a layer in a column of soilmaterial, below the A-Horizon, thathas undergone complete weathering. The character of this horizon isdependent on a number of factorssuch as parent material (bedrock),slope, climate, vegetation and the timetaken to produce this soil. For example soil developed on shalewill have a high clay content. The B-horizon shows evidence of verticallyoperating processes such leaching andilluviation (see figure 53)

biface — a stone tool that results whentwo faces have been worked orchipped away so as to give a sharpedge. Bifaces are common tools usedby early Aboriginal groups for skinninganimals and for use as weapons

bifurcation ratio — the ratio of thenumber of streams in one order to thenumber of streams in the next highestorder

bilby — a small native marsupial foundin small scattered colonies, in desertand semi-desert areas of Australia

bilateral agreement — an agreementbetween two nations (see multilateralagreement)

bilateral aid — see foreign aidbillabong — a waterhole that fills during

floods and usually formed from aformer river (meander) channel (seeoxbow lake)

bimodal — in a set of statistical datawhere there are two common scoresthe set is said to be bimodal (seemode)

binary settlement pattern — wherethere exist a few large cities and a longtail of much smaller cities (as inAustralia); (see primate city, rank size,figure 57)

bioaccumulative — the characteristic ofsome substances, such as lead (andother heavy metals), to accumulate inthe tissue matter of animals. In manyinstances, bioaccumulatives are harmfulto life

biocide — a chemical used to kill livingthings such as insects

biodiversity — the variety of alllifeforms; the plants, animals andmicro-organisms and the genes theycontain as well as the variety ofecosystems they form

biogas — gas generated from thebreakdown (fermentation) of organicwaste. The gas produced (largelyMethane) is used for heating andcooking in many rural areas ofdeveloping countries

Figure 7 � Biological Oxygen Demand for various pollutants (mg per litre)

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biogeochemical cycle — the cycling ofminerals and nutrients (organicmaterials) in the global ecosystem. Theproducts from the weathering ofmaterials and the breakdown oforganic matter are cycled and recycledthrough the atmosphere, hydrosphere,lithosphere and biosphere to maintainthe functioning of the biophysicalenvironment. Examples include the carbon cycle, thenitrogen cycle and the phosphoruscycle (see figures 9 and 46)

biological diversity — see biodiversitybiological oxygen demand — a

measure of the amount of dissolvedoxygen in waterways such as rivers(Figure 7). Such dissolved oxygen isused by fish, microorganisms as well asin the decomposition of organicmatter. There is a large BOD involvedin the breakdown of fats in water, forexample. Where there is a large BODthe loss of dissolved oxygen can lead tothe waterway being unable to supporta diverse aquatic life. In areas whereBOD is low only a small variety of low,oxygen-tolerant species survive such asin the deep, cold oxygen-poor watersbehind dam walls (see eutrophication)

biomass — the total weight of organismsin a particular area.

biome — a vegetation communityoccupying a large area of the Earth’ssurface. Examples of biomes includetropical rainforests, grasslands,tundra and temperate forests

biophysical environment — analternative term used for the naturalenvironment. The biophysical environ-ment is made up of the atmosphere,lithosphere, hydrosphere andbiosphere. There are many featuresthat make up the biophysicalenvironment. Biophysical enviro-nments include forests, deserts andoceans. Biophysical features includemountains, clouds, sand dunes, riversand plants

bioremediation — using biologicaltechniques to overcome environ-mental problems; for example

planting saltbush to address drylandsalinity; to introduce a competitor tocontrol an insect pest

biosphere — that part of the biophysicalenvironment made up of living things.The biosphere includes parts of theatmosphere, the lithosphere and thehydrosphere — because various typesof life exists is these ‘spheres’

biosphere reserve — an areaestablished with the primary aim topreserve this representative area as amajor ecological resource. The concept of Biosphere Reserveswas put forward by UNESCO inresponse to worldwide environmentaldegradation and the unacceptablyhigh rate of species extinction.Australia has twelve biospherereserves — Uluru and the TasmanianWilderness are also World HeritageSites; most are national parks

biota — plant and animal life located ina particular area at a particular time

biotic — a term used to refer to theliving parts of the biophysicalenvironment (see abiotic andecosystem)

bituminous coal — commonly knownas black coal; a higher quality coal thanlignite

black economy — that part of the jobmarket where information is providedto the government for the reason ofevading taxation. The Black Economyoperates side by side with the legaleconomy but it exists because of thelegal tax it avoids paying

black ice — a thin sheet of frost (ice)without the usual white colour usuallyassociated with frost. Black ice issometimes very difficult to see whiletravelling on roads

bloc — a group such as countries orcommercial organisations that, underformal agreement, operate as onebody with similar objectives. This is often seen as a group makingdecisions for the mutual benefit ofeach member of the group. There aretrading blocs such as OPEC andeconomic blocs such as the EuropeanUnion (EU)

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block fault — vertical movement in theEarth’s crust along almost parallelfault lines leading to a series ofuplifted blocks of land often withsteep escarpments. In many casesthese escarpments have been erodedleading to much more gentle slopesbut the fault areas can nevertheless bedetermined via geological fieldwork

block lava — lava that has solidifiedforming a rough and jagged surface(see aa)

block mountain — a mountain or areaof high relief that has been uplifted byEarth movements along fault lines

blockstream — a stream-like accumu-lation of large rocks greater than 30cm across which are more extensivedownhill than across the slope and aremore or less channeled. Blockstreamsare typical of periglacial environments

blowhole — a hole or vertical column ina sea cliff through which large wavesforce water upward by hydraulicaction

boat people — refugees that leave onecountry and arrive in another by boat.People leave their home country withvery few personal possessions and onan often less-than-seaworthy boat.Many boat people have arrived inAustralia since the 1970s fromKampuchea, Vietnam and China – andmore recently from southwest Asiasuch as Afghanistan

BOD — see biological oxygen demandbog — a lowland area saturated with

water with decaying vegetationproducing relatively acid soil material

bolson — an inland basin surroundedby mountains found in arid and semiarid environments (a term usedespecially in SW USA and Mexico)

bolus — soil material that is worked orrubbed in the hand to determine soiltexture. A palm-full of soil is collectedfrom a particular soil horizon; a smallamount of water can be added. The material is then squeezed andrubbed between the thumb andforefinger. This is a bolus. The materialis then rubbed between the thumb

and forefinger to ensure the bolus iswell-mixed. The bolus can then be rubbedbetween the palms to determine if a‘ribbon’ can be formed (ie a length ofmaterial that looks like a ‘skinnysausage’ (see soil texture)

bore — a deep drill hole tapping anaquifer (see tidal bore)

boreal — a term describing a featurethat belongs ‘in the north.’ Boreal istypically applied to those cold areas ofnorthern North America, Europe andnorthern Asia and in particular to theconiferous forests of these areas

brackish — a term used to describewater that has a high concentration ofsalt in solution but is not as saline (orsalty) as sea water

braided river — a river that divides intomany interconnected channels. Theyare typically found in areas of lowgradient and where the sediment loadof the river is high. An example wherebraided streams can be found is onlow-lying plains where a river haspassed through an area of severeerosion (eg the mouth of the GangesRiver (Padma River) and theBrahmaputra River in Bangladesh)

Brandt line — an imaginary line drawnon a world map separating developingcountries from developed countries. In1980 the Brandt Commissionpublished a report called ‘North-South’ highlighting the greatdisparities between countries invarious development indicators andparticularly the plight of thedeveloping world in terms ofmalnutrition, illiteracy, low incomesand high birth and death rates. TheBrandt line highlights the developedcountries (called The North) and thedeveloping countries (called TheSouth)

breccia — a type of rock consisting ofmany angular fragments within amuch finer matrix — very different toconglomerate rock that consists ofmuch more rounded pebbles typicallya result of fluvial erosion anddeposition

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brigalow — a type of scrub found incentral and southern Queensland andnorthern NSW. It consists mainly oflow acacia (wattle) trees and bushes

broadacre farms — commercial farmscovering a large area especially in thedrier mid-latitude areas with landdevoted to crops such as wheat andcotton

brown haze — a form of air pollutionfound especially over cities. Fineparticles in the air from natural sources,such as dust, pollens and salt, as well asfrom human sources, such as carexhausts and incineration, has theeffect of reducing visibility. Sea breezescontribute to brown haze along thecoast bringing high concentrations ofsalt onshore. Brown haze is socommon over cities now that theincreasing mix of chemical pollutantsfrom cars and industry has contributedto a much more severe type ofpollution called Photochemical Smog

built environment — that part of theenvironment around us created bypeople eg factories and cities

bund — a low earth wall constructedaround a field such as a padi field tocontrol the flow and level of waternecessary in crop production

Burgess, E.W. — in 1924 Burgessattempted to identify and explainurban areas within Chicago, USA basedupon the outward expansion of the cityand the socio-economic groupings ofits inhabitants. His research led to the development ofa model of urban structure comprisingof a series of concentric zones; themodel became known as the concentriczone model (see figure 58)

bustee — a name for shanty towns inIndia

butte — a flat topped hill that is tallerthan it is wide commonly found in aridenvironments. A butte is formedmainly by the lateral, or sideways,erosion at the base of an outlier, orsmall hill. In many cases lateralerosion has been more rapid thanerosion at the surface due to a moreerosion resistant ‘capping’ such aslaterite on the surface (see figure 20,mesa)

Buys Ballot’s Law — this law states thatif you stand with your back to the windin the Southern Hemisphere low airpressure will be on your right and highpressure will be on your left

by-law — a law made by a local authorityfor the control of its own affairs

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cadastral map — a largescale map showing landownership. Individuallandholdings can beidentified

calcareous — any subs-tance, such as a rock or soil,containing a large proportion ofcalcium carbonate

caldera — a large basin-shapeddepression resulting from theexplosion or collapse of the centre ofa volcano

Callistemon — a vegetation speciescommonly called ‘bottlebrush’

calving — the separation of ice from thefront of a glacier. Where the front ofthe glacier reaches the sea the icebreaks off and may float in the oceanin the form of an iceberg

Cambrian Period — a period of theGeological time scale extending fromabout 570 million years ago to 500million years ago. The CambrianPeriod saw an explosion in thenumber and diversity of life on Earth(see figure 27)

campos — a tropical grassland in Brazil(South America) south of the lushequatorial rainforests, similar to thesavanna in Australia

cane toad — an animal introduced intoQueensland Australia in 1935 in anattempt to control the Cane Beetlethat threatened the sugar caneindustry. Now the Cane Toad hasbecome a pest and a majorenvironmental problem as it poses aserious threat to many native animalspecies (in Queensland, northern NewSouth Wales and eastern NorthernTerritory)

canopy — the top layer of a closedforest consisting of the bulk of leavesand branches (figure 8 colour)

Cape Horn — the southern-most pointof South America

capital intensive — refers to prod-uction such as sheep farming orbuilding construction where a lot ofcapital equipment (such as machinery)is used as opposed to a lot of labour.Capital intensive production iscommon in more developed coun-tries, such as Australia (where moremachinery is used) than developingcountries such as those countries ofSoutheast Asia (where more physicallabour is used); see labour intensive

carbon credit — a permit granting theholder a right to emit a specificamount of greenhouse gas (such ascarbon dioxide and methane). The Kyoto Protocol was agreed to inDecember 1997 where it assignedamounts, or quotas, of emissionsagreed to by developed countries.Carbon credits are obtained via theprocess of carbon sequestration; ie any process that lowers theatmosphere’s concentration of green-house gases.The Australian Government hasindicated a plan to introduce ‘carboncredit trading’ in order to meetinternational obligations under theKyoto Protocol. World policy makersare in the process of creating a globalmarket for carbon.

carbon cycle — the cycling or move-ment of carbon through theenvironment (Figure 9). Carbon existsin many forms and is stored within thebiosphere, lithosphere, atmosphereand biosphere. Carbon in the form ofcarbon dioxide occurs in theatmosphere and dissolved in theoceans. A large proportion of carbon isstored within the lithosphere. Calcareous sediments on the ocean

C


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floor eventually turn to rock such aslimestone. Carbon from decomposedvegetation has formed coal seams andoil and natural gas deposits within theEarth’s crust over millions of years.These are unevenly distributed aroundthe world in areas called sedimentarybasins such as beneath the MiddleEast. Carbon is transferred throughthe biophysical environment.Following mining and its use as aheating source (such as in coal-firedpower stations) and as an energysource for transport, carbon is addedto the atmosphere.The carbon dioxide occurring naturallyin the atmosphere as well as that addedfrom the burning of fossil fuels is takenup by vegetation around the world inthe process of photosynthesis. Plantsabsorb carbon dioxide producingtissue matter. This is later returned tothe lithosphere as a result ofdecomposition.

carbon dioxide — a minor gas (byvolume) in the atmospherecomprising one carbon atom and twooxygen atoms. Carbon dioxide isstored in the lithosphere (eg as oil,coal and natural gas), in theatmosphere, in the oceans as well as inthe biosphere (eg vegetation). CarbonDioxide is released into the

atmosphere by the burning of fossilfuels and the burning and clearing ofvegetation (see carbon cycle). It is a major greenhouse gas cont-ributing to global warming (seeGreenhouse Effect)

carbonation — a process wherebydissolved carbon dioxide in water actsas a weak acid and dissolves particularminerals. Carbonation is a chemicalprocess that leads to the weathering ofminerals in some rocks. For examplethe carbon dioxide in the atmospherecan dissolve in water droplets. Thiswater becomes slightly acid (seeacidity). When this weak acid (called aweak carbonic acid) comes intocontact with carbonate minerals thatmake up limestone, for example, theseminerals dissolve. In urban areas thecements used in building materials,relying on carbonates, are dissolved bythe acid in acid rain eventuallyweakening the building structure.

carcinogen — a cancer-producingsubstance eg asbestos and radioactivematerials

cardinal points — the four maindirections shown on a compass –north, south, east and west (Figure 10)

carnivore — an organism thatconsumes meat. Carnivores, such aslions and hyenas, consume herbivores

Figure 9 � The Carbon Cycle

aryewhy

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as a food source to gain nutrients andenergy

carrying capacity — the maximumnumber, or amount of activity that theland can support as a result of factorssuch as such as climate, soil, veget-ation and water availability. Beyondthis number or amount the land isunable to cope; it responds in varioustypes of land/water/atmosphericdegradation such as accelerated soilerosion, dieback and watereutrophication

cartel — a group of individuals,companies or countries that togethercontrol the production, distribution,marketing and even pricing ofparticular goods. OPEC is an exampleof a cartel that controls aspects of oilproduction and pricing

cartographer — a person who workswith and/or constructs maps

cartography — the making of maps andgraphs for charts

cash crop — a crop grown with theobjective of producing a surplus forsale. Cash crops are grown primarily,but not always, as a single crop such assugar cane, wheat, and canola. Cash crops are characterised by a highinput of technology (such as HighYielding Varieties as a result of geneticengineering) and capital equipmentsuch as machinery. Plantations in many developingcountries are dominated by cash cropssuch as rubber, cocoa and oil palm

Casuarina — a tree species commonlycalled a ‘she-oak.’ Casuarinas can befound in a variety of environmentssuch as the taller Forest Oaks on theslopes of protected valleys and thesmaller trees on drier plateau surfaces.They are adapted to relatively dryconditions by having long thin stemsdivided into segments. When brokenthese segments reveal small leaves (lessthan a millimetre in length) to reducetranspiration loss

Figure 10 � The four, eight and sixteen point compass

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catastrophism — the ideology or beliefthat Earth surface processes are notconstant or uniform. The term is used to refer to the studyof sudden events of large magnitude –intensive processes that have the effectof altering existing processes. For example earthquakes and tropicalcyclones that occur suddenly withdevastating force altering environ-ments in such a way as to put intoplace new processes such as erosioncreating unstable hillsides or riverchannels being directed on differentpaths (see uniformitarianism)

catchment area — the total area fromwhich material is received (Figure 11).With respect to a stream, a stream’scatchment area is the total area fromwhich it receives water. The catchment may cover one squarekilometre for a suburban creek or tensof thousands of square kilometres forrivers such as the Amazon River. The catchment area of the Murray-Darling river system is over onemillion square kilometres and extendsfrom the southern part of Queenslandto most of New South Wales, northernVictoria and southeast South Australia(see total catchment area)

catena — a sequence of soil types thatoccur across a slope having developedover similar bedrock but reflectdifferences in vegetation cover,infiltration and the slope of the land

cay — a cay is a low coral island formedwhen eroded coral debris, formed bythe erosion of a coral reef, is washed toand collected in a particular area bythe action of waves. They are known ascoral cays

CBD — see Central Business DistrictCCAMLR — see Convention on the

Conservation of Antarctic MarineLiving Resources

celsius (or Centigrade) scale — atemperature scale used around theworld that shows the freezing point ofwater at 0°C and the boiling point ofwater at 100°C at sea level. With changing altitude the boiling andfreezing point of water changes. Forexample as altitude increases waterboils at a lower temperature. To convert to Fahrenheit temperaturesto Celsius see the ‘conversions’section in the Appendix of thisdictionary

census — the organised collection andcollation of population numbers of anarea such as a country

Figure 11 � Catchments

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Central America — a region of theNorth American continent that in-cludes all countries between Mexico inthe north and Panama in the southinclusive

Central Business District — the maincommercial, financial and retail area ofa town or city. The CBD is often thesite of initial settlement and with readyaccess to transport and commun-ication links for the efficient transfer ofgoods, services and information

central place — an urban centre thatserves communities in its surroundinghinterland providing central goodsand services

central place theory — in the early1930s an economic geographer,Walter Christaller, proposed an ideato explain the spatial arrangement ofurban places across the landscape. Hestated that urban centres, calledcentral places, would provide goodsand services to their hinterland. However those larger urban placesproviding higher order goods wouldhave greater trading areas becausepeople would be willing to travelgreater distances to purchase suchgoods. As a result urban places wouldbe located at distances reflecting thethreshold population needed tosupport goods and services beingprovided by the central place. The range of these goods and servicesdetermines the trading area of thatcentral place. These trading areas, inturn, are influenced by the range ofthe goods and services provided. Those centres with small thresholdpopulations and small ranges will bemore common and spaced moreclosely together; while those withlarge threshold populations and largeranges will be much fewer in numberand spaced more widely apart. In this way a hierarchy of settlementsdevelops. The theory is very unrealistic becauseof the many assumptions that have tobe made such as central places located

on a flat plain with no variation. We know however that such featuresas hills and rivers can influence thesize and spacing of settlements (seehigh order goods)

centrally planned economy — aneconomic system where the factors ofproduction (land, capital, labour andentrepreneurial skill), marketing,distribution and consumption arecontrolled by a central government.Examples of Centrally Planned Econ-omies are former communist Chinaand Cuba

centrifugal force — a force thatencourages people and economicactivity to leave an area; for examplepollution, traffic congestion, transportcosts – also called push factors. Theseforces also contribute to the process ofcounterurbanisation

centripetal force — a force that attractspeople or economic activity into anarea (eg tax incentives, access toinfrastructure, employment opportun-ities and educational facilities) — alsocalled pull factors

CFCs — Chlorofluorocarbons. A rangeof compounds of carbon, chlorine andfluorine. CFCs are used as refrigerantsin fridges, freezers and airconditioners but also in plastic foamsthat make up many disposable cupsand packaging. When released into the atmospherethe molecules that make up the CFCare split by ultraviolet radiation fromthe sun. This releases atoms ofchlorine that attack the ozonemolecules in the Stratosphere, leadingto a thinning of the ozone layer,allowing increased amounts ofpotentially harmful ultraviolet light toreach the surface of the Earth (seeOzone Hole)

chain migration — movement ofpeople (migration) from a village to alarge city in a series of steps; eg from avillage to a smaller town, a largertown, a large city

Chandler Wobble — the variation in therotation of the Earth due to a slightwandering of the poles relative to the

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Earth’s surface. The Earth’s axis‘wanders’ approximately 0º 0' 5" over aperiod of 14 months

chelate — see chelationchelation — a process in which rock

and soil material is broken down(weathered) as a result of the action oforganic material. When water passesthrough leaf litter or decomposedorganic matter generally it picks uporganic acids. These organic acidscombine with metallic elements in thesoil forming what is called a chelate.The type of organic materialinfluences the strength of this chelateand therefore the latter’s ability tobreak down the rock or soil material

cheluviation — under the influence ofgravity, the downward movement ofdissolved minerals within soilmaterial. As decomposing organicmatter produces humic acids,especially in humid environments,these acids attack clays and rockminerals releasing iron and aluminiumoxides (called sesquioxides). The deposition of this material (alongwith eluviated material) can producea variety of hardpans within a soilprofile

chemical weathering — the breakdown of minerals into more simpleminerals. Chemical weatheringincludes the processes of oxidationand carbonation. In a rock such aslimestone (CaCO3 – calcium carbon-ate) acids in water breakdown (ordissolve) the limestone. The calciumends up in solution in the water andthe carbonate is given off as a gas

chemotrophic — a term used todescribe organisms that obtain theirenergy from a source other than light.They do this by using the energy fromsimple chemical reactions

Chernobyl — a site in the Ukrainewhere one nuclear reactor hall of anuclear power plant exploded onApril 26, 1986, leading to the releaseof a radioactive cloud over the capitalKiev and later spreading over centraland northern Europe. Many cancer-related deaths have resulted

chernozem — a fine-grained fertile soil,dark brown in colour and covering anextensive area in Eastern Europe suchas the Ukraine, Romania and Hungary.These soils, often called Black Earths,are also found in the grasslands ofNorth America and Australia wheregrasses provide rich humus material inthe A-horizon to act as nutrients forany agricultural crops in these areas

chinook — a dry warm wind blowing offthe Rocky Mountains in NorthAmerica. The normally cold air overthe Rocky Mountains of the USA andCanada is warmed adiabatically as itis flows rapidly down the mountainslopes. The Chinook literally means‘snow eater’ (see föhn)

chlorofluorocarbons — see CFCs chlorophyll — the green colour in

plants from algae to trees. They absorbsunlight in the process ofphotosynthesis

C-horizon — the lower part of a soilprofile, below the B-Horizonconsisting largely of unweathered oronly partially weathered bedrock(parent material) and little or novegetation matter with the exceptionof some plant roots (see figure 53)

chloroplast — part of a plant cell wherephotosynthesis takes place

choropleth map — a map that useschanges in shading to show variationsover the area of a map. Achorchromatic map uses variouscolours to show such variations overthe map

Christaller, W. — a German geographerwho in the early 1930s proposed amodel explaining the network ofurban centres. Based on researchconducted in southern Germany heproposed that there was an orderlyspatial arrangement of urban centresover the landscape. His model becameknown as central place theory (seeLösch, A)

cirque — a bowl-shaped, steep-walledfeature on a mountain slope formedby the erosion of a small glacier –often containing a small lake (seefigure 28)

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Classification of Coasts � I

PRIMARY COASTS: CONFIGURATION RESULTING FROM NON-MARINE PROCESSES

A: Land erosion coasts. Shaped by erosion of the land surface and subsequentlydrowned by sea-level rise sinking of the land, or the melting of ice caps

i) Drowned river cut valleys � shallow estuaries; V-shaped valleys (ria coastlines suchas eastern Australia)

ii) Drowned glacial erosion coasts � deep water estuaries; U-shaped valleys (fiordssuch as the southwest coast of the South Island of New Zealand)

iii) Drowned karst topography � embayments with oval depressions such as sinkholes(eg the Dalmatian coast along the Adriatic Sea)

B: Land depressed coasts. Shaped by land-derived sediments that prograde to the sea coasts

i) River deposition coastsa) Deltaic coasts form a lobe into the sea eg Mississippi Delta, Nile Deltab) Compound alluvial fan. Coastal plain at the base of mountains eg east coast of

the South Island of New Zealandc) Outwash plain. Alluvial deposition formed on the outer margins of large glaciers

eg glaciers in Alaska ii) Glacial deposition coasts

a) Partially submerged moraine. Hummocky topography and straightened bymarine deposition and/or erosion eg Long Island, New York

b) partially submerged drumlinsiii) Wind deposition coasts

a) Dune prograded coast. Rare: part of Namibian coast (Africa)b) Dune coast. Where dunes are absorbed by a beach. The mouths of many river

valleysiv) Landslide coasts. Masses fallen from cliffed coast eg Oregon (USA)

C: Coasts shaped by volcanic activityi) Lava-flow coasts eg Hawaiiii) Volcanic collapse or explosion coasts. Concave bays on the side of a volcano eg

Hanauma Bay Honoluluiii) Tephra coasts. Where fragments of volcanic material have built up the coast eg

west MexicoD: Coasts shaped by diastrophic movements

i) Fault coast. Straight fault scarps continuing below sea-levelii) Fold coasts. Where the coast has been recently foldediii) Sedimentary intrusion coasts

a) Salt domes eg small islands in the Persian Gulfb) Mud lumps. Small islands resulting from the upthrust of mud. Short-lived eg

near the mouths of the Mississippi estuariesE: Ice coasts. Where glacier fronts extend into the sea eg along most of the Antarcticcoast

Continued next page


cirrus — a thin, wispy cloud typicallyseen at over 6 km altitude

CITES — Convention on the Inter-national Trade in Endangered Species(of wild flora and fauna). The convention seeks to protectvarious species from excessive globaltrade contributing to their endangeredstatus or their extinction

citizenship — membership of a nationstate that brings certain rights andprivileges. Active and informedcitizenship involves participation incommunity activities and public affairs(NSW Board of Studies)

Ciudades Peridisdas — an illegalsquatter settlement in Mexico City

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Classification of Coasts � II

SECONDARY COASTS: CONFIGURATIONS RESULTING MAINLY FROM MARINE AGENCIES ORORGANISMS

A: Wave erosion coastsi) Straightened by erosion. With gently sloping sea floors and rock platformsii) Coasts made irregular by erosion

B: Wave deposition coastsi) Coastal flats or plains built seaward by waves. Broad beaches upcurrent of

groynes and the flats upcurrentii) Barrier coasts. Separated from the mainland by lagoons or marshes eg eastern

NSW Australiaiii) Cuspate forelands. Large projecting sand spits with or without lagoons behindiv) Mud-flats or salt marshes eg northwest Australia

C: Coasts prograded by organismsi) coral reef coasts eg Palau and the islands of the southwest Pacific Oceanii) mangrove coasts eg Gulf of Carpentaria (northern Australia)

D: Man-made coasts. Configurations resulting mainly from human activity eg reclaimed coastlines such in the NetherlandsSource: R.U. Cooke & J.C. Doornkamp, Geomorphology in environmentalmanagement: a new introduction, Oxford University Press 1990, p272�273

civic centre — that part of a town or city(usually in the centre) where there is aconcentration of public buildings suchas the town hall, public library andcouncil offices

civics — an identifiable body ofknowledge, skills and understandingsrelating to the organisation andworking of a society, including acountry’s political and social heritage,democratic processes, government,public administration and justicesystem (NSW Board of Studies)

clastic — related to sediment or rockscomposed of fragments that have beenderived from the weathering anderosion of pre-existing sediments orrocks – typically transported by water,gravity or ice to the present site

clearfelling — the removal of all trees inan area typically as a result of the useof machinery by people

cleavage — a tendency of minerals tosplit along a particular planeaccording to their internal structure.These lines of cleavage, showing linesof weakness, are not related to largerscale features such as bedding planesor joint lines

climate — the average condition of theatmosphere over the long-term.

A place is described as having a desertclimate because it has been dry, orarid, for a long time eg for decades,hundreds or thousand of years

climate change — the long term changein the processes operating in the global atmosphere as seen in changes such as in temperature and precipitation (see figure 12‘Techniques used for determiningclimate change’, Quaternary Period)

climatic graph — a graph providing asummary of climate informationabout a place, such as temperatureand precipitation

climax community — a community oforganisms that form the final stage of anatural plant succession. Thevegetation is in balance with thesurrounding natural environment; forexample a woodland on a coastalforedune

clinometer — an instrument tomeasure the angle of a slope

closer settlement — see urbanconsolidation

cloud — concentrations of water vapourin the atmosphere (Figure 13). As air isforced to rise it cools; water vapourcondenses around condensationnuclei.

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FIGURE 12 � Techniques used for determining climate change

Climates change over the surface of the Earth over both short and long time scales.Many techniques are available to determine the chronology and changingenvironments of the Quaternary Period (the last 2 million years). Some of theseinclude:

i) Dendrochronology: also known as tree ring analysis this is an attempt tocorrelate the annual growth rings of trees with that of past temperature andprecipitation levels in an area. Reconstructing past climates in this way canextend back 3000�4000 years with some species of tree such as theBristlecone Pine in southwestern USA

ii) Varves: these are layers of sediment of different composition and texturereflecting the seasonal variations in glacial meltwaters. Coarse material isdeposited at the foot of a glacier during warmer periods because the greaterdischarge can transport heavier sediment. As temperatures cool, less waterdrains from glaciers leading to only fine sediment being transported. In thisway, pairs or couplets of alternating fine and coarse sediment reflect relativelywarm or cool temperatures

iii) Palynology: also known as pollen analysis this technique involves analysingpollen grains within sediment. Evidence of previous rainforest vegetation in apresent-day environment may be the result of local or global climate change.Used with other evidence, such conclusions can be confirmed or dismissed

iv) Macrofossils: a particular site today may be relatively warm and dry; whereasthe remains of particular fauna can suggest earlier wet conditions (such as themegafauna at Riversleigh, Queensland, Australia). Marine molluscs have beenused to indicate whether warm or cool fauna existed at a particular time

v) Radiometric Dating (or isotopic dating): this type of dating depends upon theradioactive decay of an element, such as Potassium (K) into Argon (Ar) orUranium (U) into Lead (Pb). The rate of decay of elements is known. Since the1960s K/Ar dating has been used for dating materials rich in potassium suchas basalts; Thorium/Uranium dating is used for dating corals and hencedetermining rates of sea level change. This method is useful for up to 200,000years The time interval between the present and the time when the elementwas fixed can be determined. By determining the age of material achronology of climate events can be made.

vi) Tephrochronology: volcanic eruptions can provide lava and volcanic ash thatcan act as stratigraphic markers for the Quaternary Period. This marker can bedated via K/Ar. Material above this marker is younger than the marker;material below the marker is older.

vii) Deep Sea Cores: these can be dated by such techniques as radiometric orpalaeomagnetic methods (see below). Climate-sensitive species can give anindication of temperatures in the oceans at particular times. The shells ofsome organisms such as Foraminifera coil in different directions. Forexample, with Globorotalia truncatulinoides left coiling shells indicate cooltemperatures; right coiling shells indicate warm temperatures.

viii) Oxygen Isotope Method: when ice cores are drilled into ice caps or glaciersthe ratio of two oxygen isotopes (160 and 180) within the oxygen bubblestrapped in the ice since the ice�s formation can be determined. Low 180 valuesindicate low temperatures. This method suggests that the last cold phase on Earth started approximately 75,000 years ago and ended about 11,000years ago

ix) Aeolian Sediment: when windblown, sediment can give an indication of pastclimates. In areas where very fine sediment (typical of glacial till) is found in

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vast sand sheets, such as the loess deposits in northern China and Canada,cold dry glacial conditions once prevailed � at least upwind of the siteidentified. Sediment typical of arid environments has been found in the seasadjacent to continents such as the Tasman Sea. When dated these sedimentsindicate arid conditions on that part of the continent from which the sedimentoriginated.

x) Lacustrine Sediment: evaporites indicate dry conditions in lake areas withminerals such as gypsum and halite forming as a result of high rates ofevaporation. Sandy sediments on the edges of former lakes indicate formerwet conditions with the formation of �beaches.�

xi) Palaeomagnetic Calendar: currently the Earth is said to be in a Normalmagnetic field. However, sometimes the Earth�s magnetic field reverses.Sediments consisting of iron minerals record these polarity reversals orNormal and Reversed magnetic fields. A long time scale can be determinedwith rocks dated as younger or older than these observed reversals.

xii) Geomorphic/pedologic evidence: fossil sand dunes and landforms such asthe now submerged sand dunes on the continental shelf of NW westernAustralia suggest previously low sea level and arid conditions; glacial cirquesin mountain areas suggest previous snowlines and glacial conditions wherethey may not now exist. The presence of deep weathering soil profiles maysuggest previous warm and wet conditions.

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Different types of clouds formdepending on the rate of uplift, therate of cooling, the amount of watervapour in the air, and altitude. Cumulus cloud, Stratus cloud, Cirruscloud, mist and fog are all examples ofcloud (see cirrus, cloud, conden-sation)

cloud seeding — the addition of varioussubstances such as dry ice (solid carbondioxide), silver iodide and salt into theair (by planes) to act as condensationnuclei in order to increase rainfall.Cloud seeding has been trialled by theCSIRO and is undertaken especially indrier areas

coast — that area forming the seawardlimit of the land. The coast includesthat transition zone between themainly terrestrial and mainly marineenvironments. For example the coast,or coastline, includes those coastalforms and processes such as the beach

(sand, pebbles, mud etc), sea cliffs andsand dunes which show progressivelyless marine influence and moreterrestrial influence the further inlandone moves

coastal terrain — a landscapedominated by coastal landforms (eg abeach, sea cliff and sand dunes) andcoastal processes such as beach andcliff erosion, wind deposition andwave action forming a unique anddistinctive suite of landforms(compare this with an arid terrain anda fluvial terrain). Coastal terrains maybe dominated by the sweepingzetaform beaches, sand dunes andlagoons; they may be characterised bykilometres of sea cliffs; they may showthe dense growth of mangrovecommunities and broad tidal flats. Likeall terrains a coastal terrain is areflection of the processes andavailable materials at a particular site(see figure 14)

Figure 13 � Common types of clouds

Source: J Frew, Geographical fieldwork projects, Nelson 1999, p 69

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cohort — a group of people who have acommon experience in a period oftime. Commonly used when discuss-ing population age groups (based onyears of age). For example ‘the 15years age cohort’, or ‘the 25–29 yearscohort’

col — in mountain areas a saddle-shaped gap between two mountainpeaks (see figure 28)

cold front — the boundary between anadvancing cold air mass and air aheadof it. The air behind a cold front hasvery different characteristics than theair ahead of it. Behind a cold front theair is normally cooler and often withhigher relative humidity. In Australia, cold fronts approach fromthe southwest with winds bringingcooler temperatures and sometimesprecipitation in the form of rainfalland snow.

In Australia cold fronts are the resultof the interaction between the warmerand drier air coming from the northsuch as central Australia and the coldsub-polar air from the south. The colddense air from the south forces thewarmer, less dense air of the north torise. Precipitation often results that isusually more intense but lasts for ashorter time than that of warm fronts(see precipitation and synoptic chart)

collective farming — a system ofagriculture where the land is farmedby a group of people who worktogether using shared resources,having shared and allocated tasks inproduction and sharing of materialsproduced such as food and anyprofits. Collective farms can vary insize greatly from small community-based cooperatives to large-scale

Figure 14 � Coastal Terrain

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communes such as within formerCommunist China

colluvium — deposits of material thathave been transported and depositedon a slope as a result of various typesof mass movement; for example bywater (slopewash) and gravity(slumping)

colonialism — a name given to describethe colonisation of one country (oftena developing county) by anothercountry (often a developed country)as well as the subsequent political,economic and social control thecolonising country has. The term isoften used to describe the power ofthe developed over the developingcountries during the 1700s, 1800s and1900s (see neocolonialism)

colony — i) a settlement in a newcountry by a group of people forminga distinct community. In many waysthis colony reflects major charact-eristics of the country from which thegroup originated; ii) a group of peoplewith a common heritage forming adistinctive and often isolated groupwithin a wider community

column — an example of a speleothem.A column forms as a result of thejoining of a stalactite from the ceilingand a stalagmite from the cave floor(see figure 54 colour)

columnar basalt — following theextrusion of magma cooling createslong vertical joints with hexagonalcross-sections. After erosion ofmaterial around this basalt, verticaltowers can be seen such as the Giant’sCauseway, Ireland

commensalism — a term used todescribe the close association betweentwo different species where there is abenefit to at least one of the species.For example, where an insect lives oncattle and feeds on any parasites onthe cattle; where fish in the immediatearea of a shark feed on the discardedmaterial of a shark kill; whereangelfish and coral share the samehabitat (coral providing angelfishprotection from predators, angelfishproviding food for the coral polyps)

commercial farming — the growing ofcrops or the raising of cattle for sale.Examples include in Australia aredairying, where milk is produced forsale to large urban markets, and wheatfarming where wheat is sold to local aswell as overseas markets

commercial grazing — the raising ofcattle for sale

commodity prices — prices receivedfrom the sale of primary products egcrops such as wheat and minerals suchas tin

common(s) (The Commons) —traditionally this has referred to as anarea of land that belongs to the localcommunity rather than one individualperson or group and open to be usedby all people. More recently, ‘thecommons’, or ‘global commons’ has,been recognised where globalresources such as the atmosphere,space and the oceans are consideredto belong to the global communityrather than to an individual

commune — a large area of land that isowned and controlled by thecommunity living on it. Communeshave been introduced into somecommunist countries in order toincrease food production (such asthrough collective farming). Theselarge areas of land have been self-governing with schools, healthservices and industry establishedlargely independent of nationalgovernment. The Chinese communesare an example of this

community — a naturally occurringgroup of organisms occupying aparticular environment: i) vegetation –a community is not just a stand oftrees but the suite of vegetationspecies in an area including trees,shrubs, grasses as well as the differentspecies of each (see figure 15 colour); ii) settlement – a group of people witha shared history, beliefs andaspirations. Many communities can beidentified on the basis of shared space,religion, ethnicity and socio-economicstatus

commuting — the process wherebypeople travel long distances to workfrom their place of residence

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competence — the ability of a stream totransport its sediment load. Thehigher the velocity (or energy) of thestream the greater the competenceand so the greater the load that it cancarry

composite volcano — a large volcanobuilt by the extrusion of alternatinglarge deposits of ash and lava (seeshield volcano)

concentric zone model — this modelof the internal structure of cities wasproposed by E.W. Burgess attemptingto explain land use patterns withincreasing distance from a city centre(Figure 58). The location of particularland use activities will be influencedby their economic return and theirability to pay (or bid) for a piece land.Assuming an isotropic surfaceconcentric land use zones surroundthe city. The model, although not closeto reality for most urban areas, can beused to explain the location of someland use types. Recognising variationsin the biophysical environment,government policies and humanbehaviour some understanding ofspatial distribution of economicactivity in urban areas can be achieved(see Burgess, E.W., multiple nucleimodel, sector model, figure 58)

concept diagram — a summarydiagram where the main idea (orconcept) is highlighted, often in thecentre of the diagram, with a numberof subtopics or related ideas identifiedand placed around it. For example inaddressing population (as the keyconcept) related ideas such aspopulation growth, urban sprawl, agestructure, rural-urban differences andhousing may be drawn with lineslinking the main topic and thesubtopics. In this way an orderedunderstanding and a structuredpresentation of an issue can be made

condensation — the process describingthe physical change of water vapourfrom a gas to a liquid. Condensationoccurs when the air has becomesaturated (where relative humidityexceeds 100%). When the relativehumidity of the air is 90%condensation does not occur. Whenthe air is cooled further 100% relativehumidity may be reached andcondensation may occur in the form ofcloud, mist or fog. Further coolingmay see precipitation in the form ofrainfall from clouds or even dew fromfog or mist

condensation nuclei — particles in theatmosphere such as dust and pollen

Dimensions of Continents

Source: With modifications from Jeans D. (ed) Australia: a Geography, Sydney UniversityPress, 1976

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around which water vapourcondenses to form water droplets. Itdoes not matter how much watervapour is in the air, if there is nocondensation nuclei condensation willnot occur; rainfall will be non-existent.The lack of condensation nuclei canlead to prolonged droughts (see cloudseeding)

conduction — heating as a result ofdirect contact. For example theheating of the atmosphere by directcontact with the land

Conference for SustainableDevelopment — following on fromthe Rio Conference (Earth Summit)and the Kyoto Conference the CSD washeld in Johannesburg in 2002addressing the need to improve thequality of life of people especially indeveloping countries

confluence — the point where to riversmeet to merge as one — eg where theDarling River meets the Murray Riverat Wentworth, NSW, Australia

conglomerate — a type of sedimentaryrock; a rock formed from theweathered and eroded fragments ofother rocks. Unlike other sedimentaryrocks of relatively uniform grain size

conglomerate rocks usually consist ofa mixture of larger and smallersediment

conifer — a cone-bearing tree such as apine tree. Conifers grow well in coolerclimates such as in northern NorthAmerica and Scandinavia in Europe

conservation — a management strategyto maintain the quality of an areathrough its controlled use followingan environmental ethic. This is verydifferent from preservation which hasthe philosophy of excluding all humanactivity in order to maintain an areasuch as a forest in its pristine ornatural state

conservation tillage — farming carriedout with the objective to reducevarious types of land degradationsuch as soil erosion by retaining thestubble (stalks) of harvested crops.Water is able to infiltrate into and beretained by the soil

consumers — a term used in the studyof ecosystems, used to refer to thoseorganisms that do not produce theirown food (such as plants) butconsume (eat) plants and/or otheranimals to gain food and energy. Inecosystems these are the herbivores,

Figure 17 � Plate Tectonics and Continental Drift

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carnivores and omnivores. The termalso applies to those people or groupsthat use (or consume) goods andservices — such as natural resources

contemporary geographic issue —something of concern in the local,national or global community aboutwhich there are spatial implications(Figure 16). In the world today, thequality of the environment isconsidered to be a CGI because it is ofa concern to people around the worldbut also at the local community level.Urban poverty is a CGI because manypeople are concerned about theinequalities of income in communitiesand the social problems that can arisefrom this. This is a CGI because itoccurs at a place and is of concern topeople local and global levels. Thereare many CGIs in the natural andhuman environments. Look at some ofthe CGIs that can arise as a result ofwater use (eg water supply, waterquality, flooding, irrigation andrecreation) (see figure 16)

continent — a very large body of land.There are seven — Africa, Europe,Asia, Australia, Antarctica, NorthAmerica, South America. There is nospecific upper or lower limit as to thesize of a continent. However, thesmallest continent is Australia at 7.8million km2 (including Tasmania)while Greenland is the largest island at2.1 million km2. The continents makeup more than 98% of all land.Continents extend beyond thecontinental shelf. The table on theprevious page shows variouscontinental indicators. Strictlyspeaking Europe and Asia are in factthe one continent called Eurasia (thename ‘Europe’ created in the 1700s)

continental climate — a term used todescribe the conditions as one movesfurther inland away from the coast. A continental climate has a variety ofcharacteristics

• low total annual precipitation• large annual temperature ranges

(ie hot summers, cold winters) and

• large diurnal temperature ranges(see maritime climate).

Central Asia has an extremecontinental climate with annualtemperature ranges being over 50°Cand the large distances from the sealeading to annual rainfall figures ofless than 100 mm per annum in FarWestern China

continental crust — the upper part ofthe Earth’s surface consisting of thecontinents. Continental crust is about20 km deep – much thicker thanoceanic crust (see sial)

continental drift — the processwhereby the continents drift acrossthe surface of the Earth. Continentalrocks (see sima) being less dense thanoceanic rocks (see sial) rise above theocean floor moving across the crust ofthe Earth (Figure 17). More than 200million years ago all present-day landmade up one landmass calledPangaea. This super continent thensplit into a northern landmass calledLaurasia and a southern landmasscalled Gondwana. The southerncontinents then split apart; Australiaseparating from what is now Antarcticaabout 55 million year ago. Australia isdrifting north at a rate of 7 cm a year.The mechanism for the movement ofcontinents and the plates on whichthey ‘ride’ has been confirmed withthe acceptance of plate tectonics

continental island — an island that isnear a continent but is linked to thatcontinent geologically. In almost allcases these islands are separated fromthe mainland by an arm of the oceanor shallow sea (such as Sri Lanka,Japan and the British Isles)

continentality — refers to the effect ofdistance from the sea on the climateexperienced by a place on the Earth.An area located close to the sea is saidto have a much more maritimeclimate whereas a place located muchmore inland is said to have acontinental climate. Places experiencing a continentalclimate have the following

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characteristics compared with those ofa maritime climate:

• lower average annual rainfall total• greater annual temperature range• greater diurnal temperature range

Places with continental climatesinclude inland Australia and inlandNorth America. The reason for these

climates include:• inland areas are further away from

rain bearing winds near the coast• the land heats up much more

quickly and loses its heat muchmore quickly than the sea.

As a result, more coastal locations arecooled in summer and warmed inwinter, whereas more inland areas

Figure 18 � Examples of correlation

Correlation is a measure of the relationship between one variable and another. Where onevariable and another increases there is said to be a positive correlation (eg in Graph 1 the numberof road accidents increases as the number of cars increase). Where one variable increases andthe other tends to decrease, there is said to be a negative correlation (eg in Graph 2 the numberof species tends to increase as the number of forests cleared decrease) � see Box

Correlation gives an indication ofwhether a trend can be seen in twosets of data; as variables in one set ofdata increase the variables in the otherset of data may increase or decrease �there may be no relationship at all.

However just because there is apositive or negative correlationbetween two sets of data, this does notmean that one item causes the other;where such a conclusion is drawn fromtwo unrelated sets of data, this is calleda spurious (or false) correlation � theremay be, and usually are, other factorsinvolved.

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heat up very quickly during summerand during the day; and cool downvery quickly during winter and at night

continental shelf — the area of lowgradient around the continentssubmerged by the sea. Beyond this liethe greater depths of the ocean such asthe deep ocean floor

contour interval — the vertical intervalin the height of the land as indicatedby the different contour values; egcontour values of 10 metres, 20 metres, 30 metres indicate acontour interval of 10 metres

contour line — a line joining places ofequal height above sea level

contour map — a map, using contourlines, showing the height of the landover a particular area

contract farming — a type of farmingwhere individual farmers andagribusiness companies are contrac-ted to supply food such as vegetablesand meat to large food companiesand/or supermarkets

contrail — the name given to thecondensation trail left be aircraft as aresult of water vapour condensingbehind the aircraft at high altitude

conurbation — the continuous built-upurban area, the result of the mergingof two or more urban centres (forexample the Tokyo–Yokohamaconurbation)

conurbanisation — the process of themerging of two or more previouslyindependent urban centres. In easternAustralia the continuous urban sprawlof Sydney and Newcastle may see themerging of these two urban areas intoa conurbation

convection — the upward movement ofmaterial, such as air, as a result ofheating from below. On the Earth theland tends to heat up relativelyquickly. As it does the air is heated andso becomes less dense than the airabove it. The lower air rises in what iscalled a convection current and mayproduce rainfall (see convectionalrainfall)

convectional rainfall — rainfall thatresults from air being heated by thesun, then rising, cooling andeventually producing precipitation.Convectional rainfall commonly occursin the low latitudes between 0° and 20°north and south of the equator.However it also occurs where anylocalised heating of the ground occurssuch as during summer in the mid-latitudes (see frontal rainfall,orographic rainfall, figure 50)

Convention on the Conservation ofAntarctic Marine Living Resources— a convention or agreement signedin 1982 to protect living resourcessuch as krill and whales fromoverfishing in Antarctic waters. Theprimary aim of the convention (signedby Australia) is to ensure the long-termviability of these resources in thisfragile environment

Copernicus, Nicholaus — a Polishcleric, he confirmed the hypothesis ofAristarcus (1800 years earlier) that theSun is the centre of our solar systemand that all planets rotate around theSun

coral — material formed from the hardouter skeletons of animals called coralpolyps

coral cay — see Caycorcas — salt marshes along the banks

of riverscordillera — a series of mountain

ranges consisting of near parallelridges and plateaus – for example thelarge and continuous mountain chainsof the Andes and Rocky Mountains

Coriolis force — the apparent deflec-tion of a body moving over a rotatingsurface. The Earth rotates from west toeast. In the Southern Hemisphere asair moves north or south the airappears to be deflected to the LEFT; inthe Northern Hemisphere the airappears to be deflected to the RIGHT. In the Southern Hemisphere theCoriolis force effect leads to windsblowing anticlockwise around a highpressure cell and clockwise around alow pressure cell (and vice versa in theNorthern Hemisphere)

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corporatisation — the transformationof a state owned enterprise or agencyinto a legal entity subject to companylaw, including formal separation ofownership and managementresponsibility, for example through aboard of directors or other body

corrasion — the wearing away of rockby smaller rock particles; a type ofphysical weathering

correlation — a statistical term whichprovides a measure of the degree towhich two or more features are related(Figure 18). A positive correlationexists where as one variable increasesanother variable increases. A negative correlation exists where asone variable increases another variabledecreases. Where there appears to be norelationship there is said to be zerocorrelation. However, whether there isa correlation or not between variables,there is not necessarily any causalrelationship between the two var-iables. For example, over the pastdecade incomes have increased andthe number of frog species that havebecome extinct has increased (apositive correlation). This does notmean that frog extinction hasincreased because of rising incomes

corrie — see cirquecottage industry — where people

produce goods for sale but typicallywork in their own homes and use theirown equipment. Goods are normally,but not always, sold locally. Oftengoods are sold to a retail outlet fordistribution. Cottage industriesinclude some clothes production,pottery and supply of artwork

counterurbanisation — this representsa net gain in migration down theurban hierarchy. It is not essentially areturn to rural areas but rather amovement to the coast or regionalcentres away from the major urbanmetropolitan centre. Since the 1980s there has been areturn to rural/regional areas fromurban areas because of greater crime,

pollution and congestion in the citiesand a perceived improved lifestyle inrural areas; counterurbanistion iscommon in developed countries. Exurbanisation is a related movementbut in this case people settle outsidethe outer suburban regions of themetropolitan area either in smalltowns or rural areas

country — an independent state whosesovereignty and right to self-government is recognised by othernations

coupe — an area of forest to beharvested in one operation eg an areaof 200 hectares

craton — a very large area of the Earth’ssurface that has remained geologicallystable for hundreds of millions ofyears. Mountain building has notoccurred since Precambrian times.These relatively flat ancient rocks formthe core of major continental areassuch as the Western Shield in WesternAustralia and the eastern part ofCanada

Cretaceous Period — a period ofgeologic time 144–66.4 million yearsago (see figure 27)

crevasse — a deep chasm or gap withina glacier

croft — a small parcel of land (up to 2 hectares) used for the growing ofcrops with an adjoining residence inthe Highlands of Scotland

cross section — a graph that shows theshape of the land usually drawn fromthe contours of a topographic map

crude birth rate — the number ofbirths measured against the totalpopulation. The CBR is commonlyexpressed as the number of births perthousand people in the totalpopulation

crude death rate — the number ofdeaths measured against the totalpopulation. The CDR is commonlyexpressed as the number of deaths perthousand people in the totalpopulation (see Infant Mortality rate)

cryosphere — the area of the Earth’ssurface permanently frozen eg the icecaps of Antarctica and Greenland

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negedic

cryophyte — a plant adapted to living inareas of snow or permanent ice

cuesta — a ridge with one long gentleslope and a much shorter steeperslope. These ridges are much differentfrom the more symmetrical slopes ofridges in the Eastern Highlands,Australia. Cuestas can be seen in areassuch as the Grampian Ranges insouthwest Victoria, Australia

cultivation — the preparation of theland and the growing and harvestingof crops (eg wheat cultivation)

cultural capital — people’s acquiredknowledge and skills that areincreasingly used in order to gaineconomic wealth

cultural globalisation — globalisationin the for of increased migration,tourism and telecommunications.Globalisation has much more thaneconomic and political implications.It also allows for increasingintercultural exchanges associatedwith with 'a shrinking world

cultural landscape — a term used todescribe those parts of theenvironment that have beensignificantly modified by humanactivity; this contrasts with the naturallandscape

culture — a set of common behaviourpatterns exhibited by a group

current bedding — layers formed as aresult of the accumulation of sedimentin water such as in a stream or theocean. Current bedding can be seenon the bed of streams in the form ofripple marks and in near shore areassuch as in larger sandbars. The thinlayers produced are often less than amillimetre and can give both directionand velocity of flow

cusp — a coastal feature; a crescent-shaped depression on the seawardfacing side of a sandy beach (seefigure 14)

cyanobacteria — also known as blue-green algae

cyberbia — human society living in aninformation based, electronic world

cyberspace — the area in which allcybernetic (computer) data are stored

cycle of erosion — see Davis, WilliamMorris

cyclone — an area of low pressure. A tropical cyclone is a very intensearea of low pressure occurring in thetropics

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The New Geography Dictionary 45The New Geography Dictionary 45

Darwin, Charles — in1859 Charles Darwinpublished ‘On theOrigin of Species bymeans of NaturalSelection’ launching the

theory of organic evolution andchanging the world and the way it thinksdatabase — an ordered collection of

data – such as a computer databasedatum — any feature or quantity that

acts as a reference point from whichother features are measured. Sea levelcan be considered the datum fromwhich altitude is measured

Davis, William Morris — ageologist/geomorphologist W.M. Davisprovided a new method to describeand explain the surface features of theEarth at the dawn of the 20th century.He identified a ‘geomorphic cycle’ – aprocess of landscape evolutionprogressing from the ruggedmountains of youth, to the roundedforms of maturity, to the worn-downplains of old age. What became known as ‘the cycle oferosion’ was initially proposed forhumid terrains but eventually gainedacceptance for a wide variety oflandscapes. However ‘the cycle of erosion’hindered much geomorphic researchand such a synthesising model oflandscape evolution stalled muchresearch and understanding of theland. Field studies and more empirical re-search have enhanced our knowledgeof Earth surface processes andlandscape evolution

Dead Sea — located adjacent to Jordan,Israel and Palestine, at 398 metresbelow sea level, this is the lowest point

on the Earth’s surface. Salinity levelsare up to ten times that of the oceans

debt for nature swaps — where a lowincome country agrees to protect adesignated area in return for part of itsforeign debt being paid by an agencyor organisation from a richer country

deciduous — a term used to describetrees that lose their leaves in aparticular season. In cool environments such as occursin autumn and winter, in more alpineareas and in areas of higher latitudes,it is common for particular treespecies to lose their leaves whentemperatures fall. The alpine areas of the SnowyMountains in NSW, Australia, and thehigher latitudes of Tasmania, Australiaas well as Canada and countries ofEurope are all dominated bydeciduous vegetation (see evergreen)

decile — a statistical term referring tothe tenth part in a ranked array ofdata. For example in ranked data thefirst ten values are considered to be inthe first or top decile, the next tenvalues are considered to be in thesecond or next decile

deflation — the process describingmaterial removed from the surface bywind; another term for wind erosion

defoliant — a herbicide used to removethe leaves of trees and shrubs and tokill various types of vegetation.Examples of defoliants are 2,4-D and2.4.5-T a weed killer to control woodyweeds and regrowth after clearing

deforestation — the clearing ofvegetation on a large-scale. Around theworld, forests are being cleared toaccommodate urban sprawl, agricul-ture as well as to repay foreign debt.

D


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Deforestation is most severe inrainforest areas such as in SoutheastAsia where over 300 million hectaresof land are degraded as a result ofdeforestation. The Amazon Basin and the forests ofIndonesia account for approximately50% of global deforestation

degradation — i) the wearing away orlowering of the surface of the land.Degradation can occur as a result oferosive power of water, ice or wind. The continents are being eroded ordegraded by approximately twocentimetres per year; ii) the reductionor deterioration in the quality of theEarth’s surface. Degradation can be seen in thedeteriorating quality of the land due tosoil salinity, and accelerated soilerosion

deindustrialisation — a process todescribe the decline in the importanceof manufacturing sector within theeconomy. Characteristics of countries under-going deindustrialisation include adecline in the number and percentageof the total workforce employed inmanufacturing, a decline in manufac-turing output and a decline in thenumber of manufacturing enterprises. Deindustrialisation has occurred inAustralia, for example, with thedecline in steel production inNewcastle and Wollongong and thedecline in the car industry in SouthAustralia. Many areas undergoing deindustrial-isation have high unemployment andsee shifts in the type of workundertaken by the workforce. Many

Figure 19 � Delta system

Source: E.C.F. Bird, Coasts, Second Edition, Australian National University Press, 1976, p 207

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areas see a shift in the workplaceconcentrating on the service sector

delta — a cone-shaped landformformed from the deposition ofsediment in a body of water (Figure19). A stream will flow downstreamcarrying its load of sediment. As the velocity of the stream slowsdown as it approaches and meets thesea, the stream deposits it load. It doesthis because it no longer has theenergy to carry so much sediment. The landform that results from thisdeposition is a delta – this namebecause it resembles the shape of theGreek letter delta

demographic change — the change inthe characteristics of a populationsuch as population numbers, age andsex structure and growth rates. Identifying change in populationcharacteristics is useful in predictingfuture population patterns andstructure allowing for long-termplanning by government and non-government organisations (such asanalysing census data)

demographic transition model — amodel used by population geogra-phers to describe and explain thechanging birth and death rates overtime. Initial populations are fairly stablewith high birth and high death rates.However, over time as the populationexpands, death rates slow downfollowed by declining birth rates. Low birth and death rates latercoincide with populations that growrelatively slowly. As populations grow in developedcountries, declining birth rates occurfor reasons such as lower death ratesfollowing improved health care andbirth control

demography — the study of popu-lation. In particular the manipulationof statistical data to identify patternsand trends in population data. Demographers analyse this data, notonly to describe populations but toalso make predictions as to population

trends and to provide data forcommunity planning decisions

dendritic — a term used for a riverdrainage pattern where many smallerrivers, of tributaries, flow into a largerriver. It may be seen as a tree-likepattern (see figure 22)

dendrochronology — a branch of studythat uses the analysis of tree rings as a dating technique as well as astrategy to understand earlier climaticconditions. For example widely spaced tree ringstend to indicate favourable growingconditions, a faster growing cycle, andtherefore wetter conditions. More closely spaced tree rings indicateless favourable growing conditionssuch as drought or even coolerconditions (see figure 12)

denitrification — the process wherebynitrogen is removed from the soilhaving been converted into a gas. The nitrogen would otherwise havebeen used as a nutrient for plants

dense — closely spaced. For example, adense settlement has a lot of buildingsin a small area (see sparse)

density — the number of features in anarea for example “a density of 5 buildings per km2 means that thereare on average 5 buildings in a squarekilometre” (5 per square kilometre)

deposition — the accumulation ofsediment by the action of agents suchas water and wind. Water can depositsediment to build landforms such asdeltas; wind can deposit sediment,such as sand, to build sand dunes

depositional site — in the study of soilmaterials these are areas such as riverfloodplains and coastal sand duneswhere the dominant process is that ofdeposition by wind or water or gravity. The soils have a typically uniformlycoarse or uniformly fine texture withlittle pedal development. Soils formed in depositional sitesinclude podsols within dune sands aswell as alluvial soils along river flats(see residual site and transportationalsite)

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depreciation — the reduction in thevalue of an asset as a result of its use.This is often expressed as a percentageper year. For example machinery maydepreciate in value 10% per year as aresult of its use over time

depression — an area of relatively lowatmospheric (air) pressure (also calleda low)

desert — an area where permanentvegetation cannot be supportedbecause of one or more of a number offactors eg annual precipitation may betoo low or soils may be very poor innutrients (see figure 20). There are hot deserts such as theSahara Desert in Africa and the GreatSandy Desert in Australia. There arealso cold deserts such as the Antarcticcontinent – the driest continent onEarth. In both cases, average annual precip-itation is very low. Beaches are alsoconsidered deserts because the

nutrient poor environment preventsmuch vegetation growth

desert varnish — a thin coating on rocksurfaces in arid environments. Thecoating, often less than a millimetre inthickness, is made up of varyingcombinations of silicate clays and ironand manganese oxides

desertification — the intensification orspread of arid conditions. The processof desertification can occur in alreadyarid or desert areas where averagerainfall declines over time. For example the Great Sandy andSimpson deserts of central Australiamay become even drier than they aretoday (desertification is occurring, aridconditions are more intense). Desertification can also occur as aridconditions extend over a larger area. For example over time western NewSouth Wales becomes drier thannormal; the desert appears to beexpanding.

Figure 20 � Arid Terrain

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The process of desertification hasbeen blamed on natural climaticconditions; for example high pressurecells become more intense and hencedrier in the mid-latitudes. Desertification has also been blamedon human activity in semi-arid areasaround the world; for exampleclearing of woodland in marginal areasand the movement of refugees andassociated population pressures thatfollow. Desertification has led to the loss ofmuch land around the world both foragricultural production as well as thatbeing available for settlement. East Africa, southwest USA andwestern NSW and Queensland havebeen subject to desertification

dessication — the process of dryingout; often used when referring to aridor semi-arid environments

detritus — decomposing plant andanimal material, such as leaf litter

detritivore — an animal that feeds ondead and decaying plant and animalmatter (eg in leaf litter on the forestfloor)

developing country — a term used fora country with relatively poor qualityof life as shown by varioussocioeconomic indicators such asinadequate housing, very low incomesper head of the population, disease,and low life expectancy. Developing countries in SoutheastAsia, Central and South America, andAfrica tend also to show poor levels ofenvironmental quality such as poordrinking water

development — a process of positivechange with social, economic,environmental and personal wellbeingimproving over time. Development is a dynamic processproceeding at different and unevenrates from local to global scales

Devils Lair — a cave in southwestWestern Australia with evidence ofanimal bone dating back more than30,000 years (70–2040 individualanimals per square metre).

There is the suggestion that this maybe a ‘kill site’ with evidence of toolssuch as split pointed bone (shaped bypeople) dating at 29,500 years old – animportant archaeological site

Devils Marbles — located in theNorthern Territory, Australia these arepiles of rounded granite boulders upto three metres diameter surroundedby an extensive eroded flat plain. Aborigines see them as the eggs of the‘Rainbow Serpent’

dew point — the temperature at whichthe air becomes saturated with watervapour (or relative humidity reaches100%). Below this temperaturecondensation occurs and dew forms

diastrophism — tectonic processeswithin the Earth leading to processessuch as mountain building, faultingand folding. As plates collide, such as the IndianPlate with the Asian Plate, mountainssuch as the fold mountains of theHimalayas are formed; as plates movestrains are placed on the Earth’s crustleading to faults such as those of theGreat Rift Valley in East Africa and theSan Andreas Fault of North America.These are the result of diastrophism

diatreme — a general term used for thevents through sedimentary stratacaused by volcanic activity

dieback — a process leading to thewidespread death of trees. Dieback isseen as trees prematurely losing theirleaves. The trees start to dieback from the tipsof leaves and shoots, eventually alonglonger stems and finally the wholetree. A large area of defoliated treesmay be evidence of dieback. The eucalypts (gum trees) of thenorthern and southern tablelands ofNSW as well as the southwest forestsof Western Australia are severelyaffected by dieback. The cause of dieback is not known. Ithas been attributed to various causesthat include the:

• short-term climate change such asthe drought in eastern Australia

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during the 1980s from whichcertain tree species have not beenable to recover

• age of such species reaching apoint whereby the species is nolonger viable — considering thewidespread loss of both similarspecies and species of similar ages

• large-scale clearing of surroundingland altering water balances andassociated biophysical processes

• selective removal of other speciesfollowing land clearing which, inthe past, provided mutualprotection from the invasion ofpests and disease

These are only assertions; the cause orcauses may lie elsewhere

diffusion — the spread or movement ofa feature, such as population, away

from a point such as a city orthroughout the rural hinterland. Diffusion includes the movement ofpeople and the spread of settlementover an area but it also includes thetransmission of information by wordof mouth as well as electronically suchas via the media and the Internet

dike — see dykeDiprotodon — the world’s largest

(extinct) mammal — part of Australia’sextinct megafauna 75,000 years ago. These were browsers of plants builtlike a wombat but the size of arhinoceros – an adult weighed up totwo tonnes

discharge — the amount (or volume) ofwater flowing in a river over aparticular period of time.

Figure 22 � Examples of drainage patterns

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For example the Amazon River has adischarge of approximately 5600 km3

of water per year; the Nileapproximately 90 km3. Discharge oflocal rivers is often expressed as cubicmetres per second

dispersed — spread out; as in adispersed population

dissected plateau — a once large andextensive plateau that has beeneroded by rivers forming deep andoften steep river valleys in its surface(figure 21 colour). The surface of the plateau is markedby the interfluves of these rivers. Thesimilar height of these interfluvesindicates that the land was previouslya relatively flat or level surface

dissolved oxygen — oxygen moleculesthat are dissolved in water. Dissolvedoxygen is important to aquatic life. The dissolved oxygen content of wateris higher in flowing water as there is aconstant interaction and mixingbetween the atmosphere and thewater. Low values are recorded followingoutbreaks of algae as they use upoxygen (this poses a threat to marineand river life). The very still and deep waters behindthe walls of dams have little or nodissolved oxygen. These areas aresometimes known as aquatic desertsbecause very little life exists

distribution — the spread of featuresover an area; they may be spread out(sparsely distributed) or very closetogether (dense) (see dispersed,sparse)

diurnal — relating to the differencesbetween day and night (rather thanrelating to a year)

diurnal temperature range — thedifference between the maximum day-time and minimum night-timetemperatures (see annual temperaturerange, temperature range)

diversification — i) a process where,for example, a business expands into adifferent line of business. Instead of acar manufacturer expanding by buying

up other car manufacturing busin-esses the business might expand bypurchasing or establishing an Internetcompany; ii) evidence of the greatervariety of plant and animals in an areasuch as a rainforest biome – as in adiversified ecosystem

division of labour — a term used todescribe the specialisation of labour(or the workforce) into specific partsof the production process. A single worker or group of workersmay specialise in one aspect ofproduction. This division of labour is common inthe agricultural, industrial and servicesectors of he economy. It has the effect of utilising the specificskills of individuals but can also leadto individuals gaining greater skills inspecific tasks in which they areengaged

DNA — deoxyribonucleic aciddoldrums — an area on the Earth’s

surface between 5°N and 5°S latitude.In this area the variable winds are verylight because the pressure gradient isso small and the coriolis effect isnegligible

doline — a funnel-shaped sinkholewhere a surface depression leads tosurface waters flowing rapidly into thehole beneath the surface (typical ofkarst topography)

doughnut effect — the loss ofpopulation and urban services fromthe city centre to the city outskirts

dormitory — an area where peoplesleep (eg a dormitory suburb is onewhere people live but travel toanother suburb to work)

drainage — i) the runoff of water froman area by streams; ii) the use ofartificial pipes to drain excess waterfrom the land

drainage basin — see catchment areadrainage pattern — as a result of water

flowing in channels across the land itis possible to recognise a pattern thatthe streams make (see figure 22).

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Types of drainage patterns include:annular, barbed, dendritic, parallel,pinnate, rectangular, radial and trellis. These drainage patterns give an ideaof the type of land through which thestream is passing

drainage system — the main riverchannel and all of its tributaries; thisdrainage system exists within adrainage basin and can form adistinctive drainage pattern

Dreamtime — the ancient time referredto by the Australian Aborigines of thecreation of all things. ‘The Dreaming’refers to the spiritual beliefs ofAustralian Aboriginal people

dreikanter — a stone found on thesurface of desert areas with markscharacteristic of wind abrasion

drip irrigation — the irrigation ofindividual plants by the use of a pipingsystem feeding water directly to theroots of plants (this is very different tospray irrigation)

drumlin — a smooth mound of materialdeposited by a glacier and elongatedin the direction of previous glacialmovement

dryland salinity — a type of secondarysalinity. Under normal conditions thewater table is kept below the surface asa result of deep-rooted plants takingup moisture. The clearing of these trees destroysthe root systems and so allows thewater table to slowly rise up to thesurface. Water evaporates leaving a thin film ofsalt crystals on the surface. Very littlecan grow on this saline (or salty) baresurface. The erosive action of wind and watermakes the land affected by drylandsalinity useless for activities such asagriculture. Dryland salinity is a very seriousproblem in not only Australia butworldwide (see irrigation salinity)

dual economy — where two economiesexist in the same area such as in a city.In many newly colonised countries thetraditional (indigenous) economy

exists side by side with the newintroduced economy with very littlecontact between the two

dual occupancy — an example of urbanconsolidation that has the advantageof allowing relatives to live with theirfamilies but in separate dwellings. There is also the advantage ofproviding for additional rental accom-modation for people who cannotafford their own home. Problems associated with this includeincreasing pressure on communityinfrastructure such as water supply,neighbourhood traffic congestion andrecreational amenity

dune — a landform composed primarilyof sand having been deposited bywind or water. In arid environments, such as indeserts or even the back of beaches,large deposits of sand occur as a resultdeposition by wind – (see seif duneand barchan dunes in deserts andfrontal dune and foredune onbeaches)

dune stabilisation — the prevention ofsand dune erosion by a variety oftechniques. These include planting of vegetationproviding roots to bind the sandtogether. Eventually the dune will be colonisedby deeper-rooted plants such as trees

duplex soil — a soil characterised by atexture contrast between the A- and B-horizons. Typically a coarse sandy /sandy loamoverlies a finer clay/clay loam. Theboundaries between the A- and B-horizons are clear to sharp. The distance between the bottom ofthe A- to the top of the B-horizon isless than 10 cm. In many instances the duplex is theresult of both weathering of bedrockin situ (leading to a clayey B-horizon)and surface processes such as slopewash and soil creep (leading to sandyA-horizon) — see also texture contrastsoil

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duplex texture — see duplex soil,uniform texture and gradationaltexture

duricrust — the hard surface of the landin some environments that haveformed as a result of the cementing ofiron or silica minerals. This hardcapping protects the surface fromvarious types of erosion. Examples oftypes of duricrust are silcrete andlaterite

dust bowl — originally the ‘Dust Bowl’was an agricultural area in central USAin the 1930s. A long drought saw thenatural vegetation die off and whenthe land was then ploughed again toplant crops the topsoil was lost due toprolonged wind erosion. Less fertile

subsoil was exposed which wasuseless for farming. More recently,those areas subjected to widespreadwind erosion, leading to very poorquality land, have been referred to asdust bowls

dyke — i) an artificial embankment builtto prevent the flooding of land; ii) anintrusion of igneous material whichcuts across already existing rockstructures. In many instances the moreresistant dykes can be seen as alandform rising above the generallevel of the land where less resistantmaterial has been weathered andremoved by various processes oferosion eg the Warrumbungle Moun-tains, NSW Australia

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earthflow — the downslope mass movementof waterlogged earth. Abowl-shaped scar on theland is usually leftupslope from which the

earth has detached, and a large moundof earth at the toe (bottom) of theearthflow. Earthflows are very commonin temperate areas subjected toexcessive grazing where the topsoil hasbeen left vulnerable due to loss of aprotective vegetation cover

earthquake — the result of shock wavespassing through the Earth’s crustfollowing movement within theEarth’s crust or upper mantle. The location of initial movementwithin the crust is called theearthquake’s focus and the pointimmediately above at the surface iscalled its epicentre.

Earth Summit — an internationalconference held in Rio de Janeiro(Brazil), June 1992. The objective of the conference (also known as theRio Conference) was to assess the status of global resources withinthe atmosphere, the lithosphere, thehydrosphere and the biosphere. Chaired by the then Norwegian PrimeMinister, Gro Harlem Brundtland, theconference produced a book calledOur Common Future providing aninventory of global natural resourcesand strategies to ensure their long-term viability (see Rio Declaration)

Earth System Science — the study ofthe integrated physical and socialsystems that operate on a global scale.Rather than the simplistic study ofhow people modify the biophysicalenvironment and vice-versa the earthis seen as a single integrated systemmuch like an organism as suggested

with the Gaia hypothesis. EarthSystem Science is a major discipline inattempting to understand thefunctioning of the Earth

East Antarctica — that part of theAntarctic continent also known asPeninsula Antarctica. East Antarcticaextends along its Pacific Ocean coastfrom the Ross Ice Shelf at approx-imately 160ºW longitude through tothe Ronne Ice Shelf at approximately70ºW longitude inland to the SouthPole (see West Antarctica)

East Asia — that part of Asia comprisingChina, Taiwan and Mongolia (seeSouth Asia, Southeast Asia and WestAsia)

Eastern Highlands — a much betterdescriptive term used than the ‘GreatDividing Range’ in eastern Australiaand one increasingly used – becausethere is no great dividing range alongeastern Australia but rather a series offlat to undulating highland areasseparated by broad valleys

East Pacific Rise — a mountain chainunder the eastern part of the PacificOcean extending for over 5000kilometres separating the Pacific plateto the west and the Nazca, Cocos andNorth American plates to the east (seecontinental drift, Mid-ocean Ridge,plates)

ebb tide — the falling tide (see tides)eclipse — see lunar eclipse; solar

eclipseecological dimension — in studying a

particular geographic issue the studyincludes a consideration of the bio-physical environment and inparticular relationships been peopleand the biophysical environment

ecological footprint — the hinterlandand natural resource base an urbanarea depends on to sustain itspopulation and economic activity

E


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ecological sustainability — the use ofnatural resources of the environment,such as flora, fauna, water and theatmosphere, in such a way and at sucha rate as to ensure the long-termavailability and quality of this re-source. As an environmental resourcein its own right this ensures it beingavailable for future generations

e-commerce — electronic commerce.Increasingly businesses are usingelectronic technology to conductbusiness (eg computers and email)

economic development — anunfortunate, misused term not used agreat deal today. Previously it wassynonymous with economic growth,with development based only oneconomic indicators such as GDP percapita and income levels. A muchbetter term, that reflects otherindicators such as life expectancy andlevels of political freedom, isdevelopment

economic geographer — a person whostudies the spatial patterns ofeconomic activity. Themes includeurban development, industrial activityand agricultural patterns

economic growth — a process ofincreased output of goods and services(GDP). Usually GDP is expressed as apercentage compared to the previousyear. For example ‘Economic Growthhas increased by 2%.’

economy of scale — the advantagereceived from being large. A largecompany can achieve an economy ofscale by producing goods at lowercosts as a result of purchasing its rawmaterials in bulk and so reducing itscosts. Economies of scale can lead togoods being produced more cheaplyand increasing a company’s profits

ecosphere — another name used for thebiosphere

ecosystem — a community ofinteracting plants and animals. Anecosystem includes interactionsbetween the biotic (living) parts of anarea as well as between these bioticparts and abiotic (non living) parts egsoils, rocks, streams and sunlight

ecotone — that area which marks agradual transition between twodistinctive plant communities. Theecotone is not a sharp boundary butshows gradual change in features suchas soil type, aspect and microclimateas one moves for example from awoodland to a grassland

ecotourism — tourism that is based onthe appreciation of the naturalenvironment and has, as an importantcomponent, education and theunderstanding of the naturalenvironment. The objective ofecotourism is to ensure ecologicalsustainability.

edge city — an office, entertainmentand shopping area that is primarily awork centre rather than a residentialsuburb. A place that developed tochallenge the dominance of theCentral Business District

ecumene — the inhabited areas of theEarth’s surface

edge wave — an oscillatory standingwave produced parallel to theshoreline with crests of waves at rightangles to the shoreline. They arecommon on steeper beaches andstrongly influence the location andspacing of rip currents

effective precipitation — that part ofprecipitation that is available for plantgrowth after water loss fromevaporation. Actual precipitation maybe 650 mm per year but if evaporationis 400 mm per year then the effectiveprecipitation is only 250 mm

Ehrlich, Paul — published thecontroversial book ‘The PopulationBomb’ providing convincingarguments to show that one day thehuman population on Earth must stopgrowing at its present rate as suchgrowth is unsustainable

EIS — see Environmental ImpactStatement

Ekman spiral — the swirling or spiraleffect of parts of the ocean due to theCoriolis Effect. In the middle of theNorth Atlantic Ocean ocean currentsmove in a clockwise direction. As they move the surface layers are

aryewhy

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deflected to the right. Layers below thesurface are dragged in this directiontoo. However these currents are againdeflected to the right. This continues as depth increases. Thenet effect of this spiral is for the waterto be directed to the centre of thespiral and for surface material such asany seaweed to collect there. TheSargasso Sea in the North AtlanticOcean is a result of the Ekman Spiral

El Niño — this occurs along the coastsof Peru and Ecuador in South America(Figure 23). The warm ocean currents along thecoast are replaced by cold water fromthe depths of the Pacific Ocean.

The name means ‘the Christ Child’following the fog produced by thecold current and the fact that an ElNiño event occurs around theChristmas period every 5–7 years. An El Niño event often leads to areasof higher pressure over Indonesia andnorthern Australia often leading towidespread drought in easternAustralia (see figure 23, ENSO, LaNiña)

eluviation — the downward movementof soil particles under the influence ofgravity through a soil profile (seeilluviation and figure 53)

embryo dune — a small, recentlyformed sand dune found at the back ofthe beach.

Figure 23 � El Niño/Southern Oscillation (the ENSO Cycle)

Source: J. & M. Gribbin New Scientist, 22 May 1999

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The dune is composed mainly of fine,windblown sand with little or noevidence of recent stabilisation by anycolonising grasses. After initialcolonisation and eventual stabilisationthe embryo dune may eventuallydevelop into a larger foredune

emergency aid — see foreign aidemigration — the movement of people

out of an area. Emigration can be viewed as:

• voluntary emigration such as themovement of people out of onecountry in search of a betterlifestyle, job opportunities or even afamily reunion. Such internationalemigration occurred from Europeancountries to Australia in the 1950sand more recently from areas ofSoutheast Asia

• forced emigration such as peopleleaving a country because ofreligious persecution (such asfrom the Middle East) or politicalpersecution (such as from SouthAfrica) or even environmentaldegradation (such as fromEthiopia). Such forced emigrantsare often called refugees (seeimmigration)

enclave — a small area or territorywithin a larger area or territory.Traditionally this has referred to asmall state within another such asVatican City surrounded by Rome,Italy. Enclaves can also be used to referto small groups within a citydistinguished by features such as aculture, ethnictiy or age, hence ‘ethnicenclave’

endangered species — these arespecies (plants and animals) that areunder threat from the activities ofpeople such as land clearing andpoaching. Examples include the GiantPanda (China), the Black Rhinoceros(Tanzania) and the Yellow-footed RockWallaby (Australia). The greatest threatto species around the world is due tohabitat loss as a result of forestclearance and urban sprawl

endemic — occupying a specific regiononly

endemism — belonging exclusively orconfined to a particular place

endothermic — a term applied whereheat or energy is absorbed (such as byan organism)

enhanced greenhouse effect — theresult of the addition of greenhouse

Some Endangered Species around the World

CONTINENT SPECIESEurope Hermit Beetle, Luells� Sea Anemone, Spanish Lynx, Common

Sturgen, Danube Salmon, European MinkAsia Tiger, Wild Yak, Snow Leopard, Indian Elephant, Giant Panda,

Chinese Alligator, Amber-coloured Salamander, Taiwan Macaque,Sun Bear, Mudora Crocodile, Black Spotted Cuscuss, SumatranRhinoceros, White Cockatoo, Giant Bandicoot, Grey Wolf,Prezewalski�s Horse, Orangutan

Australia Mary River Cod, Yellow-footed Rock Wallaby, Northern Hairy-noseWombat, Black-striped snake, Greater Bilby, Helmeted Honeyeater,Pygmy Possum, Mahogany Glider, Koala

North America Polar Bear, Wooping Crane, Bald Eagle, Gila Trout, North AmericanBison, Muddy rock Snail, Eastern Couga, Bolson Tortoise

South America Longhaired Spider Monkey, Greybacked Hawk, Indigo Macaw,Maned Sloth, Giant Otter, Giant Armidillo, Jaguar

Africa Cuvier�s Gazelle, Cheetah, Pygmy Hippopotomus, Gorilla, GeladaBaboon, Black Rhinoceros, Cave Catfish, African Elephant, Aye Aye(Madagascar), White Rhinoceros

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gases by human activity (seegreenhouse effect)

ENSO (El Niño – Southern Oscil-lation) — the changing conditions ofthe lower atmosphere across thePacific Ocean. The usually strongeasterly trade winds become muchweaker during an ENSO event. As aresult the atmospheric pressure overthe central Pacific Ocean is low andunusually high air pressure occursover northern Australia. Droughtconditions in eastern Australia arethen common (see El Niño, figure 23,La Niña, Walker Circulation)

environment — the biophysicalsurroundings and the community inwhich people live

environmental audit — i) an inventoryof existing environmental factors suchas soils, forest and wildlife; ii) a reviewof a company’s activities to ensure thatit is complying with existing environ-mental standards as laid down inlegislation

environmental cost — the result of anactivity that reduces environmentalquality. The construction of a watersupply dam may incur the environ-mental cost of increased soil erosion inthe area and loss of habitat

environmental ethic — having aconcern for the quality of the naturalenvironment; this environmental ethicinfluences the actions of peopletowards the environment and itsresources

environmental flow — the volume ofwater required in a river, or wetlandsgenerally, to maintain its quality. In many rivers water has beenextracted for irrigation reducing theamount of water in these rivers. This has led to the loss of aquatic life,such as fish and vegetation, and insome cases posing threats to theactivities of people such as the river’suse for recreation and as a source ofdrinking water. This is particularly the case of theMurray River, Australia. Environmentalflow in the Murray River is attemptingto be restored with government

regulation restricting the amount ofwater lost to irrigation farmers

environmental impact statement — adocument that must be prepared by acompany or organisation where aproposed development may havevarious environmental impacts. Besides giving a brief outline of theproposed development an EIS mustoutline and assess the positive andnegative effects of the proposal, anyshort- and long-term impacts, as wellas any associated local or national scaleimpacts. An EIS must be undertaken to ensureenvironmental as well as socialimplications of a proposal areconsidered as well as economic andtechnological considerations. The document must be prepared;however its findings do not have to beimplemented

environmentalism — a philosophicalconcept that stresses the importanceof the environment in the affairs ofpeople and the need to maintain thequality of the environment to ensure asustained positive quality of life of allpeople. Extreme environmentalism is knownas environmental determinism where-by it is suggested that keyenvironmental processes determinethe activities of people

environmental lapse rate — thechange in atmospheric temperaturewith height. Under normal conditionsin the atmosphere, where air is notrising, the temperature decreases withheight. The ELR varies around the world(between 6–8°C in the troposphere)but the average figure is taken as 6.5°Cper kilometre. When air is forced to rise such as byconvection, orographic uplift orfrontal uplift the lapse rate is muchdifferent (see adiabatic lapse rate)

ephemeral — short lived i) a plant thatflowers after a short period of rain; ii) a stream that flows only during orafter a brief period rain

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epicentre — the point on the Earth’ssurface directly above where anearthquake originated (focus) deepbelow the surface. The epicentre of anearthquake is usually where thestrongest force of the earthquake is felt

epicormic buds — buds under thesurface of a tree (usually the trunk ofthe tree) that sprout after the tree hasbeen damaged by fire

epiphyte — a plant that grows onanother tree using the tree to anchoritself. An orchid perched high up in atree’s canopy is an example of anepiphyte. It has attached itself to thetree only to gain sunlight and tocollect falling leaf litter and moisture

equator — an imaginary line around theEarth (0° latitude) dividing the Earthinto two hemispheres. This is properlyknown as the geographic equator (seeheat equator)

equifinality — a term used to indicatethat despite different initial conditionssimilar or identical results occur; forexample both increasing forestclearance and urban sprawl can leadto the similar end result of speciesextinction

equinox — with the tilt of the Earth atapproximately 23½°S the Sun appearsto be over the equator on two dayseach year — 21 March and 22September. In the Southern Hemisphere 21 Marchis called the Autumnal Equinox andSeptember the Spring Equinox. At these times the Sun is directly overthe equator and all places have 12hours of daylight and 12 hours ofnight

Eratosthenes — a geographer, philo-sopher and mathematician 2200 yearsago who was the first person todetermine the circumference of theEarth — with two wells, the Sun andtwo sticks. At approximately 40,000km he was right

erg — a large area covered by sand as inparts of the Sahara Desert and theNamib Desert in Africa (see figure 20)

erosion — the picking up (orentrainment) and removal of material.Erosion is a natural process and is bestcalled normal erosion. Erosion occursas a result of the action of wind, water,ice or gravity picking up material(erosion) making it available fortransport by wind, water, ice or gravity.With the activities of people such asvegetation clearing, agriculture andthe construction of roads andbuildings, normal erosion isincreased; this additional erosion as aresult of human activity beyondnormal erosion is called acceleratedsoil erosion. Examples of erosioninclude soil erosion, such as gullyerosion and deflation

erratic — a rock (or boulder) that hasbeen transported to its presentposition by a glacier that no longerexists in the area. Erratics indicate theformer presence of glaciers in an area

esker — a long sinuous (windy) hill inthe form of a sand or gravel ridgedeposited by the meltwater at thefront, or toe, of a glacier. Whenidentified today in non-glaciated areaseskers indicate the former presence ofa glacier; and so give an indication ofclimate change

estate — in agriculture, a large farmcovering a large area. In tropical andsubtropical areas these are commonlycalled plantations

estivation — a dormant state of someanimals in summer in aridenvironments during long dryperiods; a type of adaptation of desertanimals (see hibernation)

estuary — the wide, lower part of a riverwhere it meets the sea and where it isinfluenced by the properties of the sea— such as the water being relativelysaline (salty) and the water rising andfalling with tides. Many rivers in temperate latitudeshave wide estuaries where they meetthe sea. This is because, during the lastice age, rivers flowed across theexposed continental shelf and cutdeep valleys through them.

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Common Weeds in Australia and Preferred Habitat

Prickly acacia (small tree/shrub) Mitchell grasslands

Para grass (semi aquatic) Wetlands and streams

Buffel grass (ground cover) River banks in semi arid areas

Bitou Bush (small shrub) Coastal dunes (foredunes, dry heath andlittoral rainforest)

Water Hyacinth (aquatic) Still water surfaces, high in nutrients

Salvinia (aquatic) Still or slow flowing water bodies, high innutrients

When sea level rose these valleys wereflooded and became estuaries such asSydney Harbour, NSW Australia (seefigure 25)

ethnic cleansing — the annihilation, orforcible removal from a country orregion, of one ethnic group by anotheroften more dominant group

ethnic minority — a small group ofpeople in a wider communitydistinctive on the basis of acombination of features such as race,language and history

EU — European Union; an organisationcomprising 15 countries of WesternEurope where cooperation andintegration of social, economic andpolitical life is being promoted. One of the main features of the EU isthe removal of trade barriers betweenmember countries. The member countries are Spain,Sweden, Greece, Portugal, Finland,Luxembourg, France, the Netherlands,Belgium, Austria, the United Kingdom,Ireland, Germany, Denmark and Italy

eucalypt — a tree species commonlyreferred to as a ‘gum tree.’ Someexamples of Eucalypts includeBlackbutt (Eucalyptus pilularis), IronBark (Eucalyptus paniculata), RedBloodwood (Eucalyptus gummifera)and Scribbly Gum (Eucalyptushaemastoma)

eulittoral zone — the portion of thecoastal zone that extends seawardsfrom the high tide mark down to thelimit of attached plants (can be asdeep as 60 metres)

eustatic — related to worldwidechanges in sea level

eutrophication — the nutrient-enrichment of water and/or land.There is a natural level of nutrients inwater; this is called natural eutro-phication. However, when additionalnutrients are added as a result of theactivities of people, culturaleutrophication occurs. Eutrophicationresults from sewage outflows intostreams; domestic detergents andwaste from farm dairies.The addition of phosphorus andnitrogen eutrophies waterways as wellas the land. Such eutrophication canlead to algal blooms that can becometoxic. In waterways, water loses mostdissolved oxygen in breaking down thenutrients and from the photosyntheticprocess of algae. The water becomes an aquatic desertin which very little life can besupported. In a similar way, land canbe eutrophied with nutrient spills andleaks from municipal tips (seeleachate). Where these nutrients have spilt andformed part of the surface orgroundwater runoff native vegetationinvariably dies because it is notadapted to these nutrient richconditions

evaporation — the loss of moisture inits liquid form from the surface of anobject to the atmosphere in the formof water vapour (gas) — such as froma lake, river, the ocean or even soil. Water can evaporate off the surface ofleaves of plants; but the loss of

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moisture from within the plant isknown as transpiration. The loss ofmoisture and the rate of loss ofmoisture is influenced by a number offactors such as the:

• input of energy to heat the water(eg from the Sun)

• the character of the surface fromwhich the water is evaporating

• slope of the land• type of soil and • the vegetation cover

These can significantly affect the rateof evaporation. In more humidclimates precipitation exceedsevaporation (P>E); P may be 1200 mmper annum, E may be 500 mm perannum – there is excess wateravailable; that is why rivers flowpermanently. However in more arid environments(P<E); any precipitation quicklyevaporates.Precipitation may be 400 mm perannum but because of high temper-atures there may be the potential toevaporate 750 mm per annum. In these areas there is the potential toevaporate much more water than isavailable. In arid environments, such as centralAustralia, potential evaporation is high(see evapotranspiration)

evaporite — a mineral that has beendissolved in water and has precipitatedout to form a rock compound of theseminerals especially in hot arid areas —in the same way as salt crystalliseswhen sea water evaporates on a rockplatform on the coast. Sodium Chloride (common table salt)is an evaporite as is Calcium Sulphate(gypsum)

evapotranspiration — a major processin the hydrologic cycle in transferringwater from one place to another.Evapotranspiration is the combinedloss of moisture from the earth – fromthe land and water surfaces such as theoceans and lakes (evaporation) andfrom vegetation (transpiration)

evergreen — a term used for trees thatretain their leaves all year round.Evergreen trees typically occur inrelatively warm, moist areas; forexample at low elevations intemperate climates and in relativelylow latitudes where temperatureranges tend to be small

exfoliation — a type of physicalweathering where the outer layers ofrocks such as boulders peal off like thelayers of an onion. This is also calledonion skin weathering. Stresses are caused in the outer layersof the rock as a result of either heatingand cooling or the outer layers beingsubject to continuous wetting anddrying

exosphere — the outer most layer of theEarth’s atmosphere

exothermic — a term applied whereheat or energy is released (such as byan organism)

exotic — not native to an area. Exoticplant and animal species have oftenbeen introduced from another areasuch as from overseas. Examplesinclude the Cane Toad and the rabbit,and weeds Lantana and PatersonsCurse

exotic river — a river in a relatively aridarea that receives its water fromanother area usually more humid. The Nile River in Egypt is an exoticriver; it flows northward through thedeserts of Sudan and Egypt afterreceiving its water form the wetterequatorial areas of Uganda and thehighlands of Ethiopia

expatriot — a person who decides tolive or work away from his/her nativecountry. Expatriot Australians in NewGuinea, for example, are those peoplewho choose to live or work in NewGuinea after being born or living mostof their life in Australia

exponential rate — increasing at anincreasing rate; for example increasingat 5% over a 10 year period, then 9%over the next 10 year period, then 20%over the next 10 year period. This isvery different from an arithmetic

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negedic

increase where the rate of increase inconstant over the periods indicated

extensive farming/agriculture/landuse – farming carried out on very largeareas of land such as wheat farmingand beef cattle grazing. Extensivefarming is carried out because smallareas of land are not economic to farm(see intensive farming)

extrusion — the name given for theprocess of magma reaching thesurface and flowing out across theland’s surface as lava. Rocks that haveformed from the solidification of lava(eg Basalt) are called extrusive rocks(see intrusion)

exurban — an area beyond the built-uparea of an urban centre such as a city;for example settlements dominated byhobby farms on the outskirts of a cityblur the boundary between rural andurban areas (also Exurb)

exurbanisation — the growth ofsettlements beyond the official limitsof a city but still linked to the city interms of transport, employment andthe service provision (eg hobby farms)

eye — the centre of a tropical cyclonewhere air descends from the upperatmosphere filling the low pressuresystem — a calm area around whichcyclonic winds blow

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fabric — the organisationof soil particles withinsoil material. A soil canbe described as having apedal fabric where soilparticles are arranged in

natural soil aggregates called peds (seeapedal)

fabricating — see manufacturingfactory farming — raising animals in an

artificial environment. In theproduction of chickens, eggs andpork, for example, animals arerestrained in a confined environmentand fed a controlled diet. Thebuildings in which these animals arehoused as well as the proceduresundertaken in food productionresemble that of small factories. Thereis community concern as to the ethicsassociated with this type of foodproduction

faecal coliform — bacteria derivedfrom the faeces of humans and otherwarm-blooded animals (Figure 24). These bacteria enter waterways fromagricultural and stormwater runoff aswell as sewage discharge intowaterways. Faecal coliform bacteria are notpathogenic (ie they do not causeillness or disease). Rather they occurwith pathogenic organisms; so they act

as an indicator that pathogens may bepresent. Disease such as typhoid, hepatitis andgastroenteritis can occur with highfaecal coliform counts

fahrenheit scale — a temperature scaleused where the freezing point of wateris 32ºF and the boiling point of wateris 212ºF. To convert Fahrenheit temperatures toCelsius see the ‘conversions’ section inthe Appendix of this dictionary

fallow — a term used to describe landthat has been left unused so as toregain its fertility while other land maybe given over to crops

FAO — Food and AgricultureOrganisation (a United Nationsorganisation)

fathom — a measure of water depthequal to six feet in imperial measure

fault — a fracture or fractures in theEarth’s crust across which can be seenrelative displacement of the same rockunit

fauna — an alternative term for animals(see flora)

Favelas — squatter settlementssurrounding Rio de Janeiro, Brazil

federation — when Australia wasdeclared a nation on the 1st January1901. The first Federal Parliament was

F

Figure 24 � Faecal Coliform counts for selected rivers and lakes (numbers per 100 milligrams)


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opened in Melbourne on May 9th1901 (Canberra was later chosen asthe nation’s capital in 1909)

feedlot — in agriculture food such asgrains is brought to livestock such ascattle in order to fatten them beforeslaughter later to be sent to market.These areas (pens) are called feedlots

fen — a lowland area covered withshallow water with decayingvegetation producing neutral oralkaline soil material (see alkalinity)

feral — unnatural or wild eg feral catsthat have been introduced into theAustralian environment

Ferrell cell — part of the generalcirculation. The Ferrell cell is createdby the dynamics of the Earth’s rotationand differences in the density of airmoving from the south and from thenorth. At latitide 30°S where air is sinking,some air moves south; this warm, lessdense air moves to latitude 50°–60°S. When this air meets the cold, dense airmoving from the south, the less denseair is forced to rise. There is then areturn flow in the upper tropospherenorth and south. The cold dense airthen sinks. (see figure 26)

Ferrell’s law — the law or rule thatstates that if you are in the SouthernHemisphere winds are deflected to theleft while in the Northern Hemispherewinds are deflected to the right (dueto the coriolis force). This also appliesto ocean currents (see Ekman spiral)

ferricrete — an iron-rich duricrustfertility rate — the average number of

children a women can expect to have(eg a fertility rate of 2.5)

festival marketplace — an urban areathat combines retailing andentertainment, often in former railwayyards, converted non-retailingbuildings, and formerly blighted urbandistricts

fetch — the distance a wind travels overthe sea eg “the fetch of the wind is 200km”

field capacity — when soil materialcannot take up any more water.

Following infiltration as field capacityis reached water can be seen to flowacross the surface (overland flow)

fieldwork — the planned andcoordinated collecting and generatingof new information through activeinquiry via primary research

fiord — a flooded glacial valley. Duringvery cold periods of Earth history suchas the ice age, glaciers formed at highaltitudes. Many glaciers grew andreached sea level. At this time sea levelwas much lower than present becausea lot of water was trapped in ice capssuch as Antarctica. Temperatureswarmed, ice caps and glaciers meltedand the sea flooded the valleys formedby the glaciers. These flooded glacialvalleys, or fiords, are found along thecoast of Norway (in Scandinavia) andthe west coast of the South Island ofNew Zealand

firestick farming — the use of fire toburn grassland in order to captureanimals for food, to provide nutrientsto the soil or to encourage plantregrowth; this technique was practisedby traditional Aborigines in Australia(especially before white settlement)

firn — a term used to describe the snowthat falls in winter and remainsthroughout summer until thefollowing winter without becomingglacial ice

first world — a term not used widelytoday. In the past it referred tocountries such as USA, Australia, Japanand those of Western Europe. Theseindustrialised countries are nowreferred to as developed countries,The North or The Minority World (seesecond world and third world)

fissure — a long fracture in the Earth’ssurface such as on the crust or even aglacier where there is a verticaldisplacement or gap

fissure eruption — a volcanic eruptionwhere lava is extruded from a longfracture in the Earth’s surface — suchas along an ocean ridge beneath theoceans and across Iceland rather thanfrom a single volcano (see extrusion)

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Flandrian transgression — a term usedmostly in Europe to describe the globalrise in sea level after the last glacialperiod approximately 10,000 years BP.During the last glacial period a greatvolume of water was locked up inglaciers as well as the Greenland andAntarctic ice caps. A marked regression occurred with sealevels falling approximately 150 m. Astemperatures warmed the ice meltedand sea levels began to risesubmerging the previously exposedcontinental shelves and drowningriver valleys and glacial valleys. Tasmania and Papua New Guineabecame separated from the Australianmainland at this time, as did the BritishIsles from Europe, and Sri Lanka fromIndia (see ice age)

flocculation — the process wherebyparticles adhere or clump togetherforming large substances thateventually settle out in a fluid. An example of flocculation is in sewagetreatment. A powder called alum isadded to sewage in a sewage treatment

plant. The electrically charged particlesof the alum attract the solids within thesewage forming heavier clumps thatsettle out, sink to the bottom of atreatment tank and can then beremoved. The use of Alum is being phased out infavour of alternative flocculants

floodplain — the low-lying landadjacent to a river channel inundatedby water during flood periods and onwhich alluvium is deposited (seefigure 25). The processes of floodplainsedimentation are varied. Some arebuilt up by lateral deposition on theslip-off slope of meanders; others areformed where channels switchbetween braided reaches. Overbankdeposits from flood periods typicallyprovide small amounts of floodplainmaterial; indeed some floods arehighly erosive events

flood pulse — description of aparticular flow event in the flowrecord of a river

flora — an alternative term forvegetation (see fauna)

Figure 25 � Fluvial Terrain

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flow-line map — a type of map thatshows the direction of movementand/or the quantity of movementbetween places

fluvial — relating to rivers eg fluviallandforms are those created by theaction of rivers (see figure 25)

fluvial erosion — erosion that is theresult of fluvial (or river) processes.The erosion of a riverbank can be theresult of high velocity water flow; thescouring and wearing down of theriverbed by rocks is the result of fluvialerosion

focus — the focus of an earthquake isthe point below the Earth’s surfacewhere the earthquake occurred —directly below the epicentre; the focusmay be at 10, 20, 100, 200 or morekilometres deep

föhn effect — a warm, dry wind blowingdown the leeward slope of a mountainarea. The air is warm because of thesubsiding air in the atmosphere beingcompressed and therefore heated up(see also chinook)

fold — a deformation in the Earth’s crustwhere lateral (sideways) pressure hascompressed bedding planes to formfolds. Resulting landforms can rangefrom small hills to high mountains

fold mountains — mountains that arethe result of crustal movement withinthe Earth forcing the land to rise in aseries of folds called anticlines andsynclines. Mountains such as the Himalayas arefold mountains where one lithosphericplate has collided with another forcingthe land to rise forming the Himalayas. The Himalayas are built up of seafloorsediments squeezed up like toothpastebetween two lithospheric plates (seecontinental drift)

food chain — the observed relationshipbetween living organisms where oneliving organism is dependent onanother as a food source (eg an anteaten by a lizard, the lizard in turneaten by a cat). (see food web)

food web — the series of interconnectedfood chains within an ecosystem; one

food source within a food chain maybe a food source in other foodchains

footloose industry — industries thatcan be located without particularreference to raw materials, energy ormarkets. Sophisticated infrastructureallows many industries to change theirlocation according to perceived locallyadvantageous circumstances

foredune — the large dunes at the backof beaches and within which densevegetation is growing. They aretypically the result of a prolongedperiod of deposition and the processof plant succession that may havedeveloped a climax community.Foredunes can be very large eg 20–30metres high (see figures 4 and 14)

foreign aid — assistance given topoorer countries of the world in theform of grants and low interest loans.There are different types of aid:

• Bilateral Aid: it is aid provided byone government to anothergovernment

• Emergency Aid: aid in the form offood, clothing and medicinesfollowing disasters such as floodsand earthquakes

• Multilateral Aid: where aid is givenfrom a number of internationalorganisations such as the UnitedNations via the InternationalMonetary Fund

• Tied Aid: aid is given with thecountry giving the aid settingconditions that must be met by thecountry receiving the aid. Forexample, aid given for bridge ordam construction might be givenon the condition that the countrygiving the aid has access to portfacilities

• Untied Aid: where a countryreceiving aid in the form of moneyis free to spend this on any projectit wishes

foreshore — the area of beach betweenhigh and low water marks

forest — a continuous area of tree coverwhere the dominant tree species range

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between 30 and 70 metres high andwhere the density of the canopy covermay be between 30% and 100%. As a result, there are many differenttypes of forests depending onstructure (height and density) andspecies eg tall open forests and closedforests (as in rainforests) andtemperate forests where these moresparse forests are dominated byeucalypts such as in SE and SWAustralia

formal region — an area of the Earth’ssurface marked by relatively uniformcharacteristics. In many cases, formalregions are distinguished by theirbiophysical characteristics and showclear and concise boundaries such asbeing marked by a catchmentboundary, a river, a type of soil type orgeology (see functional region)

formal sector — that part of theeconomy that makes up the officialpaid workforce. People working in theprimary, secondary and tertiary sectorsthat are paid for their work and payofficial taxes belong to the formalsector. The types of jobs in this sectorinclude doctors, secretaries andlabourers (see informal sector)

fossil fuel — a non-renewable naturalresource such as oil, coal and naturalgas. Fossil fuels have been producedover millions of years following thedecomposition of living matter such asvegetation. Fossil fuels are typicallyfound in sedimentary basins beneaththe Earth’s surface.

franchise — a small business set upwhere the business agrees to use thetrademark of a larger business anddistribute its product. As such, theremay be many small businesses of thesame name, each operating indepen-dently, but agreeing to abide by thelarger company’s standards andquality of service

freehold tenure — land ownedprivately (see leasehold land)

front — the boundary between twocontrasting air masses (see cold front;warm front)

frontal dune — a large sand dune at theback of the beach that has recentlybeen stabilised by vegetation (asdistinct from the much smallerembryo dune. The frontal dune is themost seaward of the large stabiliseddunes and is subject to the erosivepower of waves

frontal rainfall — rainfall that resultsfrom the interaction of two contrastingair masses. Frontal rainfall can resultfrom the passage of a cold front overan area. As a parcel of cold, dense airmoves towards an area with warmer,less dense air, the less dense air isforced to rise. As the air rises it cools, eventuallyforms clouds, and may rain. This iscalled frontal rainfall. Rainfall tends tocontinue for an extended period oftime such as a week compared to themore brief episodes associated withconvectional rainfall (see figure 50)

frontal uplift — the forced rising of airas a result of the different air densities(see frontal rainfall)

frost shattering — an example ofweathering common in cold climatessuch as in glacial and periglacialenvironments and those of highaltitude areas, especially above thesnowline.

Estimates of Fuelwood Consumptionin Selected Countries

Country Wood as a % of total energy consumption

Mali 97

Nepal 98

Rwanda 96

Chad 94

Tanzania 94

Burkina Faso 94

Ethiopia 93

Somalia 90

Burundi 89

Niger 87


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negedi

Water can exist in a liquid state duringthe day in some of these areas. However during the night, lowertemperatures can lead to any water inthe cracks of rocks to freeze. The expansion of the ice splits orshatters the rock into smaller pieces

fuelwood — wood that is collected orgrown to be burned to provide energyfor heating and cooking. Fuelwood isused extensively in developingcountries

fumerole — a small vent in the Earth’ssurface through which hot steam andother gasses pass. They are muchsmaller than volcanoes and can occuron the sides of volcanoes

functional diversity — the charact-eristic of a place where a variety ofdifferent economic, social and politicalactivities occur; most often associatedwith urban places

functional region — an area of theEarth’s surface showing distinctive

interrelationships which highlight itsfunction; for example

• a city shows trade and commun-ication flows, the movement ofpeople and the relationshipsbetween people and the natural,economic, social and politicalenvironments) and

• a catchment area shows linkagesbetween features such astopography, vegetation, soil andvarious land use types)

fungi — organisms such as mushroomsand mildews – neither plant noranimal. Fungi are important in theenvironment in that they decompose(break down) organic matter, such ason the floor of a rainforest, and returnnutrients to the soil and eventuallyvegetation

fungicide — Fungi can producediseases. Various chemicals, calledfungicides, are used to control thesediseases

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G7 (Group of Seven) — agroup consisting of theworld’s seven mostindustrialised nationsformed in 1975(Germany, Canada, USA,

France, Italy, Japan and the UnitedKingdom)

G8 (Group of 8) — the countriesindicated in G7 with the addition ofRussia

Gaia hypothesis — the idea that theEarth is one large living organismacting as a single system. As such, aspects of the atmosphere,lithosphere, hydrosphere andbiosphere are so intricately intercon-nected that, not only is there aresponse by one of these spheres tochanges in the other, but such globalresponses can be due to localdisruptions. Proposed initially by James Lovelockthe name is derived from ‘Gaia’ theGreek Earth Goddess. The Gaia hypothesis lies at the heart ofmany environmental philosophieswhere understandings and decisionsare based on the idea that any impacton the local or global environmentwill see a response by the Earth (iefrom Gaia, the Earth Goddess)

gallery forest — the long continuouscover of dense trees along the banks ofsome rivers especially in an otherwisedry environment. For example a‘ribbon’ of trees can be seen windingacross the land following the path ofan unseen river. These can beparticularly seen with the aid of aerialphotographs

gated communities — or common-interest developments (CIDs) promoteexclusiveness, amenities and security.In extreme cases computers check

entry cards, laser beams sweep theperimeter, and TV cameras monitorthe movement of people

GATT — General Agreement on Tariffsand Trade (UN)

gazetteer — a book providing analphabetical list of places and featureson the Earth’s surface as well asadditional explanatory information

GDP — Gross Domestic Product. This isthe total value of goods and servicesproduced by a country. GrossDomestic Product per capita is ameasure of GDP divided by the totalpopulation

gelifluction — a type of solifluctiontypically in periglacial areas. Waterwithin the regolith accumulates abovethe level of permafrost as well as frommelting lenses of ice within the soil.The body of the regolith above thepermafrost moves downslope as aslow-moving mass (eg 1–10 cm peryear)

general circulation — the circulationor movement of air in the atmosphere— both vertically and horizontally; theresult of the variation in the heating ofthe atmosphere between latitudes aswell as the rotation of the Earth (seefigure 26). The Sun’s rays are most intense in thelow latitudes (eg tropical latitudes).The warm air rises forming areas oflow atmospheric pressure. At the polesthe air sinks forming an area of highpressure.However between the equatorial andpolar latitudes the Earth’s rotationinfluences air movement. The air rises in equatorial latitudesthrough the troposphere. When itreaches the tropopause the air movesnorth and south (because it cannotnormally break through this inversion

G


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layer). In the Southern Hemisphere,for example, this cold air sinks atapproximately latitude 20–30°S formingan area of high pressure. Some airreturns to the equator in the form ofthe southeast trade winds completingwhat is called the Hadley cell.Some of this (warm) air of thesubtropical high pressure cell movessouth and is deflected to the leftforming the strong westerly winds atapproximately latitude 40°–60°S. Cold air coming from the polarlatitudes forces the warmer, less denseair ahead of it to rise. This area of lowpressure with its associated cold frontscompletes what is called the Ferrellcell. The cold subsiding air over thepolar latitudes forms an area of highpressure. The cold air moves north tomeet the rising limb of the Ferrell cell. Some of the air that is forced to risereturns to the polar latitudes tocomplete the Polar cell

genetic engineering — a name given tothe wide variety of techniques thattake a gene from one cell and insert itinto another cell. As a gene enters a cell it can changethe way that cell works. A controversial technique, geneticengineering can be used to artificiallycreate new medicines and medicalprocedures; it can be used tomanipulate the genes in the cells ofcrops producing new and newvarieties of crops

genome — the genetic material that ischaracteristic of a particular species. A major international effort hassucceeded in mapping (or identifying)the human genome. In doing this it is possible to identifyspecific genes responsible for humantraits such as hair colour as well asthose responsible for the occurrenceof specific diseases

Figure 26 � The general circulation of the atmosphere

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gentrification — the transformation ofan urban area by replacing an olderestablished socioeconomic group orage group with that of a youngergroup. Often the average age of thearea falls, average incomes are higherand the residential areas undergorestoration

geochronology — the study of determ-ining the age of the Earth. Geochronology uses relative datingtechniques as well as absolute datingtechniques. Relative dating attempts toplace features in chronological ordersuch as with the use of tree rings andvarves; whereas absolute datingattempts to give a precise dateexpressed in years such as withradiocarbon dating and potassium-argon dating (see figure 12)

geographic issue — an area of concernthat people may have about aspects ofthe biophysical environment or socialenvironment which can be inves-tigated from a spatial dimension orecological dimension (see contem-porary geographic issue)

geographical mile — a measure oflength equivalent to 1" (one minute)of latitude (ie 1/60th of a degree).Although this distance varies betweenthe equator and the poles, it isgenerally considered to beapproximately 6,080 feet (or 1853metres)

geographic information system (GIS)— a computer system which canreceive, analyse, manipulate anddisplay geographic information

geography — at its simplest formgeography is concerned with place;that is where things are. The disciplineof geography has changed over timereflecting social, economic andpolitical concerns of the day. The qualitative or descriptiveapproach to geography in themorphological tradition of the 1940sand 1950s was characterised by thedetailed description of landscapes andlandforms; the process tradition of the1960s and 1970s identified anddescribed the processes in and

features such as rivers, coasts, desertsurban areas etc. The more quantitative approach sincethe 1980s saw the increased use ofstatistical analysis and the use ofcomputer technology. In all, geography is attempting toidentify and describe patterns on theEarth’s surface and explain theirspatial patterns and temporalchanges. In doing this geography’s chiefconcern is that of the totalenvironment – the natural world, suchas rainforests, the modified world,such as agricultural areas, and thatworld created by people, such asurban communities. Although there are various branches ofgeography such as physicalgeography, human geography andpolitical geography, in all casesgeography is about identifying andexplaining patterns and offeringsustainable solutions to provide for anincreasing quality of life of people. The last decade of the twentiethcentury focussed on the concept of asustainable world. The world may well be closing in withthe explosion of information andcommunication technology. However geography of the twenty-firstcentury will increasingly address thepower and position of the nation stateand the quality of lives of people in anincreasingly polarised world – despitethe pleas of the ‘globalists’ and‘economic rationalists’

geoid — a term used to describe theshape of the Earth used nowadays todescribe an Earth-shaped body. The Earth’s is pear-shaped because ofthe slightly greater diameter of theEarth just south of the equator. This iscalled an oblate spheroid.

geological time scale — a scalerecording the history of the Earth atwell-defined time intervals (Figure 27). Geologic time extends from the periodof time before the Precambrian Period4.5 billion years ago to approximately

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570 million years ago. The CambrianPeriod followed marked by anexplosion of life forms. The Cambrian Period to the presentday is marked by Periods indicatingthe emergence of distinctive life formseg The Silurian Period (the age offishes, 430–395 million years ago). The most recent Period is theQuaternary Period (2.8 million yearsago to the present). The QuaternaryPeriod is marked by the PleistoceneEpoch and the Holocene Epoch thatbegan at about 10,000 years ago – andincludes the present day

geomorphology — a field of studywhich attempts to describe andunderstand the natural features of andthe processes operating on, theEarth’s surface. For example, a coastal geomorph-ologist describes coastal environmentsand landforms such as beaches, waves,sand dunes and rock platforms andattempts to provide explanations forthese features

geophagy — eating dirt or claygeophyte — a plant that has parts

beneath the ground surface that cansurvive after that part above theground has died off

geopolitics — the name given to thatbranch of geography, political geo-graphy, concerned with the changingsocial, economic and political face ofregions and/or countries around theworld. Geopolitics addresses the powerrelationships between nations as wellas the strategic decisions of nations tosustain or increase their power baseon a regional or global scale

geosyncline — a depression in theEarth’s surface extending for 100s or1000s of square kilometres into whichvast quantities of sediment accumulateover millions of years. Sedimentaryrocks develop to depths of severalkilometres below the surface.Geosynclines are ideal sites for theaccumulation of hydrocarbons whichinclude economically viable reserves

Figure 28 � A Glacial Terrain

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of reserves of oil, coal or natural gassuch as within the Sydney Basin, NSWAustralia and beneath parts of theMiddle East

geothermal energy — heat energyobtained from within the Earth. Forexample steam is obtained from ventsin the Earth’s surface which is used bygeothermal power stations to generateelectricity. Geothermal energy isconsidered a renewable naturalresource. It is used extensively in NewZealand and Iceland

gerrymander — the deliberateredrawing of political boundaries tomaximise an electoral advantage ofone party over another. This is a formof electoral bias

geyser — (or hot spring) a hot waterfountain that erupts intermittentlywith great force. ‘Old Faithful’ in theUSA is the best-known geyser; it eruptsevery three minutes sending a jet ofhot water as high as 60 metres into theair

ghats — the mountains to the east andwest of the Deccan plateau in centralIndia. The mountains are knownrespectively as the Eastern andWestern Ghats

ghetto — a small area dominated by aminority group

gibbers — these are small stones on thesurface of some Australian deserts.Deserts where these gibbers arewidespread are called gibber deserts –as opposed to sandy deserts (see reg;see figure 20)

giffen goods — giffen goods are oftenreferred to as inferior goods wherecommodities of a relatively low priceform a significant component of thediet and livelihood of low incomeearners

gigalitre — one thousand million litres(also written as GL)

gilgai — originally an Aboriginal word,‘gilgaay’ meaning waterhole. It is nowused to refer to terrain of low reliefmade up of small mounds resultingfrom the alternating periods ofexpansion and contraction followingwet and dry weather.

Gilgai are found typically in semi-aridareas where summer temperatures arehigh and rainfall variable. Gilgai relief can range from a fewcentimetres to several metres and upto 10 metres apart

glacial — a landscape occupied orformed by glaciers and glacialconditions (see figure 28)

glacial period — a period in Earthhistory that saw temperatures muchlower than present, as well as thedevelopment and growth of glaciersduring an ice age

glacial valley — a valley formed by thepower of a glacier (see figure 29colour, U-shaped valley)

glaciation — a process that sees theexpansion of glaciers and glacialconditions typified by cold conditions. The last glaciation (or glacial period)on Earth was during the Pleistoceneepoch. Within this last globalglaciation there have been manyglacial and interglacial periods. The last glacial period was at itscoldest at approximately 17,000 yearsB.P. When glaciation was widespreadespecially in the Northern Hemispherelarge icesheets covered much ofEurope and northern North America. Australia was limited to a small 50 km2

icecap on Mount Kosciuszkoglacier — the result of the accumulation

of snow and ice. Under its own weight,this ‘river of ice’ can move downslopealong a well-defined channel (seeglacial valley)

glei soil — soil that has developedunder wet or even saturatedconditions where the water table isclose to the surface. The soil or even ahorizon in that soil my take on agreyish-blue colour

global commons — see common(s)global economy — the increasingly

interconnected global system ofproduction and trade. Associated withthe global economy are the increasinglinkages between individual countriesas well as the rise of globalmanufacturing, marketing and finan-

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cing. The global economy has seen thedecline in the nation state being ableto operate in isolation

globalisation — a process of increasingintegration of economic, social andpolitical activity around the world. As aresult of a faster and more efficienttransport network and advancingcomputer technology, the individualnation state is becoming less of aforce on the global scene. An exampleof the globalisation process can beseen with the emergence, since the1970s, of global businesses in the formof transnational corporations and thepower they exert on domestic andforeign governments

global-local nexus — the connectionbetween global and local forceswhereby global forces are seen to bemore powerful and spatially importantwhereas local forces are relativelyweak and less geographically effective

global positioning system — a satellitenavigation system which is used todetermine positions in threedimensions (GPS)

global warming — a warming ofatmospheric temperatures during thetwentieth century. The cause of globalwarming has often been attributed tothe build up of carbon dioxide in theatmosphere from the burning of fossilfuels used for heating and as an energysource for transport and industry.There is the alternative view thatglobal warming is a natural process ofthe atmosphere as temperatures riseand fall within a glacial cycle

glossopteris — a fossil plant dating backto the late Paleozoic Era. It has beenfound widespread in South America,Africa, Australia, India and Antarcticaproviding further evidence supportingcontinental drift

gobar — a fog found on the upper NileRiver

Golden Triangle — that part ofnorthern Thailand, Burma and Laosknown for the production of opiumpoppies and the illicit trade in opium

Gondwana — also Gondwanaland; thename given to one of two landmasses

that made up the surface of the Earthapproximately 150 million years ago. As a result of plate tectonics Gond-wana split into the present-daySouthern Hemisphere continents ofAustralia, Antarctica, South America,Africa and Antarctica — as well as theland today known as India (seeLaurasia and Pangaea)

Goyder’s line — in 1870 the SouthAustralian Surveyor General G.M.Goyder suggested that the govern-ment of the day prohibit settlement inareas unsuited to agriculture. He stated that ‘nature’ had clearlyestablished a line beyond whichpermanent settlement must be givento the pastoral tenants rather than theagriculturalists. This line of demarcation betweenreliable rainfall in the south and where“drought prevails in the north”became known as Goyder’s Line. It extends in an arc in South Australiafrom Moonta on the York Peninsula inthe west, to Orroroo in the north, thento near Morgan in the southeast (seepastoralism)

GPS — see Global Positioning Systemgradational texture — in describing

soil texture, a soil with a gradationaltexture profile is one where thetexture grade gradually becomes finer(more clayey) with depth (see duplexsoil, uniform texture)

graded bedding — a characteristic ofsome sedimentary deposits whereparticles of different sizes have beensorted from coarse to fine particles.Typically the heavier coarse particlesare at the base of the deposit and thefiner particles are towards the top.

graded profile — as a river erodes,transports and deposits its load alongits length there may come a timewhere, at particular points along itscourse, erosion and deposition are inbalance – it is neither eroding ordepositing material. At this point, theriver is said to be ‘in grade.’ A river will erode down as well asdeposit material until this point is

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reached along its course. The point at which a river is ‘in grade’is typically at higher elevations inland. A cross section of these points from itsheadwaters to its mouth is known asits graded profile (see long profile,thalweg)

graded river — as a river flowsdownstream it erodes, transports anddeposits material until base level isreached. There will come time when the riverhas only enough energy to transportmaterial with no erosion. The river issaid to be in grade or to be a gradedriver

gradient — the slope of the land. Agradient of 1 in 10 means you have towalk 10 metres horizontally to go up(or down) 1 metre. Gradient can be obtained from atopographic map by looking at thecontour lines. The closer together the contour lines

the steeper the slope. The gradient canbe calculated using the formula:

Vertical rise (m) between the two points

Horizontal distance (m) between the twopoints

granite — a coarse-grained igneousrock. The large crystals in granite arethe result of the slow cooling ofmagma beneath the Earth’s surface

grassland — extensive areas of tallgrasses. They are almost treeless.Grasslands are a major world biomeand include the savannas of northernAustralia, the steppe of the Ukraine,the veldt of southern Africa and thepampas of Argentina

Great Artesian Basin — a vast areabeneath southwest Queensland andnorthwest New South Wales wheresedimentary rocks have stored enor-mous volumes of water over millionsof years.

Figure 30 � The Greenhouse Effect

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Some of this water is extracted viaartesian and sub-artesian wells forirrigation of crops like cotton and fordrinking by sheep and cattle

great circle route — a line drawn onthe surface of globe to show theshortest distance between two points.On a curved surface such as the Earththe shortest distance is not a straightline but rather a great circle

great soil group — a soil that hasworldwide distribution under similarclimatic and geomorphic conditions.Soils have traditionally been classifiedunder the headings of:

i) zonal – those formed underconditions of good drainage andresult from the long-term actionof climate and vegetation

ii) intrazonal – those developedunder conditions of very poordrainage (such as bogs) or onlimestones

iii) azonal – those that have no welldeveloped profile characteristicsdue either to having insufficienttime to develop or the slopes aretoo steep to allow profiledevelopment

Zonal soils of the great soil groupreflect the dominance of climate andvegetation. Examples of such soils are:

i) podsols – formed in cool humid

climates. The podzol is said toform on sandy parent material

ii) chernozems – formed in grasslandareas in the relatively drier (semiarid) climates of the mid-latitudes.Chernozems have developed deepdark, humus-rich profilesreflecting prolonged weathering

iii) latersols (lateritic soils) – formedin the warm, wet climates of thelow latitudes where hightemperatures and rainfall producedeep weathering and subsequentdeep soil profiles rich in iron andaluminium oxides

The use of great soil groups hascaused great confusion among soilscientists. This has resulted from therecognition from field surveys thatlocal soil forming factors such asslope, aspect and lithology may be justas, or even more, important inunderstanding soil development (seetexture contrast soil, zonal model ofsoil formation)

green politics — political decisionsbased on the understanding andrecognition of potential environ-mental impact. There is a focus on ‘green issues’ suchas the logging and deforestation, waterand atmospheric pollution as well asissues of urban planning andincreased public transport.

Global Ranking and Percentage of Global Emissions of Greenhouse Gases

Rank Country % Rank Country %

1 United States 20 11 Iraq 2

2 Russia 14 12 France 1.8

3 China 1 13 Canada 1.75

4 Japan 5.5 14 Mexico 1.6

5 Brazil 5 15 Poland 1.5

6 Germany 4 16 Australia 1.4

7 India 3.8 17 South Africa 1.2

8 United Kingdom 3 18 Spain 1.15

9 Indonesia 2.5 19 Venezuela 1

10 Italy 2.3 20 South Korea 0.99

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In Australia ‘The Greens’ are a politicalparty with a focus on green issues

greenbelt — an area around a town orcity that has been left as open space orparkland with the intention that this isnot to be built on

greenhouse effect — the effect of theatmosphere on incoming andoutgoing radiation (Figure 30). The atmosphere is made up of a rangeof gases such as oxygen, nitrogen,water vapour and carbon dioxide. The great bulk of radiation (short waveradiation) received from the Sunpasses through the atmosphere. The radiation that reaches the Earth’ssurface heats the land. The land re-radiates this heat back into theatmosphere but as long waveradiation. A large proportion of thisradiation is trapped in the atmosphereby various greenhouse gases such aswater vapour, carbon dioxide andmethane.This is the Natural Greenhouse Effect.Where the activities of people such asthe burning of fossil fuels and theclearing of forests increase thesegreenhouse gases this is known as theenhanced greenhouse effect andcontributes to global warming — thewarming that results from the additionof various gases by human activity tothe atmosphere

greenhouse gas — a gas in theatmosphere contributing to globalwarming. Carbon dioxide andmethane are greenhouse gases. Water vapour is the major greenhousegas allowing for an average surfaceglobal temperature of 15°C. Carbon Dioxide is the greenhouse gasbeing added to the atmosphere as aresult of the burning of fossil fuels andvegetation. Methane is the fastest growinggreenhouse gas in the atmosphere as aresult of activities such as the spread ofagriculture, and the melting of theArctic ice sheet and permafrost (seeGreenhouse Effect)

green revolution — a revolution inagriculture in the 1960s and 1970sespecially in such Asian countries asThailand and India. It saw increases infood production, in particular theyield of crops such as rice and wheat. This came about as a result of theintroduction of new high-yieldingvarieties of seed stock as well as theapplication of new production tech-niques and capital, such as fertilisers(see HYV)

green technology — technology thatpromotes the sustainable use ofnatural resources such as water,forests and energy and at the sametime having little or no adverse effecton the quality of that resource or theenvironment generally (see naturalresource)

Greenwich Meridian — see PrimeMeridian

Grevillea — a type of vegetation in theform of a shrub or small treecommonly referred to as spider flower

grey water — wastewater that can beused, not for drinking, but recycled fora range of purposes such as irrigationsystems on sporting fields and coolingin industry

grid — a system of vertical andhorizontal lines in many cases used todetermine the location of a feature eglines of latitude and longitude

grid pattern — often refers to aparticular street pattern. Streets arealigned at right angle to each otherespecially in areas of relatively flat landas opposed to winding roads typical ofmore hilly or undulating land

grid reference — a six figure mapreference used on a topographic mapeg 342658 (see figure 40)

gross domestic product — see GDPgroundwater — strictly all subsurface

water whether liquid, solid or a gas.Groundwater usually means that waterreceived from precipitation andstored beneath the surface below thesaturated zone of the water table.Groundwater however extends deeperthan this. Under the influence of

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gravity, groundwater moves slowly tofeed rivers eventually to drain to theoceans — this is called groundwaterrunoff

Group of 7 — see G7Group of 8 — see G8growth corridor — new areas of

housing, shops, manufacturing andcommunity facilities that follow roadsand natural features such as coastlinesand rivers. Growth corridors aretypically driven and encouraged byState government policies in Australia(see ribbon development)

guano — deposits of bird droppingsespecially on islands close to the coast.Such deposits can be used as fertiliserbecause of the high phosphoruscontent

guest worker — there are times whenthere are more opportunities for workthan there are workers available. In order to solve this labour shortage

governments allow international orinterstate workers to fill job vacanciesfor a particular period of time only —often under contract eg 3 years. Theseworkers are called guest workers

gully erosion — a type of acceleratedsoil erosion where deep scars (gullies)appear on the land leading to the lossof the total area of land available forcultivation and housing

guyot — a seamount with a flat top. Theorigin of these underwater mountainsin the ocean is unclear. Their flat topmay be the result of erosion duringtimes of much lower sea level but thisis not proven

gyre — the large-scale circulation ofwater in the world’s oceans. Gyresinvolve major ocean currents such asthe gyres off the east Australian coast;and the gyre associated with the NorthAtlantic Ocean

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ha ha — a trench, ratherthan a fence, acting as aboundary around anarea such as a zoo toallow the uninterruptedviews of onlookers

habitat — the area or environment inwhich a plant or animal lives

hachure — shading used on a map togive the impression of the shapeof the land such as the steepness oftopography

Hadley cell — part of the generalcirculation of the atmosphere. As air isheated at the equator air rises throughthe troposphere forming an area oflow pressure. At a particular altitude (ie at thetropopause approximately 8–10 km)the air moves to the poles. In theSouthern Hemisphere the air atapproximately 10 km altitude movessouth. As it is affected by the coriolis force theair tends to accumulate, then sink atlatitude 20°–30°S forming an area ofhigh pressure. These are the latitudesof many of the world’s deserts – eg theGreat Sandy Desert in Australia. Thereturn flow in the lower atmosphereback to the equator completes theHadley cell (see figure 26; latitude)

hail — solid precipitation which falls inthe form of ice particles especiallyfrom cumulonimbus clouds

half-life — the time taken for half of asubstance to decay. The term iscommonly used to describe the half-life of radioactive elements such asuranium. For example an element with a half lifeof 1000 years decays by half after 1000years; after another 1000 years half ofwhat remains decays; after another1000 years half of this decays

halo — a phenomenon in theatmosphere where a circle or haloappears around the Sun. The halo isthe result of light from the sun beingrefracted by ice crystals in very highclouds such as cirrus clouds

halophyte — a plant adapted to soilscontaining sodium chloride (salt)

halosere — a plant succession that hasevolved in relatively salty (or saline)conditions

hamada — in a desert the surface ismainly bedrock (rather than the morerecognisable sandy deserts)

hamburger connection — the destruc-tion of rainforest in order to producecheap hamburger beef for the NorthAmerican market

hamlet — a very small settlementconsisting of a few buildings in a ruralarea. The term is not very usefulbecause it refers to any settlement toosmall to be called a village

Han — the main ethnic group in Chinamaking up about 90% of thepopulation

hanging valley — during glacialperiods, glaciers grow and erode deepvalleys. Smaller glaciers may join themfrom the sides but, being small do noterode as deeply as the large glacierthey join. Since the glaciers havemelted and retreated up their valleysthe small tributary glacial valleys‘hang’ over the larger valley they werefeeding into. These hanging valleys areoften the sites of waterfalls in formerglaciated environments (see figure 28)

hardpan — a hard or brittle layer (orhorizon) within a soil profile. A hardpan develops as a result of theprocesses of eluviation and illuv-iation. Water/minerals/soil particlesaccumulate within the profile andharden to form a relatively dense or

H


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hard area. Hardpans are often foundin soil profiles developed on sanddunes in soils called podsols (see alsoindurated (or induration)

harmattan — the name given by localpeople to refer to the dry dusty windsin West Africa

headwaters — where the river starts.The headwaters of most rivers arefound in upland or mountain areasand eventually flow to the river mouthat the sea

heath — a vegetation communityconsisting of low dense shrubs (eg 1–2metres high) typically growing on theinfertile, sandy, acid soils of exposedplateau surfaces such as aroundSydney, NSW and Perth, WA Australia.

heat equator — a line joining thehottest places around the world.Isotherms join places of equaltemperatures. The heat equator joinshottest places – these are notnecessarily the same temperature.Although this would be expected to bealong the equator, because of theuneven distribution of land andoceans this line wanders north andsouth of the equator – hotter areas areover the land and cooler areas are overthe oceans

heat island — the building materials ofmajor settlements are made up ofbricks, concrete, asphalt. Thesematerials tend to absorb heat quicklyduring the day and retain it at night.However the surrounding countrysidereleases heat more quickly especiallyat night so tends to be cooler than theurban area.The warmer urban area might be1–3°C warmer than the surroundingarea – it stands out as an island of heator a heat island. This is typical of mosturban areas. The microclimate of thisurban heat island is very different fromthe surrounding hinterland. For example besides being warmerthey tend to be:

• less windy; although some areasare very windy because of the windtunnels created by some adjacentbuildings,

• cloudier as a result of theconvection over the urban areaand therefore wetter and morepolluted from the exhausts ofmotor vehicles and effluent fromindustry

heavy industry — manufacturing thatinvolves both the processing of largevolumes of heavy raw materials (suchas iron ore, coal or steel products) aswell as the production of high volume,high weight finished goods (such as aniron and steel works or car manu-facturing). Heavy industry has become increas-ingly automated with the use ofcomputer technology replacing labour traditionally provided by people (see automation, light industry,manufacturing,)

heavy metal — a metallic element suchas lead, cadmium, aluminium andmercury; these are generally toxiceven in low concentration. In mammals they can accumulate intissue matter ultimately causing death(as such they are bioaccumulative)

hectare — an area of 10,000 squaremetres in size (100 m x 100 m)

hectolitre — one hundred litreshectopascal (hPa) — the unit used as a

measure of air pressure at a point overthe surface of the Earth. Millibars werepreviously used

helicoidal flow — an unstable flowregime in a fluid such as a river wherecross currents interact with the mainchannel flow setting up a spiralmotion or eddy within the flow. Thespiral motion is elongated in thedirection of stream flow. In a river thespiral motion sets up a meanderingflow with the outside of the meanderbend eroded while the inside of themeander bends include point bardeposits indicating deposition. Asimilar process occurs in winds in theformation of desert longitudinal sanddunes

helictite — a speleothem that appears todefy the law of gravity, growing in anydirection such as horizontally out of acave wall. Growth may change

aryewhy

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direction as crystal growth changesabruptly but most growth follows acurved path (see stalactite andstalagmite)

hemisphere — in Geography areasnorth of the equator are in theNorthern Hemisphere; those south ofthe equator are in the SouthernHemisphere

herbivore — a plant-eating animal suchas a Koala (see carnivore andomnivore)

heritage value — the aesthetic, historic,social or scientific significance ofplaces, objects (eg a house) or evenlanguages to the community today orto future generations

Herodotus — a Greek geographer/historian around 450 BC who was oneof the first people to recogniserelationships and vastness of timeinvolved in Earth surface processes.On travelling through the lower NileRiver valley he recognised the effectsof individual floods in laying sedimenton the Nile delta. He then concludedthat the delta must be ‘very old’ if oneflood lays down a single layer ofsediment

heterotroph — a term used to refer toorganisms that do not produce theirown food but consume otherorganisms such as vegetation to gainnutrients and energy. Examplesinclude lions, kangaroos and deer.Heterotrophs include the herbivore,carnivore and omnivore – theconsumers

hibernation — a dormant state of ananimal in winter where its bodytemperature is very much reduced sothat its metabolism is very muchreduced (see estivation)

high income economy — thosecountries with a GDP per capita greaterthan $9500. Australia, USA and Franceare examples

high order goods — in the study ofpopulation and settlement or eveneconomic geography a high ordergood is one which is relativelyexpensive and one in which people

will travel a relatively long distance toobtain. For example people will travela long distance to purchase a car oreven furniture compared to anewspaper (see low order goods)

high pressure cell — an area of highpressure consisting of closed isobars.In a high pressure cell the value of theisobars increase towards the centre (iethe pressure increases). In theSouthern Hemisphere winds blow inan anticlockwise direction around ahigh pressure cell (see air press, lowpressure cell, figure 55)

hinterland — commonly used to referto the area around a city or otherurban area. The hinterland is linked tothe urban area it surrounds such as bytransport, trade and communicationlinks. For example the hinterland mayprovide food via market gardenswhereas the urban area providesemployment and goods and services –both areas linked by road, rail andcomputer technology

hoar frost — a deposit of ice having acrystalline appearance and forming attemperatures below 0ºC

holding — land legally held by alandowner or tenant eg a one hectareholding

Holocene — a subdivision of the Quaternary Period following thePleistocene. The Pleistocene wasmarked by many fluctuations in temp-erature typified by glacial periods.By 10,000 years ago temperatureswarmed close to those of today. This signaled the start of theHolocene. Some people believe thatwe are still in the Pleistocene Periodand that the present climate should bedescribed as an interglacial within thePleistocene ice age (see figure 27)

homo sapiens — the modern humanrace

honeycomb weathering — the break-down of rock material by the action ofsalt crystallisation producing ahoneycomb pattern in the rockface(figure 31 colour)

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horizon — (see soil horizon) horizontal integration — a type of

business expansion where a businessexpands into a similar line of businessin the production process; forexample a food processing businessexpanding by taking over another foodprocessing business; a retail chain mayexpand by taking over another retailchain (see vertical integration)

horn — a landform typical of glacialenvironments where 3 or 4 cirqueshave met after a long period ofweathering at the top of a mountain.Where the ridges associated with thesecirques meet a sharp peak or horn isformed. The Matterhorn in Switzerlandis an example (see figure 28)

horticulture — the growing of flowers,fruit and vegetables. Horticulture is anintensive form of agriculture, typicallyon small areas of land and using highinputs of capital such as machineryand fertilisers. The growing of tomatoes ingreenhouses especially in winter is anexample of horticulture (see intensivefarming,/agriculture/land use)

Horton overland flow — is defined asoverland flow that occurs whenrainfall intensity is so great that not allthe water can infiltrate. This type ofoverland flow is common in semi-aridenvironments but relatively rare inhumid-temperate regions where therole of vegetation has a critical role inthis distinction (see infiltration,runoff)

hospitality industry — that part of theeconomy concerned with providingservices, such as entertainment, forguests

hot spot — an area where magma hasaccumulated within the Earth’s crustor upper mantle. The magma mayfind its way to the surface to form avolcano as a plate moves across it. An example of this is Hawaii today.Over the past 40 million years asAustralia has drifted north it haspassed over a hot spot, now located inthe Southern Ocean, with volcanoesformed initially in what is now

northeast Queensland extendingsouth into what is now Victoria (seecontinental drift, volcano)

Hoyt, H. — in 1939 Homer Hoyt prop-osed a model of urban structure. Hissector model suggested that areas ofhighest rent tended to be alongsidethe main lines of communication andthat that cities grow in a series ofwedges. He built on the earlierconcentric zone model of E.W. Burgess(see Burgess, E.W., figure 58)

human development index — astatistical measure that gives anindication of the quality of life ofpeople in an area such as a countrybased on factors including education,life expectancy, food intake andpolitical freedom. The index rangesfrom 0–100 with greater than 80indicating a high level of development(eg Australia, France and Canada) andless than 50 indicating a low level ofdevelopment (eg Laos, Togo andNicaragua)

human geography — a branch ofGeography concerned with theprocesses and patterns created bypeople on the Earth’s surface; forexample population growth andmovement, employment, city or urbandynamics as well as land use and landuse change. Human geography duringthe last quarter of the 20th centurybecame immersed in lengthy debatesconcerning the underlyingphilosophies of Geography. Some geographers were attracted toMarxism and others to philosophicalcurrents that have examined thenature of power, knowledge andrepresentation. A focus has been placed on the eclipseof modernism by a post-modern ageand artistic representation togetherwith its expression in complex formsof post-structural discourse. Geography has come to the fore inboth contemporary social science andcultural studies (see post-modernism,post-structuralism)

humanism — the philosophy or viewthat emphasises the human values,

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humanity or even the quality of humanlives in an area of study

Humboldt current — an ocean currentcarrying cold water northwards alongthe coasts of Chile and Peru in SouthAmerica. This is an important currenteconomically to the fishing industriesof these countries in that it brings coldAntarctic waters and deep sea fish tothe surface

humic acid — a weak acid produced asa result of the breakdown ordecomposition of organic matter (seehumus). Humic acid moves in solution typicallywithin soil material. Humic acid is animportant agent in the chemicalweathering of a wide range ofminerals in rocks – eg limestone andsandstone (see humus)

humidity — see relative humidityhumus — partially or completely

decomposed organic material such asvegetation, in the soil. Humus (orhumic material) provides nutrients tothe soil later to be taken up byvegetation and can often be seen in

the upper horizon of soils (see soilhorizon)

Huon Pine — a descendent of theconifers that dominated theGondwana forest approximately 100mya. The Huon Pine thrives inSouthwest Tasmania – the oldestknown living tree in Australia(2000–3000 years old). Its distribution and numbers havebeen severely diminished as a result oflogging in the 19th and 20th centuries

hurricane — an area of intense low airpressure common in the CaribbeanSea and Gulf of Mexico, south of theUnited States bringing strong windsand torrential rainfall. These types ofintense low pressure systems arecalled tropical cyclones in theAustralian/Indonesian region andtyphoons in Asia (see low pressurecell)

Hutton, James — a Scottish physicist(1726–1797). After extensive fieldexperience he came to the conclusionthat no more than present dayprocesses were needed to explain the

Figure 32 � The Hydrologic Cycle

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past. The phrase ‘the present is the keyto the past’ was coined and summedup by the term ‘uniformitarianism.’ However because of our knowledge ofpast environments and theirassociated processes (for exampleprevious glacial processes in presenthumid or even arid environments) abetter phrase might be that ‘the past isthe key to the present.’ Similarly Hutton’s ideas have beenmodified with the increasingacceptance of catastrophe theory (orcatastrophism) – for example theimpact of earthquakes, tropicalcyclones on landscape evolution

hybrid — an organism that is producedby parents of a different species. Theprocess of hybridisation often leads tosterile offspring

hydration — the process whereby amineral (not containing a watermolecule) takes up water from adifferent mineral leading to the

breakdown or disintegration of therock

hydraulic action — the pressureexerted by the compression of a fluid.The action of waves crashing intocracks in a sea cliff wall exerts pressureand eventually leads the breakdown ofthe rock and collapse of part of the seacliff. Similarly the action of running waterin a river exerts hydraulic pressure onthe bed and sides of the rivereventually deepening and wideningthe river

hydrocarbon — chemical compoundscontaining hydrogen and carbon. Theterm hydrocarbon is commonly usedfor the variety of fossil fuels such asoil, coal, natural gas and oil shale

hydroelectric power — energy, such aselectricity, generated from the powerof running water. The SnowyMountains Hydro-Electric Scheme inAustralia generates hydroelectric

Volumes and Transfers of Water on a Global Scale

VOLUME TRANSFERSof water /km3 of water /km3

Atmosphere 13,000 Land evaporation 70,000

Inland water freshwater lakes 100,000 precipitation 110,000

saline lakes 105,000 Oceans evaporation 430,000and inland seas

rivers 1700* precipitation 390,000

soil moisture 70,000 Runoff ** surface 39,000

groundwater 8,200,000 groundwater 1000

ice caps 27,500,000 Winds ** 40,000and glaciers

biota 1100

Subtotal (land) 35,900,000

Oceans 1,350,000,000

Total � 1,385,900,000all water

* estimated at any one moment** these are the same quantities transferring water between the ocean and the land andback againSwamp water and water held in permafrost are incorporated in above figures.

Data collated from a range of sources: World Resources Institute; PH. Gleick ed, Water incrisis: a guide to the world�s freshwater resources, Oxford University Press, 1993

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power as water from rivers such as theMurray River is diverted and used toflow over turbines to generateelectricity. This electricity istransported by cables to provideenergy for many communities

hydrograph — a diagram showing thechanging stream discharge usuallyrelated to changes in rainfall amounts.A hydrograph record changes in waterflow as a result of increased rainfall inthe headwaters of a catchment area

hydrolysis — a form of chemicalweathering; the breakdown of organiccompounds through their interactionwith water

hydrologic cycle — the cycling ortransfer of water between variousstorages such as oceans, lakes and theatmosphere. This occurs through avariety of processes includingevaporation, condensation, precip-itation and runoff within thebiophysical environment (see figure 32).Solar energy drives the hydrologiccycle. Water is evaporated from theoceans as well as the land. As air risesit cools and condenses, may reach dewpoint and then precipitate. Precipitation, reaching the surface canbe lost in the form of evaporation orfrom vegetation in the form ofevapotranspiration. However somemay find its way to the surface of theland, to flow across the surface asrunoff. Some water will infiltrate intosoils to form groundwater.Groundwater runoff will eventuallyflow to a river. Surface runoff in the form of riversmay eventually flow to the sea. The hydologic cycle continues.The processes and quantities involvedvary greatly around the world such asin desert and rainforest areas.Estimates of global volumes of waterstored and transferred vary. Howeverapproximate values can be seen in thetable above (see condensation,infiltration)

hydrophyte — a plant adapted topermanently wet conditions. Theseplants have some parts submerged

under the water that survive evenwhen parts above water die back

hydroponics — the cultivation of cropsin the absence of soil. Crops are fed viachemicals and organic elements in asolution of water

hydrosere — a plant succession in a wetenvironment. A mangrove communityhas developed and evolved in wetconditions especially along coastlinesand at the river mouths. Hydroseres can also be seen to haveculminated as inland swamps wherewater remains on the surface due tolocal biophysical conditions. Such conditions include clay soils notallowing water to drain away and evenin areas of internal drainage wherewater flows inland to a common lowpoint (eg Macquarie Marshes, NSW,Australia)

hydrosphere — the sphere of the Earthdominated by water. This includesthe oceans, rivers, lakes andgroundwater in liquid, solid andgaseous form. Within the hydrosphere water isstored in locations such as the oceans(liquid) and the atmosphere (gas) andthe ice caps (solid). Water istransferred from one place on theEarth to another place in its differentforms. This is the hydrologic cycle.

• About 70% of the Earth’s surfaceis covered by water

• 97.3% of all water is found in theoceans

• Each year approximately 500,000km3 of water is evaporated fromthe Earth’s surface

• 430,000 km3 from the oceansand 70,000 km3 from the land

• Each year approximately 500,000km3 precipitates on to the Earth’ssurface, 390,000 km3 over theoceans and 110,000 km3 on tothe land

• 40,000 km3 of the waterprecipitates over the land andreturns to the sea as runoff

• 40,000 km3 is returned to theland as water vapour via winds

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hygrometer — an instrument formeasuring relative humidity of theatmosphere (see psychrometer)

hypermarket — a superstore of at least50,000 ft2 (4600m2) of sales area

hyper-reality — a condition where thefake feels more real than the original,for example Main Street USA inDisneyland or the theme parktechniques used in shopping malls

hypsometric curve — or hypsometricgraph, a curve on a graph to show theproportion of land above and below adatum such as sea level

hythergraph — a type of graph, whichhas monthly temperatures, plottedagainst monthly precipitation

HYV — high yielding variety, eg rice,producing much higher yields thannormal varieties (see greenrevolution)

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ice age — a period in theearth’s history whentemperatures were muchlower than present andvast ice sheets coveredmuch of the Northern

Hemisphere continents in the mid andhigh latitudes.The most recent ice age occurredduring the Quaternary Period. Most of this Period is known as thePleistocene Epoch (commonly calledthe Pleistocene). During the Pleisto-cene temperatures varied by as muchas 10ºC. The cold phases are calledglacial periods when ice coverexpanded. These were separated by warmerinterglacial periods. The coldestperiod of the last glacial was about17,000 years ago when sea levels wereup to 200 metres lower than present.The last glacial period ended about10,000 years ago after which glaciersretreated to higher altitudes, sea levelsrose, and temperatures began toapproach what they are like today (seefigure 27)

igneous rock — a rock formed deepbeneath the earth’s surface from theslow cooling of magma. Granite is anexample of an igneous rock

Iguaçu Falls — a spectacular series ofwaterfalls (cataracts) over 3 km long.The waterfalls form part of a worldheritage site on the Argentina-Brazilborder (see world heritage list/site)

illuviation — the deposition of soilparticles within a soil profile –sometimes forming a distinctive layer(or soil horizon) recognised by acolour change or change in hardness(see eluviation, hardpan)

ILO — International Labour Organis-ation

IMF — International Monetary Fund. A fund to which developed countriescontribute. The money is then given tospecific projects that the World Bankbelieves would benefit developingcountries

immigration — the movement ofpeople into an area. Internationalmigration involves people movingfrom one country to another. The movement of people into Aust-ralia from Canada is an example ofimmigration (see emigration)

immigrant — a person who moves orhas moved into another country. For example an immigrant is a personwho has moved into Australia fromFrance

imperialism — a term used to describethe invasion and subsequent controlof one country by another country. In many instances the term hasnegative connotations following theearly colonisation and control (inmany cases oppression) of developingcountries of Africa, Asia and SouthAmerica during the 1700s and 1800s. The country taken over has a greatdeal of dependence on the colonisingcountry. These colonial powers (orimperialists) have sort to expandterritory or exploit available naturalresources. However the political system of thisimperialist state is very unstable as aresult of conflict between power blocsas well as the indigenous community.This instability was seen especiallyduring the 20th century as indigenouspower saw independence movementsflourish – in many instances throughviolent revolution. Vietnam was acountry that had a a great deal ofdependence on France as thecolonising power

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impermeable/impervious — a condit-ion of material such as soil or rock thatdoes not allow, under normalconditions, the movement water; forexample the texture or structure of thesoil or rock may prevent watermovement. Under some conditionsrock may have an impervious texturethat does not allow the movement ofwater through it but the structure ofthe rock with fractures may mean therock is permeable (see permeability)

incised meander — a meandering rivermay flow slowly to the sea flanked oneither side by a wide floodplain. Forsome reason the river experiencesrejuvenation – it gains more energy.This may result from sea level becominglower or the land through which it flowsrises. Since the river now has moreenergy it cuts down (or incises into theland) forming deeper and steeperwalled valleys. These are called incisedmeanders (see meander)

income elasticity — a measure ofpeople’s demand for products/servicesas their income levels change

index numbers — numbers or indicesused to show relative change in a set ofstatistics rather than the actual numberinvolved in the change. The value of aparticular year (the base year) is chosen.How other values vary from this value interms of percentage difference is thendetermined. For example suppose in1985 the population of an area was1200. In this case, 1985 as the base yearis given as the index number of 100. Ifan array of data indicates that 1990 hasa population of 1320 the year 1990 isgiven an index number of 110indicating that 1990 has a population10% more than the 1985 figure. Anindex number of 90 indicates that thepopulation is 90% of (or 10% less thanthe 1985 figure)

indigenous — native to an area; notintroduced (see exotic)

indigenous people — original inhab-itants of the land (also known asaborigines). Indigenous people include:

• Koori — Australia

• Maori — New Zealand• Inuit — Greenland, northern

Canada, Alaska, Aleutian Islands• Yanomami — within various parts of

the Amazon Basin• Maasai — East Africa eg Kenya• Ainu — Hokkaido, Japan• Penan — East Malaysia (Sarawak)

(see page 90)indurated (or induration) — the

hardening of materials such as soil as aresult of pressure from overlyingmaterials and cementation as a resultof the addition of types of minerals. Insoils such as podsols an induratedlayer (or horizon) may form as a resultof the accumulation of iron minerals.This is called a hardpan (seeeluviation, illuviation)

industrial agriculture — a type ofcommercial agriculture where cropsundergo a number of mechanicalprocesses (eg plantation crops suchas coffee and rubber)

industrial inertia — the state of a firmwhereby it stays in one location whenthe initial reason for that location hasdisappeared, or a firm fails to adoptnew strategies/technologies whichmay be to its benefit

industrialisation — the growth inmanufacturing / industrial activity in aregion, a country or the world. The process of industrialisation canbegin from a largely agricultural basewhere there is an increasing use ofmachinery in factories; industrial-isation can also be seen with analready industrialised countryadopting more advanced forms oftechnology such as computer tech-nology. Industrialisation is commonlyassociated with the growth of theservice sector as labour-savingtechniques are used such as the use ofrobotics – less labour is often requiredin manufacturing with a shift in labourgrowth to the provision of servicessuch as within the finance sector andeducation

infant mortality rate — the number ofdeaths of infants in the first year of lifeper 1000 births. For example between

aryewhy

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1990 and 1995 the infant mortalityrate in Mali (Africa) was 159 whereasin Australia it was 7

infiltration — the downward move-ment of water through the Earth’ssurface. The rate of infiltrationdepends on such factors as thevegetation cover, slope of the land,soil type and bedrock (see figure 32)

informal sector — that part of theeconomy in which employment isofficially less than full time; this

includes the self-employed and part-time workers. The informal sector is relatively largein developing countries and has beenexpanding in developed countries aspart-time workers are increasinglyreplacing full-time workers. The informal sector includes thoseillegal occupations as well as thoseoccupations that do not pay taxes forwork completed (see formal sector)

Some Indigenous Peoples of the WorldREGION NAME

Canada and USA Inuit (northern Canada/Alaska); Haida, Tlingit, Kwakiutl, Bella Coola,Tsimshian, Nootka (Canadian west coast); Cree, Meti, Chipewyan,Blackfoot, Dene (central Canada); Innu, Cree (eastern Canada);Haudenosaunee (Canada/USA border); Nez Percy (NW USA), Navajo,Uti, Pueblo including Hopi, Keres, Zuni, Dine (SW USA); Crow,Cheyenne, Arapaho, Pawnee, Comanche, Oglala Sioux, Shoshone (theplains of the USA)

Central America Mayan descendants � Lacandon, Yucatec; Aztec descendants �Huichol, Tarahumara, Nahua, Zapotec (Mexico); Maya (Guatemala),Miskito, Sumu, Rama, (Nicaragua); Lenca, Pipile (El Salvador); Kuna,Guaymi (Panama)

Arctic and Europe Inuit (Arctic); Aleut (Alaska); Saami (Norway, Sweden, Finland andRussia)

South America Quechua, Aymara (highland Peru, Bolivia and Ecuador); Mapuche(Argentina and Chile); Tukano, Xavante, Yanomami, Parakana, Kayapo,Makuxi (Amazon Basin, Brazil); Amarakaeri, Amuesha, Tukano, Panare,Sanema, Shuar, QuichuA, Ufaina (Amazon Basin, Ecuador, Bolivia,Peru, Colombia, Venezuela)

East Asia and Russia Tibetan, Uighur (China); Mongolian (Mongolia); Ainu (Japan); Yuit,Kazakh, Saami, Chukchi, Nemet (Russia)

Africa Tuarg, Fulani (Sahara, Sahel); Dinka, Nuer, Shilluk (southernSudan);San Bushmen (Angola, Botswana, Namibia); Maasai(Kenya,Tanzania); Oromo, Somali, Tigrayan, Eritrean (Ethiopia); Mbuti, Efe,Lese (Zaire, Cameroon, Central African Republic)

South Asia Naga, Santal, Gond, Kameng, Lohit, Dandami (India); Pathan(Afghanistan, Pakistan); Vedda (Sri lanka) Chittagong Hill Tract Peoples(Bangladesh);

Southeast Asia Karen, Kachin, Shan, Chin, (Burma); Karen, Hmong, Lisu (Thailand);Penan, Kayan, Iban (Malaysia); Kalinga, Ifugao, Hanunoo, Bontoc,Bangsa Moro (Philippines); Dayak (Indonesia � Kalimantan); WestPapuan including Asmat, Dani (West Papua); Mae-Enga, Dani,Tsembaga (Papua New Guinea)

Oceania Aborigines (Australia); Maoris (New Zealand); Kanak, Hawaiian,Tahitian, Chamorro (Pacific Islands)

Source: Burger, J, The Gaia Atlas of First Peoples, 1991, p18-19

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informational city — a node forinformation flows through hightechnology media where large sectionsof the labour force work in suchoccupations as banking, insurance andlegal services

infrastructure — the materials in placeto support the effective functioning ofa community. Infrastructure includeswater and power supplies, road andrail transport networks as well ascommunication systems such astelephone and computer informationtransfers

inselberg — a large isolated hillsurrounded by an eroding plain. Theyrise above the general level of theplain because they tend to be of amore resistant rock type than the plainor are the remains of a long period ofbackwearing across the plain with onlythe inselberg remaining. Inselbergsoccur in such rock types as sandstoneand granite. Uluru (Ayers Rock) is anexample of an inselberg

in situ — a term associated with a rock,soil or fossil being located in itsoriginal place of deposition orformation. For example “the soilmaterial has formed in situ”; ie is thesoil material has formed at this placeand has not been transported fromelsewhere by wind or water

insolation — radiation received fromthe Sun. INcoming SOLar radiATION

insolation weathering — the disinteg-ration of rock in response to heatingand cooling as it expands during theheat of the day and contracts duringthe cold of the night (see physicalweathering)

intensive farming/agriculture/landuse — land use, agriculture or farmingrequiring a high input of capital, suchas machinery and fertilisers, within arelatively small area of land. Dairy industry is an example ofintensive agriculture that uses a highinput of capital (expensivecomputerised machinery), moderntechnology (scientific breedingtechniques) and a small area of land.This compares to the more extensive

forms of agriculture such as beef cattlegrazing that requires very large areasof land (see extensive farming/agric-ulture/land use)

interculture — see intertillageINTERFET — the international force in

East Timor. After East Timor’s vote forindependence from Indonesia, in1999, the UN Security Councilimplemented a peace-keeping forcefollowing much civil disturbance. INTERFET forces included Australia(the largest component with over 400troops), USA, Britain, Canada,Philippines, France Thailand and NewZealand

interfluve — the ridge separating tworivers. The interfluve marks theboundary of the catchment of a river(see catchment area)

intergenerational equity — in terms ofecological sustainability this is bestexpressed in Principle 3 of the RioDeclaration: The right to develop-ment must be fulfilled so as toequitably meet developmental andenvironmental needs of present andfuture generations (see intragen-erational equity)

interglacial period — a warm periodbetween ice ages. During thePleistocene ice age the cold glacialswere separated by warmerinterglacials. The present Holocene inwhich we live is an interglacial

interlocking spurs — topographicfeatures produced as a river follows awinding or meandering course in itsvalley (Figure 33 colour). As a result of erosion, the land slopesrelatively gently from the interfluve tothe inside of a meander bend whilethe outside of the meander bend tendsto have a much steeper slope. This is due to undercutting of thisslope by the river. As the rivermeanders in its valley, avoiding highground or resistant rock, a series ofthese spurs can be seen interruptingthe view up and downstream

intermittent stream — in terms ofstreams, stream that flow only part of

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the year, for example immediatelyafter rain

internal drainage — most rivers flow tothe sea from higher land. Howeverthere are places where rivers flow to alow point in the land such as a lake.Lake Eyre in South Australia is an areaof internal drainage. Here rivers suchas the Diamantina River and CoopersCreek flow into the lake (at 10 metresbelow sea level)

International Date Line — 180° long-itude

international division of labour — aterm used to describe the globaldivision of production betweenvarious countries. This tends to lead tocountries or regions specialising in aparticular type of production or stagein the production process. Suchspecialisation of production is largelyinfluenced by the power and decision-making of large corporations

International Geophysical Year —during a 30 month period – July 1957to December 1959 – over 70 nationsundertook a program of cooperativeresearch with a focus on the Earth andits environmental systems. Out of theIGY came the seeds for thedevelopment of the Antarctic Treaty

International Law of the Sea — firstdrafted in 1982 this internationaltreaty establishes national sovereigntyover marine resources lying withincoastal waters. Beyond the immediatecoastal waters the treaty identifies anExclusive Economic Zone – a 200nautical mile limit that gives themaritime nation the initial right toresources (eg fish stocks) within thiszone

International Monetary Fund — anagency of the United Nations thatprovides funding especially todeveloping countries in short termfinancial crisis

International Union for theConservation of Nature — see IUCNand World Conservation Union

intertidal — between the low and hightide marks (see tides)

intertillage — also called interculturethis refers to the practice of growingtwo or more crops on the one area ofland at the same time. Howeverplanting and harvesting are timed sothat such activities do not necessarilyfall at the same time

intertropical convergence zone — anarea of low pressure around the Earthlocated near the equator. The ITCZ ischaracterised by high humidity andhigh rainfall. The northeast and southeast tradewinds blow towards the low pressurearea of the equator. Convergence anduplift leads to heavy rainfall. The ITCZis not in a uniform location around theworld. It tends to meander (or wander) northand south of the equator extendingfurther north and south where landoccurs because of the greater heatingcapacity (and therefore convection) inthese areas. Similarly the ITCZ movesslightly north and south of the equatorwith the seasons. In the Southern Hemisphere summerthe ITCZ moves to around latitude5–10°S while in the NorthernHemisphere summers it moves toapproximately latitude 10–15°N. In thisway the ITCZ can be experienced withthe onset of the Monsoons (eg in theSouthern Hemisphere’s summer overnorthern Australia; and in theNorthern Hemisphere’s summer oversouth and Southeast Asia)

intervisibility — the ability to see anobject between two points such as ona cross section. If for example, on across section you can draw ahorizontal line between two pointswithout the line touching the crosssection drawn, then in real life youwould be able to see one point fromthe other — there is clear visibilitybetween the two points

intragenerational equity — when usedin terms of ecological sustainabilitythis means fairness and justice inresource use for all people of aparticular generation (see intergener-ational equity)

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intrazonal soil — well-developed, ormature soils, that reflect the signif-icance of local soil-forming factorssuch as parent material, slope,

drainage and vegetation – rather thanclimate as with zonal soils. Examplesinclude saline soils in poorly-drainedarid or coast areas and the bog soils

Figure 34 � The distribution of island arcs in the Pacific Basin and a cross section across an island arc

Source: C. Ollier, Volcanoes, Australian National University Press 1969 pp144-145

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reflecting the accu-mulation ofdecaying vegetation or peat in swampenvironments (see bedrock)

intrusion — the name given to theprocess whereby magma within theearth invades existing rock. Themagma associated with the intrusionsolidifies below the Earth’s crust andbecomes what is called intrusive rockeg granite (see extrusion)

inundation — the flooding of an areasuch as a river breaking its banks andflooding (or inundating) a town. Afterheavy rainfall rapid runoff acrossslopes can lead to rivers rising quickly.The river may overflow its banks andinundate the area covered by itsfloodplain

invasion and succession — i) themovement of people from one area toanother replacing a pre-existingpopulation. One group of people, for example aparticular age group, ethnic group orreligious group may move into aresidential area and over time, replacean existing group. This tends to occur over a long periodof time such as 10, 20 or 30 years (seegentrification); ii) the process of thegradual invasion and eventual plantsuccession by a new plant community;for example a small shrub communitybeing replaced over time by a tallertree community (see plant succession,sere)

inversion — a condition of theatmosphere where the temperatureeither increases with height or isconstant over a specific given distance(eg 10 m, 100 m, 1 km). Temperatures typically decrease withheight allowing warmer less dense airto rise through it. In some circumstances the temp-erature change is inverted where alayer of cold air lies beneath warm air. In this case air is trapped in lowerlayers – as seen in times of fog close tothe ground and pollution trappedabove cities unable to ‘break through’the inversion (see environmental lapserate, adiabatic lapse rate)

IPCC — Intergovernmental Panel onClimate Change

irrigation — the addition of water to anarea over and above normal amountseg additional water added to crops

irrigation salinity — a type of secon-dary salinity also known as wetlandsalinity; salinity due to excessiveirrigation. Under normal conditions the watertable is deep below the surface (eg 3metres). In many semi-arid areas, suchas southern NSW and NW Victoria(Australia), Israel and SW USA, peoplehave introduced types of agriculturesuch as rice farming. These activities require a large input ofwater via irrigation. By adding water tothe land the water table rises to thesurface bringing with it the naturalsalts in the soil. These salts are then concentrated inthe water. When used by farmersdownstream who repeat this processthe water becomes very saline (saltierand saltier) contributing to risingproduction costs and reduced cropyields (see dryland salinity)

island arc — a line of volcanic islandsarranged in an arc reflecting the shapeof the ocean trench beneath them(Figure 34). Subduction has occurred with islandsthe result of volcanic extrusion. TheIslands of Indonesia and the AleutianIslands are examples

isobar — lines joining places of equalair pressure shown in figure 55 (seehectopascals)

isobath — lines joining places on theseabed of equal depth (see contourline)

isodemographic map — a type of mapdrawn that shows a country’s size inproportion to its population

isodapane — in economic geography aline joining places of equal totaltransport costs. The calculation ofthese lines provides a firm withinformation on total productions costsand can act as a guide to locating afirm in a particular area

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isohyet — an isoline which joins placesof equal precipitation

isoline — a line that joins places ofequal quantity eg contour line andisohyet

isopleth — any line that represents aparticular quantity where everythingon that line represents the samequantity. A contour line, an isobar andan isohyet are isopleths

isostacy — the mechanism whereby theEarth’s surface rises or subsides as aresult of the different weight, ordensity, between two bodies. The less dense materials that make upthe continental crust ‘float’ on thedenser mantle below. The same process explains isostaticadjustment during the last glacialperiod where the Laurentide ice sheetin North America, and theScandinavian ice sheet in Europeweighed the continents down andforced much land below sea level. At the end of the glacial period the icesheet melted, the weight of the ice wasrelieved so the land rose slowly back

up to adjust to the shifting weight.This isostatic rebound is still occurringin northern Europe today

isotherm — isoline which joins placesof equal temperature

isotropic surface — a surface such asland which has uniform characteristicsin all directions such as flat land andthe uniform distribution of naturalresources. Isotropic surfaces areassumed in many location theories ofgeographic phenomena. This includesaccounting for the distribution ofsettlements in W. Christaller’s centralplace theory (see Christaller, W.)

isthmus — a narrow strip of land withwater on both sides connecting twopieces of land eg Panama Canal

ITCZ — see intertropical convergencezone

IUCN — International Union for theConservation of Nature and NaturalResources — now called the WorldConservation Union

IWC — International Whaling Com-mission

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negedic

jebel — an Arabic namefor a mountain or hill inan arid environment —as in Jebel Marra inSudan, Africa

jeepny — in the Philip-pines a converted and much modifiedjeep left behind by American troopsafter World War 2

jet stream — a name given to thenarrow belt of very fast winds in theupper atmosphere, between 7.5 kmand 14 km altitude moving at speedsof 45 m per second. The subtropical jet stream occurs atapproximately latitude 30° North andSouth of the equator and the subpolarjet stream between latitude 40° and60° North and South of the equator

joint — a natural fracture in a rock.Joints can occur in sandstone alongbedding planes or even in igneousrocks where cooling, during the timewhen magma solidified, led to natural‘shrinkage cracks.’ Joints are very different to faults. Withjoints there has been no movementeither side of the joint. With a fault either side slides or hasslid passed the other (see figure 6colour)

jökulhlaup — glacial meltwater re-leased as a flood when volcanic activityunder the ice heats and melts the ice –such as magma rising to the surface,heating the ground at depth andpartially melting an overlying glacier.As the pressure of the water builds upit is eventually released as a suddenflood

joule — a unit of energyjunta — a self-appointed body that has

taken over a normally elected govern-ment following a coup d’état

Jurassic — a period of geologic time,within the Mesozoic era, extendingfrom approximately 150–210 millionyears before present (see geologicaltime scale, figure 27)

just-in-time (JIT) — a system ofproduction in which all necessaryinputs of production, such as labour,raw materials and transport, aredelivered just in time to meetproduction targets and deadlines. It isespecially adopted as a managementstrategy for small production runs

juvenile water — water brought to thesurface or added to undergroundwater by rising magma

J


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K2 — the second highestmountain in the world,at 8598 m, second to MtEverest. K2 is alsoknown as Mt Goldwin-Austin and is also foundin the Himalayas

kame — a mound of roughly stratifiedsand and gravel laid down by streamsflowing from, or off, the toe of aglacier

kampong — a clustered rural settle-ment that was a village outside of thecity but has been swallowed up as thecity has grown outwards. This iscommon in Southeast Asian citiesespecially in Malaysia. They aretypically of one-storey and the tenantsof these kampongs own the land(unlike squatter settlements) withtheir own gardens, vegetables andfruit trees and fish breeding areas

kang — in China, a bed with a stovebeneath it heated by burning straw,soft coal or dry animal manure

karren — an exposed limestone surfacethat has been weathered via solutionforming grooves/furrows on the surface

karst — limestone country sometimesmarked by caves and subsurface rivers.Karst areas have formed on limestonerock that is weathered at a relativelyrapid rate by the weak acids inrainwater and surface water. The Nullabor Plain in South Australiaand Western Australia is an example ofa karst landscape where there are nosurface rivers — all are below thesurface of the land (see doline,weathering)

katabatic wind — downslope winds.Katabatic winds can be warm or cool.chinook and föhn winds are warmkatabatic winds. Cold katabatic windsare common in areas of steep slopes

where a pool of cold air accumulatesat a high altitude. This cold dense airflows downslope; for example the coldwinds flowing off the Antarctic ice capfrom the interior and the cold winds ofwinter flowing down the Hawkesburyvalley within the Sydney Basin, NSWAustralia (see anabatic wind)

Kata Tjuta — formerly known as TheOlgas (see figure 35 colour)

Kayapo indians — indigenous peoplein the Amazon rainforest, SouthAmerica

Kelvin scale — a temperature scale thatindicates 0º Kelvin as –273ºC. 0ºK isalso known as absolute zero

kettle — a depression in the landformed as a result of the melting of icebeneath the surface

key — part of a graph which explainswhat the symbols and shading used onthe graph represent

kharif — the name given to theSouthwest Monsoon (summer) inIndia and to crops grown in thisseason (see rabi)

kibbutz — a rural settlement in Israelbased on collective farming andcommunal villages. The ownership ofthe property and all profits arecommunal and the work on thesettlement is shared among theinhabitants

Koppen, Wilhelm — a climatologistwho in 1920 provided a classificationof world climates. He selected what he considered to bethe most appropriate indicators,temperature and annual precipitationvalues. This was the first attempt toincorporate both temperature andprecipitation. His classification was based on theglobal patterns of vegetation distrib-

K

ryewhy

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negedic

ution that had then been recentlypublished. His scheme includes five maindivisions:

A hot, moist climatesB dry climates C warm, moist climatesD cool, moist climates with snowy

wintersE cold climates

Kow Swamp — a famous archaeologicalsite in northern Victoria, Australia. Itwas the site of a skull that was muchlarger or robust than the Talgai skulland that of Mungo Man at LakeMungo. This suggested that there mayhave been two subspecies ofAboriginal people that enteredAustralia during the Pleistocene

kraal — a native hut village in southernor central Africa; also an enclosure forlivestock in southern or central Africa

Krakatoa — a small volcanic islandbetween Sumatra and Java inIndonesia. Krakatoa began to erupt 20 May 1883 with major explosions 26 and 27 August 1883. One explosionwas the loudest noise on Earth, andcould be heard in Australia 4800kilometres away. Although the northern face of thevolcano (600 m altitude) was blownoff there were no immediatecasualties. However 36,000 people

died on the islands of Java andSumatra as a result of the tsunami thatwas produced

kraznozem — a deep (more than onemetre), red-brown soil typicallydeveloped on volcanic rock such asbasalt. The texture of these soils tendsto show a gradual change through thesoil profile, such as from upper clayloams to deeper light clays, with nodistinctive boundaries or horizons.The red colour is derived from theabundant iron oxide. These soils arevery fertile as are most volcanic soilsand are common on the south coast ofNew South Wales. Here rich pasturesupports a dairy industry – (see resid-ual sites)

krill — a small crustacean found in thewaters surrounding Antarctica — alsoknown as Antarctic Shrimp

Kung-she — a collective farm in thePeople’s Republic of China (seecollective farming, commune)

Kutikina Cave — located in Tasmaniathis is thought to be the southernmostoccupied site in the world during thelast glacial period 20,000–15,000years ago

Kyoto Convention — an internationalconvention held in Kyoto, Japan,December 1997 with the aim of settingglobal and national targets forgreenhouse gas emissions

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labour intensive —refers to productionwhere a large workforce is used rather thanmachinery. Many peopleare used in traditional

rice padi in Southeast Asia. This is an example of labour intensiveagriculture (see capital intensive,intensive farming/agricultural/landuse)

lacustrine — related to lakeslag industries — those industries that

do not undergo growth due to self-initiative or internal forces (such asimplementing new technologies) butrather rely on the expansionelsewhere in the economy

lagoon — a body of water between theland and the sea separated by landformed from the deposition ofsediment such as sand by the action ofwaves. Bays are often cut off from thesea when a sand spit develops acrossthe bay. The bay then becomes a quietlagoon

lahar — volcanic mudflowlaissez faire — a theoretical economic

system in which there is completefreedom in the flow of goods andservices with prices determined bysupply and demand

Lake Baikal — located in far easternRussia Lake Baikal is the world’sdeepest lake at over 1.6km deep andcontaining approximately 18% of theworld’s fresh water

Lake Mungo — a dry lake insouthwestern New South Wales. LakeMungo is a significant archaeologicalsite (figure 36). It was once part of theWillandra Lakes system when lakelevels were full approximately 30,000years ago. The area was much wetter

than it is now with 20 metre deeplakes abundant with native fish. LakeMungo provides evidence of earlyAboriginal occupation in southeasternAustralia. A full skeleton dated atapproximately 26,000 years oldprovides the oldest evidence of ritualcremation in the world with the bodyof Mungo Man carefully arranged in agrave and adorned with red ochre.Lake Mungo is now part of theWillandra Lakes World Heritage Site(see Kow Swamp, figure 39)

Lake Titicaca — located in Peru andBolivia (South America) Lake Titicacais the highest lake in the world at 3810 metres above sea level

land breeze — a local breeze blowingfrom the land to the sea, especially atnight, as a result of differences in airpressure. During the night andespecially in the early morning theland cools down appreciably, therebycausing air above it to have a relativelyhigh pressure. However the searemains relatively warm as it can retainits heat that it collected during theprevious day. The air over the seatherefore has relatively low pressure.Since air moves from areas of highpressure to areas of low pressure, awind blows from the land to the sea(see air pressure, sea breeze)

landcare — as a result of deterioratingenvironmental quality, such as soilerosion, salinity habitat loss, theAustralian Government establishedLandcare Australia in 1989. It attempted to draw attention to theplight of the natural environment,promote ecologically sustainable prac-tices and to encourage communitygroups and others to become activeparticipants in ecologically soundpractices.

L

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The 1990s was declared Decade ofLandcare and many groups haveemerged supporting a Landcare ethic.Urban Landcare groups engage inweed control, water qualitymonitoring and bush regeneration(see ecological sustainability)

land consolidation — a type of landreform where small parcels of land arecombined or amalgamated into largerparcels

land degradation — the reduction ordeterioration in the quality of land.

Soil erosion, soil salinity anddeforestation are examples ofprocesses that contribute to landdegradation (see quoquake)

landform — any natural feature of theEarth’s surface having a distinctiveshape such as a plateau, slope, valleyor mountain range

land invasion — an urban invasion,common in Latin America, wherebyprospective squatters occupy a pieceof land in order to erect shelters

landlocked — a state, country or

Figure 36 � Climate and lake levels at Willandra Lakes, NSW

Source: J. Flood, Archaeology of the Dreamtime, Collins1983, page 43

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catchment area that has no directaccess to the sea. Landlockedcountries include Rwanda, Zimbabweand Chad in Africa, and Austria,Switzerland and Slovakia in Europe.The Aral Basin is a landlockedcatchment area (see internal drainage)

land reclamation — the treatment of anarea to increase the area of productiveland. Land is reclaimed, for example,by filling in land with various types ofwastes (this is sometimes calledlandfill)

land reform — changing the characterof land ownership such as amalgam-ating small land holdings into largerunits or breaking up large land-holdings into smaller units. Landreform may also lead to a change inthe system of land tenure (see landconsolidation)

LANDSAT image — an image takenfrom a satellite called LANDSAT whichwas launched in 1975. LANDSATprovides images of the Earth’s surfacewith a resolution of 30 metres (seeSPOT, remote sensing)

land system diagram — a diagramdrawn to summarise landformpatterns in an area. For example, anarea may show a series of arid plateauareas all with steep escarpmentscovered with low forest and widelowland plains with dried up saltlakes. Instead of drawing all of these, aland system diagram simply showsthese three related landform types andassociated biophysical character togive an impression of the recurringpatterns that can seen in thatenvironment

land tenure — land ownership, such asfreehold tenure, where a person orfamily owns the land or leaseholdwhere a person rents (or leases) theland from a landowner

land use — the way the land is used egagricultural land use where land isused for various types of farming suchas dairy cattle, wheat or sheep

La Niña — an event that occurs due tothe upwelling of abnormally coldwater in the central and eastern Pacific

Ocean while sea surface temperaturesbecome warmer in the western Pacific.As a result of the warmer conditions inthe western Pacific more intense lowpressure areas form over Indonesiaand northern Australia and wide-spread flooding occurs in easternAustralia (see El Niño)

Lapp — common name for theindigenous people of Scandinavia (seeSaami)

lapse rate — see environmental lapserate

latent heat — heat stored in watermolecules (often called hidden heat).As solar radiation is absorbed by watermolecules this energy is used in theprocess of evaporation. Upon coolingthis energy is released whencondensation occurs. When air rises itcools at the (dry) adiabatic lapse rate(about 6.5°C per kilometre) thetemperature of the parcel of air fallsand condensation occurs; latent heatis then released into the atmospheremaking the air warmer and so morebuoyant. The air rises still further ascan be seen in thunderstorms

lateral erosion — erosion on the banksor sides of features such as rivers. Theenergy of a stream wears away andtransports material downstream. Lateral erosion of a stream has theeffect of widening the stream as well asleading to the stream migrating acrossits floodplain in the case of manymeandering streams (see meander)

lateral moraine — sediment that hasbeen transported by a glacier andaccumulated along the sides of theglacier (see medial moraine)

laterite — a deep, red soil rich in ironand aluminium oxides but poor insilica. Such soils are commonly, butnot only, found in tropical andsubtropical areas where high rainfallleads to the leaching out of manyminerals such as quartz (silica). Only the fine infertile iron-rich clayremains behind. The high temperatures and rainfallensure that weathering of parent

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material (bedrock) occurs deepbelow the surface leading to many ofthese soils being more than 10 metresdeep.In more temperate latitudes such aseastern Australia laterites are commonwhere parent material is rich in ironminerals and the topographyproviding a warm moist (sheltered)microclimate.In other circumstances red, iron-richsoils have been described as ‘lateritic’such as over sandstone bedrock. A climatic reason for the occurrence oflaterite in this case does not have to beinvoked. The influence of geology canbe equally important where iron-richbedrock can lead to these soils (seeduricrust)

latitude — the number of degrees aplace is north or south of the equatoreg, 20°S (see figure 37)

Laurasia — the landmass that broke offfrom the northern part of thesupercontinent of Pangaea, approx-imately 300 million years ago (seecontinental drift, Gondwanaland)

lava — molten material that is extrudedfrom a volcano or fissure within theEarth’s crust. Because of its differentcomposition of gases molten materialbeneath the Earth’s surface is calledmagma (see aa, extrusion, pahoehoe,volcano)

leachate — a term to describe theaccumulated material that is the resultof leaching of minerals through thesoil. Another kind of leachate is thatwhich results from the accumulationof liquids such as oils, paint and paintthinners and organic decompositionin waste disposal sites. This type ofleachate is very damaging if it finds itsway to waterways because an enorm-ous amount of dissolved oxygen isused up from the water to break downthe leachate. So much dissolvedoxygen can be used up that thestream, for example, can become anaquatic desert as aquatic life diesthrough lack of oxygen

leaching — the downwards movementof material in solution through a soilprofile. This is very different toeluviation (see figure 53)

leasehold land — land that is owned bygroups such as governments,commercial organisations and individ-uals but is leased (rented) back topeople or organisations. People ororganisations leasing this land do notown the land; they are said to haveleasehold tenure (see freehold tenure,land tenure)

lee or leeward slope — the shelteredside of a hill or mountain. A slope thatreceives most rainfall or the greatestpercentage of wind is called thewindward slope. With winds app-

Figure 37 � Latitude and Longitude

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roaching the eastern side of theEastern Highlands, Australia, thewestern slopes are described asleeward slopes because they areprotected from the easterly winds (seerainshadow)

legend — part of a map that explainswhat the various symbols used on themap represent

Leptospermum — a shrub or small treecommonly referred to as a tea-tree

levee bank — a sand deposit along thebank of stream resulting from thedeposition of sediment duringoverbank flow or flooding

liana — a long, thick vine, especially inrainforests, that winds around thecanopy and can hang down towardsthe ground (Figure 38 colour)

life expectancy — the number of yearsthat a person can expect to live. Accessto health services and better nutritioncontribute to a greater life expectancyin many developed countries than inmany developing countries. For example life expectancy inAustralia is approximately 78 years formales and 84 years for femalescompared to 39 years for males and 42years for females in Ethiopia (Africa)

Some Examples of Life Expectancy Worldwide

light industry — manufacturingconcerned with the light weight/volume raw materials and the outputor production of a light weight/volumeproduct. Examples include furnituremanufacturing, textiles and computerproduction (see heavy industry)

lignite — commonly known as browncoal (see bituminous coal)

lignotuber — a woody structure,consisting of buds that sprout fromthe base of a tree when the upper partof the tree has been damaged ordestroyed by fire

limestone — a sedimentary rockcomposed largely of calcium carbon-ate. An example of limestone is rockproduced from accumulated coral.Limestone landscapes include thosedominated by caves as slightly acidwater dissolves and then removes thecalcium carbonate of these rocks.Jenolan Caves, NSW and The NullaborPlain, Western Australia and SouthAustralia are Australian examples oflimestone areas (see dolomite , karst)

limnetic vegetation — referring tofreshwater lakes and ponds

linear — relating to a line such as alinear scale or linear settlementpattern (see ribbon development)

linear sprawl — development thatoccurs along important transport linessuch as highways leading away fromthe centre of an urban area (alsoribbon development)

line of best fit — a type of trend line.This is a straight line and when it isdrawn the sum of the spacing betweenthe dots plotted on one side of the lineshould be the same as the sum of thespacing on the other side of the line.In many instances this can be donevisually by estimating the trend shownby the plotted data

lithify — turn to stonelithology — relating to the large-scale

characteristics of rockslithosphere — the Earth’s crust and

upper mantle that includes soils,landforms and bedrock. The thickness of the lithosphere variesgreatly. The oceanic lithosphere isrelatively thin and extends forapproximately 6–10 kilometres. Thecontinental lithosphere is muchthicker extending over 20 kilometresbeneath the continents (see sial, sima)

lithosere — plant succession that hasdeveloped from a rocky surface

Region Years Example from region

World 65Africa 53 Sierra Leone 39.0Europe 73 Hungary 69North America 75 Honduras 56South America 69 Bolivia 59.5Asia 65 Afghanistan 43.5Australia 80

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Little Ice Age — a change in climatebetween 1590 and 1850 that saw acooling of 1ºC over much of WesternEurope. During this period glaciersadvanced by up to one metre per year

littoral zone — the near shore zone; theseafloor area lying between the highand low tide marks (see sublittoralzone, supralittoral zone)

loam — a relatively rich, friable soilcontaining a relatively equal mix ofsand and silt and a smaller proportionof clay — hence the expressions loamysoil and loamy texture (see soiltexture)

local relief — the difference betweenthe highest point and lowest point inan area or along a transect (see relief)

loess — a soil that has formed from thedeposition of wind-blown dust. The two common sources of this dustare i) from desert areas where dust isblown from the unconsolidated sands;and ii) in areas where winds tend to be

strong in the outer areas of glaciallandscapes and even periglacial areas.Wind has blown the fine sediment thatwas deposited by glacial meltwaterforming thick layers of loess in areassuch as western China

longitude — the number of degrees aplace on the Earth is east or west ofthe prime meridian (0°) (see figure37)

long profile — the path taken by astream bed along its course from itsheadwaters to its mouth (see gradedprofile and thalweg)

longshore drift — the movement ofsediment, such as sand, along thecoast. When waves approach thebeach the swash moves up the beachat an oblique angle; the return flow ofwater is at right angles to the beach. In this way sand is able to move alongthe beach in a zigzag movement.Longshore drift can lead to the loss of

Figure 39 � Cross section (A) and a plan view (B) of the Lake Mungo lunette, Willandra Lakes, NSW

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sand from one area of the beach andthe accumulation of sediment atanother such as to clog the mouth ofany stream entering the sea. As a result of this wave movement, alongshore current is set up along thecoast. This longshore current can leadto depositional landforms such assand spits (see backwash)

Lösch, A — a German economic geog-rapher (1906–1945) who furtherdeveloped W. Christaller’s central placetheory. Rather than central places beinggrouped on the basis of population sizeand function as proposed butChristaller, Lösch suggested that themost efficient settlement pattern wasthat showing the continuous prog-ression in population size and numberof functions (see Christaller, W)

low income economy — thosecountries with a GDP per capita lessthan $750 eg India, Ethiopia andVietnam (see high income economy,middle income economy)

low order goods — in the study ofpopulation, settlement and economicgeography, low order goods are thosethat are relatively cheap and those thatpeople are not willing to travel longdistances to buy. For example people will travel onlyshort distances to buy a newspaper ora loaf of bread — these are low ordergoods (see high order goods)

lower catchment — the area of the rivercatchment close to its outlet to the seaor lake

low pressure cell — an area of lowpressure consisting of closed isobars.In a low pressure cell the value of theisobars decreases towards the centre(ie the pressure decreases). In theSouthern Hemisphere winds blow in aclockwise direction around a lowpressure cell (see coriolis force, figure26, high pressure cell, figure 55)

lunar eclipse — this occurs when theEarth casts a shadow on the Moon asthe Earth passes between the Sun andthe Moon. Where the Moon iscompletely obscured this is called atotal eclipse; when partially obscuredit is called a partial eclipse. A lunareclipse occurs only on a full Moon butnot all full Moons (see solar eclipse)

lunette — a crescent-shaped sand duneon the leeward side of a now dry lake(figure 39). Lunettes are composed ofa mixture of quartz sand as well as clay.This sediment has typically accum-ulated on the downwind side of thelake. Lunettes are common in presentday semi-arid areas such as insouthwestern NSW, in the WillandraLakes region, Australia. Lunettesformed as a result of fluctuating lakelevels and eventual drying over aperiod lasting the past 50,000 years.One of these lakes, called Lake Mungo,records evidence in its lunette of earlyAboriginal occupation as well asclimates during the past 50,000 years(see figure 36)

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maar — a landformcaused by a volcanicexplosion and consist-ing of a crater which isgenerally at groundlevel and is considerablywider than deep.

Typically a lake or pond forms in thisdepression (see volcano)

maar lake — a lake in a volcanic craterMachu Picchu — these stone ruins of a

15th century Inca city are located at3500 metres above sea level in thePeruvian Andes Mountains. Thecharacteristic terraces show clearly thetremendous engineering skills at thetime

magma — molten rock beneath theEarth’s crust. When magma solidifiesbelow the surface it forms igneousrock such as granite; when it solidifiesabove the surface it forms igneousrock such as basalt

magnitude — a measure of anearthquake’s intensity. On the Richterscale, with magnitudes ranging fromzero to ten, each increase in mag-nitude is ten times the intensity of theprevious magnitude. Instruments can normally only detecta magnitude of 2 on the Richter scale;a magnitude of 5 leads to structuraldamage of buildings and a magnitudeof 8 sees large buildings destroyed. However, the impact of a 2, 5 or 6magnitude earthquake will be verydifferent between areas depending onsuch features as underlying geology,soil type, slope, as well as the densityand type of settlement structures. The Richter scale measures theamount of energy released by eachshockwave produced by the earth-quake. The Richter scale is alogarithmic scale. Each unit increases

by 2.4 orders of magnitude (or a 240-fold increase in energy). Very few earthquakes have exceeded8.9 on the Richter scale

majority world — also known as thedeveloping world which comprises thegreat bulk of the world’s population(see developing country and minorityworld)

mallee — scrub vegetation dominatedby Eucalyptus species. The mainvegetation community is that of denselow bushes (1–2 metres high) oftenwith a sparse distribution of smalltrees (5–10 metres tall) — hence theterm mallee scrub and malleeeucalypts. Mallee is typically found inthe drier areas of southeast andsouthwest Australia

maloca — a communal dwelling forfamilies of the Yanomami people inBrazil; sometimes called a ‘long-house.’ It is also used as a place forrituals and dancing. These malocascan be up to 50 metres in diameterand up to 20 metres high

Malthus, Thomas — an Englisheconomist who, in 1798, argued thatpopulation growth cannot besustained because of its rate of growth.He argued that because populationgrowth increases exponentially andfood supplies increase only at a linearrate population will be limited by thefood supply available to it. Populationnumbers will be modified largely byforces such as disease and war. Histhesis has been found to be false asmodern technology such as geneticengineering is providing HYVs

mammal — a vertebrate animal thatfeeds it young with milk created frommammae (nipples). With theexception of monotremes mammalssuch as kangaroos and koalas do not

M


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lay eggs but rather give birth to liveyoung

Man and the Biosphere Program — aninternational program coordinated byUNESCO to develop a worldwidenetwork of key biophysical regionsand to identify their biophysicalcharacter. In this way the interactions betweenpeople and the biosphere can beidentified and the need formanagement programs such as landrestoration and wildlife conservationcan be addressed (see biophysicalenvironment)

mangrove — any tree or shrub com-munity where low trees are growingmostly in marshes or tidal areas. Beingof the genus Rhizophora of theRhizophoraceae they are characterisedby many interlacing above-ground roots

mantle — a zone within the Earthextending from between 20–70 kmbelow the surface to a depth of nearly3000 km. The mantle lies between the Earth’ssolid crust and the Earth’s core.

The mantle includes massiveconvection cells with heat generatedby radioactive decay of minerals.These cells redistribute and drive themove of the crustal plates andassociated continental drift (see platetectonics)

manufacturing — the making of goods.There are two types of manufacturing:

� Processing — the changing of araw material such as iron ore intosteel, or bauxite into aluminium

� Fabricating — the assembly ofalready processed materials into afinished product such as carassembly, furniture assembly

map — a diagram using a variety ofsymbols representing part of theEarth’s surface usually drawn at adifferent scale

map reference — (Figure 40) see gridreference and area reference

map scale — see scalemarble — metamorphosed limestone or

dolomite (see metamorphism)marginal land — land that only just

supports present land use or may only

Figure 40 � Map References

aryewhy

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just support a proposed land use. Any adverse effect on the land, such asdrought or the increasing intensity ofuse, will lead to a response by thatland in the form of land degradationmaking the use of that landuneconomic

mariculture — the commercial growingof marine animals and plants (eg fish)

maritime climate — the term used todescribe conditions close to coastalareas. A maritime climate has anumber of characteristics:

� high total annual rainfall� small annual temperature ranges� small diurnal temperature ranges

maritime zone — the area of the sea orocean surrounding land subject tonational or international law. Somestates claim exclusive access tosurrounding waters for use of seabedresources. Beyond these maritimezones are the high seas

market area — the size of and the areaserved by local markets

market town — centres of exchange;these are typically collection anddistribution centres for local products

marram grass — a type of grass(Ammophila arenaria) commonlyfound on coastal sand dunes. Its rhizomes and roots extend formany metres. As a result marramgrass is used extensively for dunestabilisation to minimise erosion

marsupial — mammals having noplacenta and supporting their youngin a pouch eg a kangaroo, koala andwombat. Most of the world’smarsupials are found in Australia.However most of Australia’s fauna areplacentals

Marxism — a system of thoughtdeveloped by Karl Marx: i) used inurban geography to explain that theurban geography of capitalism is theoutcome of the relationship betweenpolitical and economic forces withinsociety; and ii) used in developmentgeography to explain that classstruggle is the main agency ofhistorical change

mass movement — the downslopemovement of earth materials such assoil under the influence of gravity andtypically lubricated by water. Examplesof mass movement include soil creepand landslides

Maunder Minimum — a period in Earthhistory between 1650–1700 whenthere was virtually no sunspot activity.This period coincided with what asbeen called the Little Ice Age in Europe(see sunspots, ice age)

MDB — see Murray Darling Basinmean — see arithmetic meanmean deviation — a measure of the

dispersion in a set of statistical dataindicating the extent to whichindividual scores deviate from thearithmetic mean. It is calculated bysumming the absolute deviation of allscores from the arithmetic mean thendividing by the number of scores mean deviation = Σ| x-x |

nwhere | x-x | = the absolute differencebetween each value (x) and the mean(x)Σ = the sum of all of these valuesn = the number of scores

meander — a natural bend in a river.Meanders are more common down-stream and are the result of theprocesses of erosion and depositionalong its course (add incisedmeander)

meander scroll — a depositionallandform, typically within a river’smeander belt that reflects the previousposition of the meandering channel.As a river migrates across itsfloodplain its abandons its previouslevee deposits normally parallel to themain channel. These meander scrollscan be seen as sandy ridges on thefloodplain (see figure 25, levee bank)

medial moraine — sediment that hasaccumulated in a line at the centre of aglacier as a result of the joining of thelateral moraines of one side of twoglaciers (see moraine)

median — in an array of statistical data,arranged from the lowest to highest

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score, the median is known as the‘middle score’

mediterranean climate — a climatethat has wet winters and dry summers.Countries that have a Mediterraneanclimate include those of southernEurope (eg Italy and Greece).Mediterranean climates are also foundin southern Australia such as theBarossa Valley in South Australia

megacity — a very large city typicallywith a population exceeding 10million people (eg Mexico City,London and Sao Paulo)

megafauna — more than 15,000 yearsago giant marsupials roamed easternAustralia. From about 80,000 years agothese giant marsupials were part of theAustralian environment. For example there were theDiprotodons – wombat-like but thesize of a rhinoceros; the Procoptodon– a three metre tall kangaroo; and thecarnivorous Thylacoleo – known asthe marsupial ‘lion’ (the size of aleopard). The period 25,000 to 15,000years ago was a time of environmentalupheaval in eastern Australia assoc-iated with continental drying,declining water supplies, andvegetation changes. At the same timeanother change occurred; theincreased use of specialised weaponsand of fire employed by Aboriginalhunters. These all threatened Australia’smegafauna. It is much debated as tothe cause of the megafauna’sextinction. Three possible causessingly or in combination wereresponsible

� climate change associated with thedrying of the Pleistocene ice age

� overkill by hunters as a source offood in an expanding population

� habitat loss via firing by Aboriginalpeople (see carnivore)

megalitre — one million litres, or 1000cubic metres (also written as ML)

megalopolis — a very large continuousbuilt-up urban area usually over about15 million people. Examples include

Tokyo, New York and Mexico City. Theterm was first applied to the BosWashregion in the USA taking in Boston,New York and Washington

Melanesia — that area of islands to theimmediate northeast of Australia suchas Papua New Guinea and theSolomon Islands

Melanesian — short, dark-skinnedpeople with frizzy hair who occupy theislands to the northeast of Australia(see Melanesia)

meltwater — water that flows as a resultof the melting of glaciers or snowfields

mental map — a map of theenvironment that a person has in hisor her mind. The representation of theenvironment will be very different tomore formal maps such astopographic maps. The image that aperson has of an area will beinfluenced by the person’s exper-iences of, and attitudes to, that area

Mercalli scale — a scale between 1 and12 used to indicate the strength of anearthquake based on the amount ofdamage the earthquake does (seeRichter scale)

Mercator projection — a map projec-tion of the Earth which representslandmasses in their correct shapes butdistorts their areas. For example,Australia and Greenland appearsimilar in size where in fact Australia ismore than three times the size ofGreenland – 7.6 million km2 comparedto only 2.1 million km2)

meridian — a line of longitude; eg theprime meridian; the 20°E meridian oflongitude

metabolic heat — heat generated fromwithin the body

metamorphism — in geology, a processwhere a rock or mineral changes suchcharacteristics as its composition,structure and texture, as a result of theapplication of heat and pressure. As a result of overlying pressurebeyond normal burial and often overone kilometre, rocks can change theircharacter — for example limestone

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can change to marble. An igneousintrusion may rise through the crustand heat the surrounding rock. Theminerals in these rocks can bechanged – for example mudstone intoslate (see igneous rock)

mesa — a flat-topped hill. Mesasindicate that erosion has beenrelatively rapid horizontally (becauseit is narrower than a plateau). The surface of a mesa often has a moreerosion-resistant duricrust. A mesatends to be wider than a butte (seefigure 20)

mesosphere — an area of the Earth’satmosphere extending betweenapproximately 50 km and 80 kmaltitude. The temperature within themesosphere increases with height (seefigure 2)

mesophyte — a plant that grows inconditions that are neither very wetnor very dry (see Hydrophyte andXerophyte)

methane — a gas that occurs in theatmosphere (CH4). Methane is pro-duced from a number of sources suchas agriculture (rice padi and ruminantanimals such as cows); the Arctictundra as permafrost melts due toglobal warming; gases released fromdecomposing material from municipaltips. Methane has been increasingrapidly (just like carbon dioxide)reflecting the growth in populationnumbers. Methane is a majorgreenhouse gas

metropolitan area — the suburbanarea surrounding the commercial coreof a city — made up mostly of theresidential area of the city

Mezzogiorno — the poorer agriculturalsouth in Italy

M.I.A — Murrumbidgee Irrigation Area(NSW, Australia)

microclimate — the climate of a smallarea. The climate of the large areaaround us might be described as arid.However there may be a shelteredvalley where the slopes provide shadeand therefore cooler temperaturesand there may be a permanent stream

at the bottom of the valley. The valleyis said to have a microclimate that isvery different from the environmentaround it

micron — one thousandth of amillimetre (or a millionth of a metre)

Micronesia — the very small islands inthe western Pacific north of Melanesia.These islands include Guam, Truk andPalau

Mid-Atlantic Ridge — a long linearridge (or mountain chain) under theAtlantic Ocean with North Americaand South America to the west andAfrica and Europe to the east. One ofmany ocean ridges, this ridge formsthe constructive boundary of oceanplates either side of it. Along the ridgemagma rises to the surface, spreadingand creating new ocean floor. Theisland of Iceland is being split apart asthe ridge passes through it. Evidenceof this includes much volcanic andearthquake activity on the island (seefigure 17, mid-ocean ridge, platetectonics)

midden — a garbage or refuse heap. Inareas of coastal Australia earlyAboriginal communities disposed ofshellfish and the skeletons of fish inmiddens especially at the entrance ofsome caves such as in Royal NationalPark and Botany Bay National Park,NSW, Australia

middle income economy — countrieswith a GDP per capita greater than$750 but less than $9500 eg Russia,Brazil and Indonesia (see high incomeeconomies, low income economies)

mid-latitudes — those areas betweenapproximately latitude 20°–40° northand south of the equator (see latitude)

Mid-ocean Ridge — a line of connectedvolcanoes – fissures forming amountain chain under the sea, theresult of the separation of plates andthe upwelling of magma. The mid-ocean ridges are said to beconstructive plate boundaries, theplates spreading sideways andultimately ‘consumed’ at subductionzones (destructive boundaries) (see

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figure 17, continental drift, East PacificRise, Mid-Atlantic Ridge, plate tecton-ics, volcano)

Milankovitch, M — in 1920 MilutinMilankovitch performed a range ofcalculations which showed that theEarth’s position in space, its tilt andorbit around the Sun, all change in aregular manner. He claimed thesechanges affected incoming solarradiation and produced three cycles of96,000, 42,000 and 21,000 years (seeMilankovitch cycles)

Milankovitch cycles — these are cyclesshowing variations in the Earth’s orbitaround the Sun and rotation on itsaxis. These are used to explain thecause of glacial periods in thePleistocene. The position of the Earthrelative to the Sun changes over timethereby affecting the receipt ofinsolation. There are three cycles:

• changes in the eccentricity of theEarth’s orbit (every 96,000 years) –the Earth has an elliptical orbitaround the Sun (rather thancircular) so the length of seasons

varies over the years. As a resultinsolation increases or decreases

• changes in the precession of theequinoxes (every 21,000 years) –this means that the time of yearthat the Earth is closest to the Sun(perihelion) varies

• changes in the obliquity of theecliptic — there is a variability inthe tilt of the Earth’s axis from21°39' to 24°36'; the greater the tiltthe greater the difference betweensummer and winter

These cycles are synchronous with theadvance and retreat of ice during thePleistocene

milieu — the atmosphere created by thetotal surroundings and felt orexperienced by those people within it.The milieu created by a rainforestenvironment is very different from thatcreated by an alpine environment; justas the milieu characterised by acommunity of a particular ethnicorigin is very different from that ofanother origin

Underfit Stream of the Osage Type Manifestly Underfit Stream

meandering stream

meandering stream

valley walls

valleywalls

Figure 41 � Misfit Streams

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millionaire city — a city with more thanone million people

minority world — also known as thedeveloped world which compromisesonly about 35% of the world’spopulation (see majority world)

misfit stream — a stream whosechannel is smaller than the valley inwhich it flows (Figure 41). The stream channel may follow thesame pattern as the valley withinwhich it flows; this is called anunderfit stream of the Osage type.Where there are meanders within avalley meander, this is called amanifestly underfit stream (seeunderfit stream)

mode — in a set of statistical data themode is the most common or mostfrequently recorded score

mode of production — the organis-ation of social relationships under-pinning economic activity, theproduction of surpluses, and thereproduction of social life.

Capitalism and feudalism areexamples of modes of production

Moho — (also called the MohorovicicDiscontinuity) the boundary betweenthe Earth’s crust and the underlyingmantle. Because of the different depths of thecontinents and the oceans, the Mohois approximately 40 kilometres belowthe continents and 10 kilometresbeneath the oceans

monoculture — the growing of a singlecrop. A farm may be concerned withjust wheat, maize or cotton. A typical example of monoculture is aplantation where a single crop isdeveloped such as rubber, or tea (seecommercial farming)

monopoly — (i) a market where there isonly one producer eg one producer ofa type of shoe; (ii) the situation wherea person or organisation has solecontrol of a feature eg an organisationhas a monopoly on the sale of a type ofbattery

Figure 42 � Monsoons

SCALE: 1 CM = 900 KM

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monotreme — any egg laying mammalcomprising of the Duckbilled Platypusand the Echidna (of which there aretwo species)

monsoon — a condition of theatmosphere whereby air pressuresystems and wind patterns arereversed between summer and winter(Figure 42); the monsoon can bedescribed as a seasonal reversal ofwinds. For example a low pressure systemforms in summer over northernAustralia and a high pressure systemforms over Asia (their winter). Winds blow from the north over Asia,picking up moisture over the waters ofSoutheast Asia, making northernAustralia very wet. In winter over central and northernAustralia an area of high pressureforms whereas in Asia (their summer)an area of low pressure forms. Winds then blow from the arid areas ofthe central Australia making northernAustralia dry. The result is a seasonalclimate characterised by wet summersand dry winters (see generalcirculation)

monsoon climate — characterised bywet summers and dry winters

montane — referring to a mountainenvironment; relating to, growing inor inhabiting mountain areas

Montreal Protocol — in agreement,initially signed by 27 countries inCanada in 1987, to limit theproduction of Ozone depleting CFCs

moraine — sediment that has beeneroded, transported and often depos-ited by a glacier (see deposition,erosion, glacier, lateral moraine,medial moraine)

morbidity — a value which expressesthe frequency of disease or illness in apopulation

moratorium — to temporarily stop acourse of action

morphology — in urban geography thecharacter or physical form of an urbancentre. The morphology of an urbancentre may describe the different landuse types, transport facilities and

architectural style within that centre. The morphology of an urban centrecan change over time as seen witheffects of urban consolidation as wellas urban decay and urban renewal

mortality — an expression that gives anindication of the frequency of deathwithin a population

mountain — a major landform on theEarth’s surface that extends over 600metres above sea level. Mountains aretypically of high altitude with steepslopes showing a distinctive altitudinalzoning of climates and vegetation

Mt. Pinatubo — a volcano in thePhilippines that erupted in June 1991killing more than 300 people. The2km-wide crater produced ash thatcovered an area of nearly 1000 km2

with ash circling the globe in thestratosphere for three years

mulga — the name given to a type ofscrub vegetation in the drier interiorof Australia dominated by acacia(wattle) species

multilateral agreement — an agree-ment between a number of nations(see bilateral agreement)

multilateral aid — see foreign aidmultiple land use — a system of land

use and resource management thatprovides for different land use types inthe one area (eg mining and grazing)

multiple nuclei model — a model ofthe internal structure of cities (Figure58). Developed by the geographers E.L. Ullman and C.D. Harris the modelis based on the premise that urbangrowth occurs around separate nodesor nuclei. A particular area may attractfinancial and commercial functionstypical of a CBD and through theprocess of agglomeration. Other functions such as industrial andresidential activity are attracted to sitesaround these nuclei. As a result theland use pattern can be seen ascomprising one or more discrete areasof a land use type around these nuclei(see concentric zone model, metro-politan area, sector model)

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negedi

multiplier effect — any economicactivity generated indirectly fromservices and industry dependent upona major development

Murray Darling Basin — the basin orcatchment area made up of two majorrivers – the Murray River and theDarling River and their manytributaries covering an area ofapproximately 1.02 million squarekilometres or 1/7 of the Australiancontinent. The northern extent of the

basin lies in southern Queensland andreaches the sea at Lake Alexandrina inSouth Australia. The rivers drain animportant resource of Australia. Theland supports a wide range ofagricultural land use such as sheepgrazing, beef cattle and dairy cattlegrazing and crops such as a wheat,corn, and maize

mutualism — where two species livetogether and both derive benefit

M.Y. — million years

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nadir — the point inspace directly oppositethe zenith (ie at 180°).The point directly abovean observer at 90°N iscalled the zenith; the

point at 90°S is called the nadirnation — a group of people with a

shared culture and experience withina particular area — in many caseswithin country borders but often thisis not the case. For example, there areover 500 nations in the Americas

National Conservation Strategy — anAustralian Government response, in1983, to the World ConservationStrategy. The NCS has threeobjectives: i) to maintain and improvethe quality of ecological systems; ii) tomaintain genetic diversity on theplanet; and iii) to ensure sustainableuse of ecosystems as well as flora andfauna. Landcare is part of the NationalConservation Strategy

national estate — those places andfeatures of the natural and culturalenvironment that have special valuesuch as aesthetic, historic, social or

scientific significance to the presentcommunity and future generations.

nation state — the political unit ofpeople living in a defined territory,with government authority in theireconomy, political organisation andexternal affairs (NSW Board ofStudies)

NATO — North Atlantic TreatyOrganisation

natural disaster — any natural event,such as an earthquake, tropicalcyclone or bushfire, where there is asignificant loss of life or property

natural hazard — any natural eventsuch as an earthquake, tropicalcyclone or bushfire where people seea perceived risk in terms of life orproperty (see natural disaster)

natural increase — (of population) theincrease in population by subtractingthe number of deaths from thenumber of births

natural resource — an element, orfeature, of the biophysical environ-ment that has actual or perceivedvalue to people. Examples of natural

N

Death Tolls from Natural Disasters 1960 to 1987Hazard DeathToll Largest Event and Date Death Toll

Tropical Cyclones 622,360 East Pakistan 500,000(Bangladesh) 1976

Earthquakes 497,600 Tangshan, China 1976 250,000

Floods 36,300 Vietnam, 1964 8000

Avalanches and Mudslides 3002 Peru, 1987 25,000

Volcanic Eruptions 27,459 Columbia, 1985 23,000

Tornadoes 4500 East Pakistan 540(Bangladesh) 1969

Snow, Hail and Windstorms 3078 Bangladesh, 1986 300

Heatwaves 1000 Greece, 1987 400

Source: E Bryant, 1991, Natural Hazards, Cambridge University Press 1991, page 126


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resources include water, forests,minerals, soil and wilderness (seerenewable natural resource; non-renewable natural resource)

nautical mile — 1.852 kilometresneap tide — the rising tide (see tides)neighbourhood — an urban district

occupied and dominated by anidentifiable subculture to which mostpeople conform

neocolonialism — a term describingthe tendency of a powerful developednation gaining economic and/orpolitical influence (control) over anindependent developing country. For example the influence of dev-eloped countries in the newlyemerging nations of the SouthwestPacific and east and west Africa

neotectonics — the study of landformsaffected by recent earth movementsalso called morphotectonics (see platetectonics)

net migration — The differencebetween immigration andemigration. This may be positive ornegative indicating population growthor population decline

network — a general term, whichdescribes the multiple number ofpathways, joined together eg transportnetwork, food web

New International Economic Order —the mid-late twentieth century sawincreasing economic and socialdisparities between so-called dev-eloped and developing countries. A group of developing countries dem-anded a new international economicorder be set out formerly by a UnitedNations declaration in 1974. It ‘calledfor the replacement of the existinginternational economic order, whichwas characterised by inequality,domination, dependence, narrow self-interest and segmentation, by a neworder based on equity, sovereignty,equality, interdependence, commoninterest and cooperation among Statesirrespective of their economic or socialsystem’

(the) new urbanism — a sentimentalvision of the past relying on history to

provide a method of ensuringcommunity identity in the present.The concept is a reaction to globalis-ation. At its roots it is a reflectivemoment based on nostalgia –attempting to escape from theisolation of modern urban life and thecomplexity and pace associated withglobalisation

newly industrialised country (NIC) —a county that has recently experiencedrapid industrialisation since the1960s and 1970s after previouslybeing considered an economically lessdeveloped country. Examples of NICsinclude those of Southeast Asia such asTaiwan, South Korea and Malaysia.NICs have been characterised byincreasing average annual incomesand producing relatively cheap exportgoods due to low labour cost

NGO — non-government organisationNICs — see Newly Industrialising

Countriesniche — the space that an organism

inhabits and to which it is adapted. Aniche provides the food for theorganism as well as the microenviron-ment that ensures its survival.Environments such as the Tropicsprovide a greater range of niches thansay deserts because of the abundantenergy in the Tropics. Should theniche be disturbed in some way suchas by fire, the invasion of a competitor,or a natural change such as increasingaridity, the niche for an existingorganism may be destroyed andanother organism may occupy thisnew environment or niche to which itis adapted

nickpoint — part of the long profile ofa stream that changes its gradientrapidly. For example as a river erodesits bed it may produce what is called agraded profile whereby erosion anddeposition equal each other at any onepoint. However if a more resistantbedrock is encountered the river maycascade over this forming a waterfalland erode its bed further downstream. Similarly a nickpoint may alsooccur where the stream changes its

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long profile due to local uplift orsealevel change

NIEO — see New InternationalEconomic Order

Nitmiluk National Park — that area ofthe Northern Territory that includesKatherine Gorge

nitrogen cycle — the circulation ofnitrogen through the biophysicalenvironment mainly as a result ofliving organisms. Inorganic nitrogen(in the atmosphere) is taken up byplants, which in turn are eaten byanimals and eventually returned to thesoil and water. Nitrogen fixation leadsto nitrogen being taken from the airand being available to plants. Some bacteria return nitrogen to theatmosphere

nitrogen fixation — a reaction betweennitrogen and the atmosphere whereatmospheric nitrogen is incorporatedin a soluble compound such as waterand is available as a plant nutrient.(Legumes such as peas and beans ‘fix’nitrogen and make it available to thesoil as a fertiliser

nival — relating to snow nivation — the process of freezing and

thawing in an environment dominatedby snow — especially in glacial andalpine areas

node — a focus for any type of activity.For example towns and cities act asnodes whereby major roads andrailways focus on the urban centre;investment capital, labour, and goodsand services are drawn to the urbancentre such as Sydney, Perth, New-castle and Geelong

nomad — a term commonly used for aperson who moves from one place toanother especially in arid and semi-arid areas. For example nomadicherders such as the Bedouin whomove camels or cattle from place toplace in North Africa and the MiddleEast (see arid environment)

non-renewable natural resource —the total amount of the naturalresource is reduced as a result of itsuse. Fossil fuels are non-renewableresources because when oil, coal or

natural gas as well as various mineralsare consumed the total amount of thatresource is reduced. The consumptionof non-renewable natural resourceshas been increasing at an increasingrate, especially in developed countriesin order to provide power fortransport and industrial growth

NPWS — National Parks and WildlifeService NSW, Australia

nuclear winter — a theory that suggeststhat a thermonuclear war would leadto global cooling of over 20ºC. The resulting fires, smoke and otherparticulates in the atmosphere wouldhave the effect of shielding the Earth’ssurface from sunlight — therebycooling the atmosphere, the oceansand the land. This, in turn, would leadto a major global extinction event

nucleated settlement — a compactrural settlement consisting of groupsof buildings in close proximity. Thesemay be small farmsteads or homes andshops around a central point such as achurch or community centre. More broadly a nucleated settlement isany dense settlement in an areasurrounded by a low density hinter-land. In many cases nucleatedsettlements locate at a point thatprovides the greatest advantage for thesettlement – such as at the junction oftwo roads or two rivers for ease oftrade, or on a top of a hill for defence

nuée ardente — a cloud of very hot gasand ash that moves downslopeproduced during some volcaniceruptions. The ash is later depositedto form what is called tuff

nunatak — a mountain peak protrudingthrough an icecap. In Antarctic, forexample, the two kilometre icecapcovering many mountains has thepeaks of some mountains risingthrough and above the icecap (eg thepeaks of the Transantarctic MountainRange in Antarctica)

Nunavut — a new territory in northernCanada created 1 April, 1999 when theNorthwest Territories were dividedinto two. Nunavut means ‘one land’

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oasis — a fertile or well-watered area within adesert with animal andplant life sustainedthroughout the year

obsidian — volcanic glass formed from lava that has cooledextremely quickly

occluded front — because a cold airmass moves faster than a warm airmass the passage of a cold front tendsto move forward and replace warmerair. As the warm air is less dense thanthe cold air the cold air tends to‘squeeze’ (or force up) the warm airahead of it to higher altitudes. The cold air mass may then ‘catch up’with cold air ahead of it. Where thesetwo cold fronts meet leads is called anoccluded front — the result of theprocess called occlusion

oceanic crust — that part of the Earth’scrust under the oceans. It is muchthinner than continental crust, atabout 3 kilometres thick (see sial,sima)

ocean trench — a deep submarinevalley that forms along the line whereone lithospheric plate plunges underanother in what is called a subductionzone. Ocean trenches can be seenaround the word especially aroundthe Pacific Ring of Fire. Ocean trenches are the sites of manyactive volcanoes and severeearthquakes. The Mariana Trench,east of the Philippines, is the lowestpoint on the Earth at 11,022 metresbelow sea level – where the PacificPlate moving west is plunging underthe Philippine plate (see figure 17,continental drift, plate tectonics)

OECD — Organisation for EconomicCooperation and Development.Member countries are Australia,

Austria, Belgium, Canada, CzechRepublic, Denmark, Finland, France,Germany, Greece, Hungary, Iceland,Ireland, Italy, Japan, Luxembourg,Mexico, Netherlands, New Zealand,Norway, Poland, Portugal, SouthKorea, Spain, Sweden, Switzerland,Turkey, United Kingdom, USA

okta — a unit for measuring total cloudcover. One okta indicates that oneeighth of the sky is covered by cloud;three quarters of the sky is indicatedby six oktas. Oktas are sometimesindicated on synoptic charts

old growth forests — forest dominatedby mature trees that show little or noevidence of human disturbance suchas logging and road building. Old growth forests such as theEucalypt forests in southeast NewSouth Wales and the rainforests innorth Queensland have been the focusof many disputes; for example

i) loggers wanting timber forbuilding construction inAustralia

ii) multinational companies want-ing woodchips as a cheapsource of timber product and

iii) conservationists wanting toretain these to provide naturalhabitat as well as a resource forfuture generations (seewoodchipping)

old population — the population of acommunity, such as a country, isconsidered ‘old’ if the proportion ofyoung people ( under 15 years of age)is less than 30% of the total populationAND the proportion of older people(over 65 years old) is greater than 6%of the total population (see ageingpopulation)

oligopoly — an industry in which a fewfirms control the production process(see monopoly)

o


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oligotrophic — poorly-nourishedwaters such as some lakes and rivers

Olympic Dam — uranium mine 200kilometres north of Port Augusta,South Australia. Beginning operationsin 1988 it is also known as RoxbyDowns

omnipolis — an urban area dominatedby shopping malls. Super-regionalcentres try to reproduce facilitiestraditionally available in the centralbusiness district. The omnipolis caters for a 'globalculture' as well as a tourist market.The local 'sense of community'declines the larger the mall. The focusof the super-regional centre is typicallyon recreational shopping andentertainment rather than traditionalretail services

omnivore — organism that eats bothvegetable material and meat. Humansare omnivores

Onchocerciasis — river blindness; verycommon in West Africa such as inBurkina Faso. Onchocerciasis iscaused by people being bitten by ablack fly, with tiny worms skeweringinto the body and attacking the backsof the eye (see Schistosomiasis)

OPEC — Organisation of PetroleumExporting Countries

open cut mining — also called stripmining; occurs when material such ascoal or ores such as gold and bauxiteare mined by removing the soil over-burden (Figure 43 colour). Often seams are subjected toexplosions to make them accessiblefor collection and transport. Open cut mining is used when thematerial is not in rich veins – in thesecircumstances, direct shaft mining isundertaken

opportunity cost — the alternative thatis foregone (or given up) as a result oftaking up an alternative option. For example the construction of anelevated walkway across sand dunesmay incur an opportunity cost of notbeing able to begin a dune re-vegetation program

optimum range — where an organismlives within only a small prt of theirrange of tolerance. The organism cansurvive outside this range but theorganism would be under stress.Conditions of temperature, moisture,food source and predation ensuresurvival

organic farming — farming without theuse of artificial fertilisers, herbicidesand pesticides. Vegetable growing iscarried out using inputs such a directrainfall and sunshine. This method ofproduction can be described as labourintensive

orogeny — or orogenesis; the processof mountain building. Mountains aretypically formed at plate margins suchas fold mountains at sites of platecollision and volcanic mountains atsubduction zones. The types andcharacteristics of mountains areinfluenced by six main factors:

• rock sequences such as sedimen-tary deposits in geosynclines

• structural deformation such as theamount of folding or faulting thathas occurred in a sequence

• metamorphism, ie the changedtemperature and pressure rocksare subjected to that can lead tochanging mineralogy and rock type(such as shale to slate)

• igneous activity such as the up-welling of magma forcing land torise, including the upwelling ofmagma in subduction zones and athot spots

• erosion or the various forces ofdegradation wearing away moun-tain landforms

• isostacy as the land ‘rebounds’following the removal of overlyingmaterial by erosion (see fault, fold,plate tectonics, sedimentary rock,volcano)

orographic rainfall — rainfall thatresults from orographic uplift. Forexample as air moves from the seatoward the land the air cannot passthrough higher land so it rises up to ahigher altitude.

aryewhy

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As the air rises, it cools and mayeventually rain. Rain falls on thewindward side of the barrier (ie theside from which the wind comes). On the other side of the barrier (onthe lee or leeward slope) conditionsare much drier (see precipitation,figure 50)

orographic uplift — air that is forced torise as a result of meeting a barrier.

orthogonal — imaginary lines that aredrawn at right angles to wave crestsshowing the concentration of waveenergy. These lines showing energydistribution are concentrated onheadlands and less so in bays andalong beaches. This is one explanation for majorerosion along cliffs and depositionalong beaches

orthophoto map — a composite mapincorporating imagery from aerialphotography as well as overlyingcontour lines. Although not totally accurate inlocating features they do provideinsight as to relationships between airphoto images and the topography asindicated by overlain contours (seefigure 69 colour)

Our Common Future — ‘Our CommonFuture’ is a publication that arose outof an international meeting held bythe WCED and published in 1987. Ithad the aim of raising globalconsciousness as to the plight ofglobal natural resources as well as thedisparity in the quality of life of peoplearound the world. It begins by saying: ‘The Earth is onebut the world is not. We all depend onone biosphere for sustaining our lives.Yet each community, each country,strives for survival and prosperity withlittle regard for its impact on others. Some consume the Earth’s resourcesat a rate that would leave little forfuture generations. Others, manymore in number, consume too littleand live with the prospect of hunger,squalor, disease and early death.’ It concludes: ‘The commission is

convinced that if we can make solidprogress towards meeting theseprinciples the next century can offer amore secure, more prosperous, moreequitable and more hopeful future forthe whole human family’ (see WorldCommission on Environment andDevelopment)

outstation — an Aboriginal settlementdeveloped in more remote areas thantownships and reserves that they wereaccustomed to. Since the early 1970s some Aboriginalgroups have decided to live inindependent communities, innorthern and central Australia,attempting to retain traditions anddevelop a more independent lifestyle.These communities have come to beknown as homeland centres oroutstations

overbank flow — river flow that leavesthe main channel reaching thefloodplain as in a flood

overland flow — the movement ofwater across the surface of the land.Water flows across the surface becausethe land has become saturated. Therate of precipitation has exceeded therate of infiltration (see Hortonoverland flow)

overurbanisation — where cities indeveloping countries experiencepopulation growth that outstripseconomic growth and leads to majorsocial, environmental and economicproblems

oxbow lake — a river landform thatforms when a section of a meanderingstream is cut off from the mainchannel – also called a billabong or ameander cutoff (see meander)

oxidation — a process of chemicalweathering. The absorption by amineral of an oxygen atom. Oxidationis common in rocks containing ironminerals. In soils iron minerals areoxidised when they absorb oxygendissolved in water passing through thesoil. An example of oxidation can beseen in the rusting of objectscontaining iron

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ozone — a form of oxygen that consistsof thee oxygen atoms (as opposed tothe normal 2 needed for people tobreathe). In the lower atmosphereozone is toxic to people especiallythose with asthma. Ozone (O3)however is beneficial to life on Earthwhere it is concentrated in thestratosphere, 22–25 km altitude. Hereit filters damaging ultraviolet lightfrom the Sun

ozone hole — a region in thestratosphere (22–25 km altitude)

where there has been a thinning ofozone concentration. Initially detectedover Antarctica it has spread to be oversouthern Australia and southern SouthAmerica and more recently a hole hasdeveloped over the Arctic. It is thoughtthat the ozone hole has developed as aresult of the excessive use of chlorinecompounds in refrigerants, foampackaging and aerosol cans. Theresultant CFCs attack ozone therebymaking it thinner and less able to actas an umbrella against insolation (see

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Pacific Rim — thosecountries that borderthe Pacific Ocean suchas Japan, the Philip-pines; USA, Peru andChile

Pacific Ring of Fire — a line of volcanicand earthquake activity around theedge of the Pacific Basin (Figure 44). It includes the area from the AleutianIslands in the north, south through SWUSA and Central America and alongthe Andes mountain range in SouthAmerica; as well as the area north fromNew Zealand, through the Solomonand Indonesian islands and norththrough the Philippines and Japan.In these areas, such instability is theresult of major plate movements atsubduction zones (see continentaldrift, plate tectonics, plates, volcano)

padi (also paddy) — i) rice; ii) the smallfield in which rice is traditionallygrown in Asia (see padi field)

padi field — a small field in which riceis grown in flooded fields typically inAsia (see intensive farming/agriculture/land use, padi)

pahoehoe — solidified lava with asmooth or ‘ropy surface.’ This is verydifferent from the sharper, moreangular surface of aa lava (seevolcano, extrusion)

pallid zone — the white or very palesoil horizon within a weathered soilprofile. It often indicates that strongleaching has occurred with only finegained clays remaining in the horizon(see chemical weathering, weathering)

palynology — the study of pollen grainsused to identify particular vegetationspecies. Such analysis is also used todetermine earlier climatic conditions.For example, from the study ofsediments, pollen indicating rainforest

type plants in a present aridenvironment suggests that the climatewas much wetter and possibly warmerthan today (see figure 12)

pampas — a name for the grasslands ofArgentina, South America (seesavanna)

pan — see hardpan and podsolPanama Canal — an 82 kilometre canal

opened in 1914 in Panama linking theAtlantic and Pacific Oceans. The canalallows shipping, both for recreationand international trade, to use thisroute rather than the much longerroute south around Cape Horn (SouthAmerica)

pandemic — a worldwide or continent-wide outbreak of an infectious disease.It is an epidemic that affects manycountries at once

Pangaea — the name given to the singlecontinental land mass of approx-imately 250 million years ago thateventually split into two ‘super-continents’ (200–180 million yearsago) – Laurasia comprising present-day northern hemisphere continentsand Gondwana comprising thepresent southern hemispherecontinents, and India (see continentaldrift)

parallel — a line of latitude; eg the 50°Sparallel of latitude (see longitude)

parent material — the material fromwhich soil material has developed.Parent material may be the observedbedrock. A soil may form from theweathering of sandstone bedrock. Inthis case the sandstone is the soil’sparent material

Paretian optimum — originally used ineconomics (by the economist Pareto)this is a concept that states that, withuniform incomes and stable levels of

P


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technology in an efficient economy, itis not possible to increase oneperson’s or group’s consumption orsatisfaction without reducing that ofanother person or group. This is similar to the concept of thesustainable yield of naturalresources. As a result of the

consumption of natural resourcesthere is an impact of suchconsumption on either theenvironment or on individuals. TheParetian optimum is that point whereit is not possible to increase the leveland rate of consumption of a resourcewithout having an adverse effect on

Figure 44 � Pacific Ring of Fire

Source: T.H. Van Andel, New views on an old planet: a history of globalchange,

Eurasia

Pacific

Antarctica

Nazca South

Africa

Australia

NorthAmerica

ArIn

Phil

JF

Cocos

aryewhy

Distribution of earthquakes and volcanoes (A) � note the highconcentration around the edge of the Pacific Plate � (Ar=Arabian Plate;

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other aspects of the environment or thecommunity

parna — clay deposits including somesand that makes up individual dunesor sheets of sand — typically deflatedfrom unvegetated arid land and fromthe dry beds of salt lakes in Australia(see deflation)

pastoralism — a form of agriculturethat uses large areas of land for thegrazing of livestock such as beef cattlewith little or no cultivation of crops(see commercial agriculture, extensivefarming/agriculture/land use

pasture — grassland used for thegrazing of cattle

Patagonia — an arid area of south andsoutheast Argentina (South America)

Paterson’s Curse — a plant, also knownas Salvation Jane. Paterson’s Curse wasintroduced into Australia from theMediterranean region in the 1800s. Ithas become a weed as it out competesnative pastures and has invadedgrazing lands that were used as a foodsource for cattle

pathogen — a substance such as anorganism that causes disease

patterned ground — a general termused for an array of shapes that occuron the land’s surface as a result of anumber of processes such as frostaction. Typically soil particles aresorted according to grain size withshapes such as circles, stripes andpolygons formed depending uponslope, soil type and even theavailability of moisture. Various typesof patterned ground are common inperiglacial areas

PCB — see polychlorinated biphenyl ped — a natural soil aggregate

consisting of many soil particles. Pedscan be arranged in a number ofpatterns including blocky peds 1–2 cmdiameter, and columnar peds whichare approximately 5 cm long

pedal — soil material showing anorganisation of soil particles intodiscrete aggregates. A pedal soil mayshow blocky peds. Soils with a clayeyor loamy texture are often pedal insome form (see apedal)

pediment — an extensive weatheredrock surface (hundreds of km2)subjected to various types of physicalweathering and eroded by deflationas well as a combination of rill erosionand sheet erosion. Steeper slopes arebacked by a steep scarp. A concave-upward slope extendsbeyond the scarp to an extensive areaof very low gradient (as low as 1° to2°). Such slopes are common in farwestern NSW, and northern SouthAustralia, Australia. Where a number of adjacent pedim-ents coalesce the broad flat rocky plainis called a pediplain

pediplain — see pedimentpedogenesis — the formation of soilspedology — the scientific study of soils

and soil material – their character-istics, distribution and processes offormation

pelagic — relating to the open oceanPenck, W — whereas W.M. Davis, in his

cycle of erosion, promoted the theoryof slope decline leading ultimately topeneplain, Walther Penck advocatedthe idea of slope retreat. In this modelit was suggested that slopes erodedbackwards, rather than downwards.Relatively steep angles resultedleading ultimately to a gently slopingeroded bedrock surface called apediment

peneplain — an extensive area of lowelevation and relief approaching sealevel as a result of erosion. A peniplainis a result of what W. M. Davissuggested was the end product of alandscapes ideal (uninterrupted) cycleof erosion (see erosion)

peninsula — a narrow piece of landsurrounded on three sides by water;eg Cape York Peninsula

Pepenadores — Mexico City’s poorestpeople who live on and feed from citygarbage dumps

percentage change — a mathematicalmeasure indicating by whatproportion (percentage) of the initialfigure that a value has increased ordecreased over a period.

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For example a value of 20 shows a100% increase if it increases to 40; avalue of 50 increasing to 150 shows anincrease of 200%

% change =the difference between the two values

the original numberx 100

eg in 1980 there were 5000 people living inSunhillow;

. . . but in 2002 there were 6500

percentage change = 1500 x 1005000

Therefore there has been a 33%increase in population numbers

perched water table — a water tablelocated above the normal water table.Water collects above a relativelyimpermeable layer of rock strata.Below this is an unsaturated layerfollowed by the main water table (seeimpermeable/impervious)

perennial — i) plants: live formore than one year ii) streams:flow all year round (seeephemeral, intermittent)

periglacial — a term used todescribe those conditions andlandforms bordering on, orsimilar to, those of ice caps. Aperiglacial climate besidesbeing arid (dry) hastemperatures below 0°C for atleast 6 months of the year. Periglacial processes aredominated by freeze-thawaction where rocks are brokenup as a result of the pressuresexerted by ice crystalsexpanding as water freezes. Solifluction on hill slopesresults. Here soils becomesaturated with water as groundice melts and the top layers ofa slope slowly move downslope under the influence ofgravity. Areas of tundra have beendescribed as periglacialbecause of the coldtemperatures.

Similarly high altitude mountainousareas can be described as periglacialbecause similar processes operate inthese cold environments (seemountain, physical weathering)

perihelion — at approximately 3 January each year the Earth and Sunare at their nearest point (seeaphelion)

permafrost — permanently frozen soil.Permafrost is common in high latitudeareas such as Canada, NorthernEurope and Eastern Russia

permeability — a measure of thecapacity of a rock or soil to transmit afluid such as water – hence highlypermeable and low permeability (seeimpermeable/impervious)

personal quality of life index — ameasure of development/ personalwell-being of a nation and individuals.The index uses three indicators: lifeexpectancy, infant mortality and

Figure 46 � The Phosphorus Cycle: flowsbetween sources and sinks Australia-wide

Source: Commonwealth EPA,

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literacy rate (see human developmentindex, infant mortality rate)

petrified wood — wood that has beenturned to stone. As wood breaks downthe tissue matter of vegetation such astrees, it is slowly replaced by mineralsthat are in the groundwaterpercolating through the soil – mineralssuch as calcium carbonate and silica.These minerals eventually crystalliseassuming the shape and structure ofthe initial tree

petroglyph — a prehistoric drawing orcarving on rock (Figure 45 colour)

pH — a measure of the acidity oralkalinity of a substance such as soilor water. pH measures the number ofhydrogen ions in the substance. pH isthe negative logarithm of thehydrogen ion concentration in asubstance. pH is measured on a scaleof 0–14 on which 7 is said be neutral. A number less than seven indicatesrelative acid conditions; greater than 7 relatively alkaline conditions. Forexample a pH of 4 indicates an acidsoil — and it is ten times as acid as asoil with a pH of 5

phosphorus cycle — a majorbiogeochemical cycle of the Earthwhich describes the transfer ofphosphorus within the biophysicalenvironment (Figure 46). Part of majorgeological processes, operating overmillions of years, phosphorus accumu-lates on the ocean floor formingphosphatic rocks. As a result of Earthmovements, such as mountainbuilding, these rocks become exposedat the Earth’s surface.Phosphorus is then broken down laterto be taken up by plants and in turn byanimals and people. Birds addphosphorus to the land in the form ofguano. This occurs on the island ofNauru. Additional phosphorus is added by theinput of fertilisers and sewage which,when leached into the soil, returns tothe oceans via rivers and wetlands. The addition of phosphorus onto theland and into waterways causes serious

problems for native vegetation andaquatic life (see degradation,eutrophication)

photic zone — the surface waters ofrivers, lakes and oceans that arepenetrated by sunlight (seeeutrophication)

photochemical smog — a type of airpollution resulting from a variety ofchemical reactions between sunlightand pollutants in the atmosphere.Photochemical smog commonlyfollows the occurrence of brown hazewhen, during the mornings, gasessuch as nitrogen and carbonmonoxide are added to the loweratmosphere by car exhausts. Thesechemicals react with the more intensesunlight in late mornings and earlyafternoons to form a ‘chemical soup’in the atmosphere. This can be verytoxic to many people — such aspeople with asthma when ozoneconcentrations become very high

photosynthesis — a biochemicalprocess in plants by which energyfrom the Sun (used by chlorophyll),carbon dioxide and water are taken upby the plant. The plant produces moreorganic material and in doing so givesoff oxygen

CO2 + 2H2O light energy [CH2O] + O2

chlorophyllphotoperiodism — the response of

plants and animals to variations in therelative length of day and night eg thetiming of flowering or breeding

physical geography — a branch ofGeography concerned with thedescription and explanation of thenatural features of the Earth’s surface. It includes the study of such featuresas rivers, coasts, soils, vegetation,weather and climate. Increasingly, the focus of physicalgeography has been to provide abetter understanding of the Earth’sphysical processes such as erosion andglobal warming in order to improvethe wellbeing and quality of life ofpeople (see geography, humangeography)

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physical weathering — the physicalbreakdown of material into smallerpieces in situ. The combined action of wind, waterand temperature results in suchprocesses as abrasion, freeze-thawaction or thermal expansion. All leadto the reduction in the volume of theoriginal material (see chemicalweathering, weathering)

phytoplankton — tiny marine plants(see plankton)

pillow lava — lava that has solidifiedquickly under water and takes on theappearance of pillows (see extrusion,volcano)

pingo — a small rounded hill typical ofglacial and periglacial areas. Thepingo has grown as a result of thedevelopment of the central ice core.They are found in areas such asnorthern and central Canada andnorthern Russia (see glacier)

piping — a geomorphic (earth surface)process where throughflow isconcentrated especially along a soilhorizon boundary such as between theA-horizon and the B-horizon. Whenthe soil horizon is exposed on ahillslope, along a steep stream bank,material drains out and is depositeddownslope. This leaves a ‘hollow tube’or pipe beneath the surface. If andwhen the pipe collapses, due to theabsence of deep-rooted vegetation,gullies can form

placental — a mammal where theyoung remain in the womb for muchlonger than marsupials and for whichthere is no pouch – eg bats and variousrodents

plankton — small microscopicfreshwater and marine organisms.There are two main types; phytop-lankton such as algae andzooplankton which include such

Figure 47 � Pleistocene sea level changes

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animals as protozoa. Plankton are animportant food source in the marineecosystem. They are also important inregulating global climate. For example, plankton are importantphotosynthesisers. They take up largequantities of carbon dioxide. Howeverwith further ozone depletion planktonwill die and so take up less carbondioxide. In turn, this could lead tofurther global warming (seephotosynthesis)

plantation — a large field for growingcrops. A term commonly used for large‘estates’ in tropical and sub-tropicalareas where there is a high input ofcapital such as land, machinery andfertilisers and crops are grown forexport overseas (eg pineapple, rubber,tea) (see commercial farming,intensive farming/agriculture/ land use,monoculture)

plantation agriculture — anagricultural system engaged in thelarge-scale production of commercialcrops. Originally plantations wereestablished in developing countriesfollowing early colonisation bywestern countries especially alongcoasts and river valleys for easy exportof crops. A system of agriculture wasestablished that replaced traditionallocal food producing crops. Insteadfarms became amalgamated into singlelarge estates called plantationstypically concentrating on a singlecrop and with the use of scientificmethods and close management. Non-food crops included rubber trees andcotton. However many food cropswere not for local production but forexport to markets in the developedworld — eg tea, oil palm, cocoa,pineapples and sugar cane

plant succession — the progressivenatural development of vegetationwhere one vegetation community issuccessively replaced by another.Primary succession begins at areas thathave not been previously occupied byvegetation (eg a rock surface, a sanddune). Secondary succession occurs inareas where the present vegetation has

followed the destruction of an earliervegetation community such as by fireor land clearing due to urban sprawl

plate tectonics — the science studyingthe movement of plates over thelithosphere as a result of sea floorspreading. This study has developedsince the 1960s following theconfirmation of the theory ofcontinental drift (see Wegener, A)

plates — pieces of the lithosphere onwhich ride the continents. There are16 major plates the largest being thePacific Plate. Australia (includingTasmania) and the island of NewGuinea are on the one plate. ThisAustralian Plate is drifting north atapproximately 7cm a year (seecontinental drift, figure 44, platetectonics)

plateaus, plateaux — a large area ofelevated land of uniform height. Theland may extend for hundreds ofsquare kilometres. Australianexamples include the WoronoraPlateau south of Sydney, NSW orthousands of square kilometres suchas the Arnhem Plateau in the NorthernTerritory

playa — a dry salt lake typically found inarid and semi-arid environments suchas in Western Australia and SouthAustralia (see arid environment,salina)

Pleistocene Epoch — a period in thehistory of the Earth with markedtemperature fluctuations (Figure 47).Within this period (sometimes called“the ice age”) there were major falls oftemperature called glacials withwarmer interglacial phases between(see Quaternary Period)

plenilune — the time of the full moonplucking — a process of glacial erosion

describing the removal of discreteblocks of bedrock. Weathering such asfrost wedging weakens joints andbedding planes in bedrock which areplucked or pulled out by the action ofmoving ice

plunge pool — a pool at the base of awaterfall marking a nickpoint in thelong profile of a stream

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plural society — a society in which twoor more distinctive cultural groups liveside-by-side with no central politicalbody governing the group as a whole.Religion, language and customs arepractised by the individual groups

pluvial — a period of wetter conditionsas a result of either increasedprecipitation or decreasedevaporation. This is often related tohigh lake levels in arid areas duringthe Pleistocene

pluviometer — an instrument formeasuring rainfall in millimetres

pneumatophores — these are thevertical aerial roots of vegetation suchas mangroves that protrude fromlarger roots under the ground. Wherethe roots are covered with water orcovered during high tide.Pneumatophores allow the mangroveto take in carbon dioxide. They alsoallow the plant to give off waste hassuch as hydrogen sulphide (or rottenegg gas)

podsol — a deep, sandy slightly acidsoil. Developed often in stabilisedsand dunes podsols reflect a history of

vertical processes. Leaching ofminerals and eluviation of fineparticles produce a distinctive soilprofile. The weak humic acidproduced at the surface from thedecay of vegetation leads to adistinctive shallow A-horizon. Belowthis horizon, however, minerals andfine particles have been transportedthrough the profile leaving a bleachedor white horizon which is commonlycomposed of individual quartz sandgrains. Minerals such as aluminiumoxide, stripped from the upper A-horizon, are often illuviated in thelower B-horizon. In some instances a‘hardpan’ or indurated horizon,develops. This horizon is an orange-brown hard, brittle layer that isdifficult for roots to penetrate andsometimes needing a hammer tobreak (see illuviation)

point bar — a deposit of sediment suchas sand on the inside bend of ameandering river. Rivers flow moreslowly on the inside of meander bendsbecause of the slowing effect offriction as water rubs against the bankof the stream. As the river slows in

Figure 48 � World Population Growth

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velocity its competence isreduced; the river thendeposits the heavier sedimentthat it can no longertransport (see deposition ,figure 25)

point source — the specificlocation of a substanceentering a drainage system(stream)

Polar cell — part of theatmosphere’s generalcirculation, the Polar cell islocated in the high latitudesover each pole. In theSouthern Hemisphere, colddense air over the South Polesinks. It meets the surfaceand then flows north toapproximately latitude 60°S.At this point it meets warmer,less dense air coming fromthe north. When the twobodies of air meet the lessdense air rises through thetroposphere. Some of this airthen moves south again atabout 8 km altitude. The aircools, becomes denser and sosinks again at the Pole. Thiscirculation of air is known asthe Polar cell (see Generalcirculation, the Hadley celland the Ferrel cell). This coldsinking air contributes to theextreme aridity of the polarregion (see atmosphere,Ferrell cell, figure 26, Hadleycell)

polder — flat low-lying landbelow sea level along thecoastal areas of TheNetherlands that have beenreclaimed from the sea.Dykes have been constructedto hold back the sea as theland has been drained. Thisprovides additional land foractivities such as agriculture

polychlorinated biphenyl — agroup of chlorinatedhydrocarbons that have beenwidely used in industry forexample as insulators in

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Figure 49 � Population Pyramids

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transformers. The use of PCBs hasbeen severely reduced as a result ofthe awareness of their toxicity topeople and the environment generallyas well as their prolonged lifespanwithin the environment

Polynesia — that area of islands to theeast of Australia such as Tonga, Samoa,Hawaii and New Zealand (seeMelanesia, Polynesia)

Polynesian — tall, brown-skinnedpeople with dark, straight or wavy hairwho occupy islands to the east ofAustralia (see Melanesia andMicronesia)

pool — a long, deep and slow flowingsection of a river. Pools are commonlyfound on the inside of meander bends(see figure 25, riffle)

pool-riffle sequence — a series of deepsections (pools) and shallows (riffles)along the course of a river. Deep pools

(with a low water velocity) arecommonly found on the inside ofmeander bends and riffles (with ahigher water velocity) along thestraight reaches of a stream. It hasbeen demonstrated that pools areseparated by lengths equivalent to 5–7channel widths. However this can vary widely. Forexample local field studies have shownthat in some instances ‘long pools’ canalternate with ‘short pools’ with ‘longpools’ separated by as much as 10channel widths and ‘short pools’separated by as little as three channelwidths. Pool-riffle sequences are acommon bedform of both straight andmeandering streams as rivers adjust tochanges in discharge and sedimentload

Pope’s Line — a line drawn in 1498north-south through South America as

Figure 50 � Types of precipitation: orographic, frontal and convectional rainfall

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a result of tension between earlycolonisers Portugal and Spain. These countries wanted the perceivedwealth of South America. So the Popedrew an arbitrary line that almostfollows the 55°W meridian oflongitude. All the land to the east of this line wasgiven to the Portuguese; to the westwas for Spain

population — a group of individualorganisms of the same speciesoccupying the same habitat (Figure48). For example a penguin colony;the human race

population density — the number ofpeople per unit area of land. Forexample, if there are 5 people in asquare kilometre of land thepopulation density is said to be 5people per square kilometre (or 5people/km2); 100 people in 50 squarekilometres of land = 2 people/km2. Population density tends to be high inurban areas (eg 200/km2) and lower inrural areas (eg 10/km2)

population pyramid — a bar graph(histogram) showing via a series ofhorizontal bars the number orpercentage of the population in a

Description of Common Types of Precipitation (hydrometeors)

PRECIPITATION DESCRIPTIONDrizzle Droplets less than 0.5mm diameter; intensity usually less than

1mm/hr; very small numerous droplets that seem to float in theair following air currents. Mist is often interchanged with drizzlealthough it more specifically refers to a condition of reducedvisibility due to microscopic water droplets in the air

Rain Droplets greater than 0.5 mm diameter, intensity generally morethan 1.25 mm/hr. Larger but fewer droplets than drizzle so thatthere is generally less reduction in visibility except for theheavier rainfalls

Snow White or translucent ice crystals often agglomerated into theform of flakes. Size of flakes depends principally on watercontent and amount of moisture surrounding the crystal

Sleet Transparent, solid grains of ice formed from freezing of rain orslight melting and refreezing of snow as it falls. Sometimesconfused with small hail

Hail Balls or lumps of ice often with concentric layers of clear andmilky ice, diameter greater than 5mm. If the diameter is less it iscalled ice pellets or snow pellets

Virga Water and ice particles falling from clouds but evaporatingbefore reaching the ground

Rime White or milky granular deposit of ice formed by rapid freezingof supercooled water droplets hitting an exposed surface

Glaze Coating of clear smooth ice on exposed objects by the freezingof a film of supercooled water deposited by rain, drizzle or fog.Denser than rime

Dew Water condensed on objects near the ground whosetemperatures are above freezing but below dew point. Frostoccurs if temperatures are below freezing. White dew is frozendew resulting from temperatures falling below freezing after dewis formed

Modified extensively from Maher, J.R., Climatology: fundamentals andapplications, 1974 p.48

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particular age group cohort — seeFigure 49. The shape of the population pyramidprovides an idea of the character of thepopulation. For example indeveloping countries the base of thepyramid (ie less than 15 years old)tends to be relatively wide (eg due tohigh birth rates). However, the top(greater than 60 years) tends to bevery narrow (eg due to high deathrates and low life expectancy)

porosity — a characteristic of rock orsoil indicating the extent to which itcontains spaces (pores or voids)within it — strictly a measure of thepercentage of the total volume of rockor soil that is pore space. Limestonemay be very porous; granite is not

post-Fordism — workplace practicesand modes of industrial organisationthat have developed since the mid1970s featuring more flexible methodsof production, such as just-in-time orsubcontracting

post-industrial city — a city with asubstantial proportion of workersengaged in the quaternary sector

postmodernism — a world in whichindividual entities are constructed(and reconstructed) from manycultural sources, where ethics andmorality are developed throughdialogue and choice, where nodominant style dominates art andculture and, where people feel free tocross cultural borders or cling to tribalidentities in a globalised society

post-structuralism — a philosophicalmovement that tends to reject therational ideas of science and grandstories of social evolution. It is aneconomic development of the modernera and is open to a wide range ofviews of social enquiry

prairies — grassland typical in centraland western USA. Much of the prairieshave been taken over by extensivefarming such as cattle grazing (seeextensive farming/agriculture/landuse)

Precambrian Era — a period ofgeologic time before the CambrianPeriod. The Precambrian Era makes upthe great bulk of geologic historyextending from the formation of theEarth, 4.5 billion years ago untilapproximately 570 million years agoafter which there was an explosion inthe diversity of life from the CambrianPeriod until the present (seegeological time scale, figure 27)

precious metal — a metal of higheconomic value such as gold and silveroften used for and in jewellery

precipitation — the process by whichwater returns from the atmosphereto the surface of the Earth in the form of rain, hail, sleet, snow, dew etc(Figure 50)

precis — a summary; a precis map inGeography is used to summarise asingle feature in an area eg vegetation,landforms, rivers

pressure gradient — a term used todescribe the rate of change in pressureacross an area. A steep pressure gradient occurswhere there is a rapid change inpressure; this can be shown where theisobars are close together. In this casewinds tend to be strong. A gentle or small pressure gradientshows little change in pressure over anarea so isobars are far apart and thewinds are weak

primary data — information that is first-hand and has not been processed orchanged eg that collected throughfieldwork such as surveys and fieldmeasurements

primary productioni) the production of raw materials

provided by nature such as themining of coal and iron ore, theraising of beef and dairy cattle andthe growing of crops such as wheatand sugar cane

ii) a measure of the energy or matterpotentially available to hetero-trophs. Estimates of global (net)primary production vary greatly

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but some are:Total volume – 180 x 109 dry tonnes ofdry matter

Ecosystem Net Primary Production

(grams / m2 / year

coral reefs 2500

tropical rainforest 1800

temperate forest 1250

open ocean 125

desert scrub 70

primary research — research under-taken that generates new informationmainly from original fieldwork, suchas measuring and recording. Similarly describing the changingpattern of a river channel, conductingan interview or implementing acommunity questionnaire are exam-ples of primary research – rather thanresearch that relies on data alreadycollected and collated such as innewspapers or from statistical tables(see secondary research)

primary sector — that sector of theeconomy concerned with agriculturalproduction and mining

primary succession — see plantsuccession

primary treatment — the first stage inthe treatment of sewage to removelarge solid objects by screens andrelying on the settling of sediment. A process of flocculation is usedwhere an agent is used (called Alum),placed in the sewage treatment pond,attracting suspended particles to itand then settling out later to beremoved (see secondary treatment,tertiary treatment)

primate city — a city that is ranked 1 inan urban system (eg in a country) andis far bigger in terms of populationthan the second ranked city. Many African, central and SouthAmerican and Asian cities are primatecities (eg Mexico City, Kinshasa, Lima,Jakarta and Bangkok). Countries with this characteristic are

said to display a degree of primacy(see binary pattern, rank size, figure57)

primates — a group of mammals thatfirst appeared more than 60 millionyears ago and which include lemurs,monkeys, apes and humans

prime meridian — the line of longitudeat 0° where other meridians lie eitherto the east or to the west (also knownas the Greenwich Meridian)

processing — see manufacturingProcoptodon — an extinct giant

kangaroo in Australia (up to threemetres tall). The Procoptodon was part of themegafauna that roamed Australiaapproximately 80,000 years ago

producer services — services that aresupplied to business or government(for example specialised legal orfinancial services) rather than directlyto individual users of commercialservices. Producer services are used todetermine world city status

property rights — the legal title to land(ownership). Property rights arelegally enforceable and can betransferred such as through the sale ofproperty (see freehold tenure, landtenure)

proportional representation — asystem of electing members ofparliament whereby the number ofelected members is proportional tothe percentage of the total vote wonby the party

proportional symbols — symbols usedon a map the size of which areproportional to the value theyrepresent. Symbols may take a variety of forms.For example if trying to show that thepopulation of City (B) is half that ofCity (A) then City (A) will have asymbol twice as large as that of City(B). However it is not as simple as this.Often strict formulas have to be usedwhen drawing proportional symbols.For example if showing population bycomparing the size of proportionalcircles City (A) will not have a circle

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twice as large as that of City (B); this isbecause it is the area of the circles thatneed to be proportional. To calculatethe area of proportional circles:

i) obtain the data (eg 100, 1000,1500 people)

ii) find the square root of eachnumber (in this case 10, 32, 39)

iii) convert to millimetres (eg 1mmrepresents 2 people)

iv) this gives a scale for the radius ofthe circle

v) draw the scale and key on themap

vi) draw the circles on the map witha pair of compasses

There are many different types ofproportional symbols that can be usedsuch as circles, rectangles andtriangles; these can even be donethree dimensionally

protocol — a formal agreementbetween parties defining proceduresand courses of action. The MontrealProtocol is an example

Przewalski’s Horse — the only wildhorse left in the world discovered inMongolia over 100 years ago. Now found only in zoos, it is a speciesunder serious threat of extinction

psammosere — plant succession in asandy environment such as on a sanddune

psychrometer — a type of hygrometerthat measures relative humidity. Apsychrometer measures thetemperature of a ‘wet bulb’ and thetemperature of a ‘dry bulb’ andfollowing a particular procedurerelative humidity of a local site can bedetermined

Ptolemy (Claudius Ptolemaeus) — aGreek geographer and philosopherwho, approximately 2200 years ago,promoted the idea that the Earth was

the centre of the universe. His ideasheld sway for 1500 years until provenincorrect

public goods — those items or goodsowned collectively by the communitysuch as parks, roads and libraries.These are typically provided bygovernments as part of the smoothand efficient functioning of thecommunity

public land — land owned or held bythe government

pueblo — a nucleated village or town inthe altiplano region of Bolivia. The buildings consist of mud-brownadobe houses with clay-tiled roofs (seenucleated settlement)

P-wave — a seismic wave within theEarth generated by an earthquake dueto movement in the Earth’s crust orupper mantle. Primary waves travel relatively slowlybut they do pass through the Earth’score (see S-wave)

pyramid of biomass — a concept usedin ecology that recognises that, for an-imals at least, there is a progressivedecrease in biomass along any foodchain (from lower to higher trophiclevels)

pyramid of energy — because ofproblems associated with thepyramids of numbers and thepyramids of biomass many ecologistsprefer to use pyramids of energyutilised by each feeding group persquare metre per annum. Pyramids of energy highlight the factthat the use of energy in any feedingstage decreases along the food chain

pyramid of numbers — a concept usedin ecology that recognises that, foranimals at least, there is a progressivedecrease in the number of speciesalong any food chain (from lower tohigher trophic levels)

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negedic


quadrat — a small squareframe (eg 30cm x 30cm;1m x 1m) used tosample a small area ofland for such things asvegetation, organisms,

and soils qualitative — subjective or personal

judgements made quantitative — relating to the use of

data such as numbers and datesquaquaversal — facing in all directionsquartz — SiO2 (silicon dioxide); the

most common mineral in sandstone.Although sand is a sediment of aparticular diameter (ie 0.06 mm–2 mmdiameter) the commonly referred to‘sand’ is considered as the mineralquartz. Other darker minerals mayform sand as on the dark sandybeaches formed from volcanicsediment

Quaternary Period — a geologicalperiod in Earth history. TheQuaternary Period began approx-imately 2 million years ago and isdivided into two shorter periods – thelong Pleistocene Epoch extendingfrom 2 million years ago to approxim-ately 10,000 years ago and theHolocene Epoch 10,000 years ago tothe present (see figure 27)

quaternary sector — that part of theeconomy involving the processing anddistribution of information. Thoseemployed in the quaternary sector aretypically ‘white-collar workers’ such as

those involved in education,government, the legal system as wellas those involved in computerinformation processing and research.The quaternary sector is part of thelarger tertiary sector. The tertiarysector involves people providingservices — but services that involvephysical products such as a bakerdelivering bread or a hairdressercutting hair. However work involvedin providing services in the form ofinformation belong to the quaternarysector. The tertiary sector has beendivided up in this way because of theenormous growth in this sector sincethe early 1970s (see quinary sector)

quinary sector — primarily unpaid,volunteer work. Includes activities orservices carried out at home on a paidand unpaid basis; including childcareand handicrafts

quoquake — a term used to refer to theeffect of the combined influencescontributing to overall landdegradation (as in ‘a quoquake’). Thedevastation caused by land clearing,salinity, soil erosion etc can becollectively described as a quoquake

quota — the maximum or minimumlevel of production agreed to by aproducer and the consumer of aproduct. For example a farmer mayagree to produce a minimum yield of acrop at a set price for sale to awholesaler

Q

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rabi — the name given tothe Northwest Monsoon(winter) in India and tothe crops grown in thisseason (see kahrif)

radiation fog — low lyingcloud (fog) formed as a result of rapidcooling of humid areas close to theground. During times of coldtemperatures with clear skies and littleor no wind, such as early morningsduring late autumn-early winter, theground loses heat very quickly. The air above it is then cooled todewpoint where water vapourcondenses to form water droplets inthe air. This is seen as a low-lying fogoften being about 10–100 metres deep(see condensation, precipitation)

radiocarbon dating — determining theage of rocks using the rate of decay ofradioactive isotopes. Carbon-14 is arare isotope occurring in living plantsand animals and is continuallyrenewed in the atmosphere byincoming cosmic rays from space. When a living organism dies it stopstaking in Carbon-14 and the carbonwithin the organism decays rapidly. The relationship between the Carbon-14 and the decaying carbon is used byscientists, archaeologists andgeomorphologists to date events inrecent earth history – in particular overthe last 60,000 years (see climatechange, figure 12)

radiolaria — freshwater and marinesingle-celled animals that may be softsuch as amoeba or may have shells orskeletons. When these shells fall to theocean floor they form deep oceanoozes which ultimately form chalk

radiosonde — an instrument used formeasure atmospheric conditions suchas temperature, humidity and air

pressure in the atmosphere at highaltitudes. As a balloon transports the instrumentthrough the troposphere theinformation is recorded and is thentransmitted to a ground receivingstation

rainshadow — also known as the lee orleeward slope of a hill. A rainshadow is a circumstancewhereby one side of a hill is protectedfrom rain-bearing winds that deposittheir moisture on the exposed side ofthe hill. In the Southern Hemisphere,for example, hillslopes that facesouthward are exposed to the rain-bearing winds from the south. The north facing slopes are muchmore sheltered or protected from thewet southerly winds – so the northernslopes exist within a rainshadow. The windward slopes often receiveorographic rainfall while leewardslopes form a rain shadow

raised beach — an emerged beachrepresented by beach deposits abovepresent sea level. They are the result ofthe combined effect of sea levelchange and the rise and fall of theland. Such beaches can be tens orhundreds of metres above present sealevel

rampart — the raised seaward edge of arock platform

Ramsar Convention — the RamsarConvention on Wetlands ofInternational Importance. In 1971 aninternational conference was held inRamsar, Iran, with the aim ofidentifying and protecting the habitatsof migratory birds worldwide. There are approximately 655 Ramsarwetlands of international importance

R


aryewhy

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worldwide. Most sites are in Europewhile Australia has 40

range — i) a number that can be calc-ulated from an array of statistics togive an indication of the spread ofvalues. For example the range of the set ofnumbers 23, 19, 15, 17, 63, 24 can beexpressed as having a range of 40 (ie63–23) or can be written as 23 to 63;ii) in terms of settlement and urbanstudies the ‘range of a good’delineates the market area of a centralplace for the good – the distancepeople are willing to travel topurchase a good or service. The upper limit is the distance beyondwhich the central place no longer isable to supply that good. The rangecan therefore be considered as adistance eg 30 km. High order goodshave a large extensive range and solarge urban places tend to be spacedmore widely apart

rangelands — the large areas ofgrasslands in arid and semi-aridregions where extensive land use ispractised; the predominantagricultural use is the grazing of cattleon native pasture – in areas such assouthwest Queensland and northernSouth Australia (see arid development,extensive farming/agricultural/landuse

rank size — a theoretical characteristicindicating an inverse relationshipbetween population number and therank of an urban place. For examplethe population of the nth city is 1/nththe size of the largest city — ie the 7thlargest city will have 1/7th thepopulation of the largest city. Such apattern is very unrealistic if we look atglobal settlement patterns today (seebinary settlement pattern, primate city,figure 57)

raw material — unprocessed materials,such as coal, iron ore and timber,required in the production process

Rayleigh scattering — the scattering ofvisible light by air molecules as solarradiation enters the Earth’s

atmosphere. Blue light is selectivelyscattered creating what we see as ablue sky

red beds — sedimentary rocks with avery high proportion of iron oxidesuch as haematite. The HamersleyRanges of Western Australia aredominated by red beds. Over 2 billionyears ago the iron in the ocean watersoxidised. The subsequent iron oxidesettled and formed the vast red bedswhich have become a major economicresource with iron ore being a majorexport and input of the iron and steelindustry

red-lining — a line drawn aroundpoorer residential areas by financialinstitutions as unsuitable forinvestment

reduced (or minimum) tillage — atechnique used where soil preparationis undertaken as little as possible so asto reduce disturbance to topsoil thatcan lead to widespread soil erosion(see tillage)

referendum — a political process bywhich a change is made to theconstitution of a country. People votefor or against a proposed change. Fora change to occur in Australia it needsto be supported by a majority of votersin a majority of states

reforestation — the replanting offorests after recent clearing or as aresult of tree loss through naturalcauses

refugee — a person that leaves an areabecause of perceived danger orpersecution. This forced migration canbe the result of circumstances such ascivil or regional war, natural disastersor political unrest (see emigration,immigration, migration)

refugia — a habitat that has survivedmajor climate change, such as an iceage, enabling species and populationgroups to survive in many cases inisolation

reg — an Arabic term used to describethe flat stony desert plains of theSahara Desert in Africa. The constantwind has blown fine sand away leavinga stony surface behind (see Gibber)

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regional shopping centre — a largefree standing shopping mall of at least46,000 m2 of leased space

regolith — the thin layer of the Earth’ssurface consisting of weathered andunweathered rock and bedrock. Theregolith (including soil material) tendsto be:

� very shallow in alpine environ-ments (because of slow chemicalweathering) and shallow on theslopes of hills (because of theerosion and transport ofweathered material by agents suchas water and gravity)

� relatively deep in more humidclimates (because of the faster rateof chemical weathering) and inareas of low gradient (becausewater can remain in these areas toweather bedrock). Deposition inthese areas by agents such as waterand gravity has the effect ofbuilding up the depth of theregolith also

regression — the fall in sea level on aglobal scale). As temperatures fellduring the Pleistocene Epoch a lot ofwater was locked up as ice in glaciersas well as the Greenland and Antarcticice caps. Sea levels fell 150–200 metres(exposing more land). This drop in sealevel is called a regression (seetransgression)

regression line — this is a type of trendline drawn when one set of data isdependent upon another

rejuvenation — a process wherebyerosion is renewed. As rivers cut downand erode their beds, they continuethis until the energy of the streamcannot erode its bed any further.However, if sea level falls or the landthrough which the river flows isuplifted, more energy is provided tothe stream so it erodes its bed further.In this case the river has beenrejuvenated. Rejuvenation can lead tofeatures such as terraces and incisedmeanders

relative humidity — the percentage ofwater that the air can hold at a

particular temperature. For example arelative humidity reading of 75%means that the air is holding 75% ofthe water that it can possibly hold atthis temperature. Air can hold a great deal more watervapour at warm temperatures than atcool temperatures. Therefore arelative humidity reading of 75% at30°C, compared to a 75% reading at20°C, means that the air is actuallyholding less water at 20°C – but bothparcels of air are holding 75% of whatthey can hold

relative location — the location of apoint compared to some other pointeg 6 km from ..., Southwest of ... (seeabsolute location)

relict soil — a soil-type that exists todaybut formed under previous climaticconditions (see laterite)

relief — the difference in heightbetween two points eg 50m. Relief canalso be described as being steep,gentle etc

remote sensing — measurementwithout touching. Within physicalgeography it involves the use ofelectromagnetic radiation sensors torecord images of the Earth, which canbe used to yield useful information. Inthe 1960s remote sensing used blackand white aerial photography tointerpret patterns on the land. The launch of the LANDSAT 1 satelliteallowed remote sensing using non-photographic sources. Satellite imagery uses special camerasto pick up images based on theradiation given off by features on theEarth’s surface such as vegetation,soils and settlements. The patterns and relationshipsobserved are crucial in landmanagement and land use planning(see LANDSAT imagery, remotesensing, satellite image)

renewable natural resource — anatural resource that will not run outas a result of its use; it is considered tobe inexhaustible because it is inconstant supply. Geothermal energy,

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wind power, wave power, tidal powerand solar power are considered to berenewable natural resources

reserves — that part of a naturalresource base such as the variousminerals (eg gold, iron ore, uranium)that has not yet been, but can be,exploited using available technology.Some resources cannot be used usingavailable technology. However, whenthe technology has been developedthese inaccessible resources maybecome reserves to be used whenthere is sufficient demand. Forexample some oil deposits insedimentary basins around the worldcannot be extracted because thetechnology is not available. However, future drilling techniquesmay be developed and these can beincluded in the world’s stock of oilreserves

residual site — in the study of soilmaterials a residual site is a relatively flatarea such as a plateau surface where thedominant soil-forming processes occurin situ. Epimorphism is dominant; thatis weathering, leaching and newmineral formation. Typical soils includered earths and kraznozems (seedepositional site, transportational site)

resource depletion — the reduction inthe volume, or the deterioration in thequality, of a specific resource. Forexample resource depletion can beseen in the deteriorating volume of oilas a result of consumption – as well asthe deterioration in the quality ofwater for drinking and agriculture

retail warehouse park — an organiseddevelopment of at least three retailwarehouses totalling 50,000 ft2 (4600m2) of leased space

ria — a drowned river valley. Duringtimes of lower sea level on Earth (eg17,000 years ago) rivers cut V-shapedvalleys across the shallow continentalshelf. When sea level rose, these V-shaped valleys were flooded. InAustralia, the flooding of theParramatta River late formed what isnow Sydney Harbour, while theflooding of the Hawksbury River

formed Broken Bay. These areexamples of ria coastlines in NewSouth Wales

ribbon development — urban develop-ment following the narrow paths oftransport routes such as roads andrailway lines away from the urbancentre. A city for example may sprawloutwards with commercial activityfollowing the roads while residentialand industrial activity locates furtherbehind these areas

Richter scale — a measure of theintensity of an earthquake as recordedby a seismograph (see magnitude)

ridge — i) a long line of high land separ-ating two catchments or valleys; ii) ingeology, the landform created as aresult of magma rising to the Earth’ssurface forming a long area of elevatedland through which magma spreadseither side forming new crust. This is exactly what is happening alongthe Mid-Atlantic Ridge between Africaand South America and along the EastPacific Rise in the western PacificOcean. Evidence of the Mid-AtlanticRidge can be seen on the island ofIceland where the island is being splitinto two with active volcanoescommon on the island (see figure 7);iii) an area of relatively high atmos-pheric pressure where the isobarsextend outward from a centre of highpressure (see Trough). Air in ridges isrelatively stable due to subsidence

ridge and runnel topography —micro-topography that can form i) behind a beach berm whereby waterflows in the deeper runnels and isseparated by low ridges of sand; ii) along the sand flats exposed byreceding tides

riffle — a short, very shallow and fastflowing section of a stream. Riffles arecommonly found along the straightsections of shallow meanderingstreams (see figure 25, long profile,meander, pool)

rift valley — a steep-sided valleybounded by faults. In such areas theland may have sunk between thesefaults such as where rifting occurs. The

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Great Rift Valley in East Africa is anexample. It is being split as a result ofthe separation of two plates. TheValley extends over 1000 kilometresnorth-south and hundreds ofkilometres east-west (see continentaldrift, plate tectonics)

rill — a small channel, 1mm–20 cmwide, usually developed on steepslopes of unconsolidated materialsuch as volcanic ash and fine loose soilmaterial. Rills develop as water flowsacross the surface, forming smallchannels, and may eventually coalesceinto a larger deep, steep walled gully.

rill erosion — loss of surface materialsuch as topsoil by water erodingmaterial in rill channels

rime — also known as hoar frost, a thickcoating of white ice crystals onvegetation or other surfaces (see blackice)

Rio Declaration — following the June1992 Earth Summit in Rio De Janeiro,an agreement, in principle, wasdeveloped on expected environmentaloutcomes of nations formalised in adocument called Agenda 21

riparian land — land adjacent to a riveror other body of water. The term‘riparian rights’ refers to the rights ofpeople whose property backs onto ariver

Riversleigh — an area 250 kilometresnorth of Mt Isa in Queensland,Australia. It is one of the world’sric,hest fossil sites. It was declaredworld heritage site in 1994 because ofthe unique story it tells of Australia’srecent evolution as a continent.Archaeological evidence from this siteindicates that this area of Australia wasdominated by rainforest 15 millionyears ago (rather than the arid nature ofthe land now). Megafauna, such as thegiant marsupials, Procoptodon andDiprotodon roamed eastern Australiauntil about 50,000 years ago when theysuddenly became extinct. There ismuch debate as to whether a climatechange or hunting by Aborigines(known as Pleistocene Overkill) led totheir extinction

river terrace — also called anabandoned floodplain. A river will cutinto its bed and have a broadfloodplain either side of it. If the river cuts down further, due toan increase in discharge or a drop inbase level, the river will form a newfloodplain leaving the old one at ahigher elevation – abandoned. Ident-ifying river terraces gives an indicationof the history of river processes in thearea (see figure 25)

roche moutonée — an asymmetric rocktypical of glacial environments (or atleast providing evidence of formerglacial activity). The smooth gently sloping upslopeside shows evidence of glacialabrasion while the steeper downslopeside shows evidence of glacialplucking or the removal of discretepieces of rock as it becomes weakenedby the overlying moving ice

Rondônia — one of the States of Braziloccupying the southwest corner of theAmazonia region bordering Bolivia

Rossby Wave — vast meandering wavesof air in the upper level of thetroposphere. A band of strong westerly winds atlatitude 30°–40° North and latitude30°–40° South do not flow directlywest to east but wander north andsouth. In this way they play animportant role in distributing heatenergy across the globe (see jetstream)

Rowe, Brock — one of the drivingforces behind Geography in NewSouth Wale’s secondary schools duringthe latter half of the 1900s. A prolifictextbook writer Brock Rowe’senthusiasm in the field, and hispassion for the discipline, inspiredmany future geographers

runoff — water flowing downhill, eitheracross the surface as surface runoff, orbeneath the surface as subsurface orgroundwater runoff (see figure 32)

rural — referring to the countrysidesuch as farming or agricultural areas(see urban)

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negedic

rural urban drift — People move or driftto the city as a result of variouscentrifugal forces (push factors) inrural areas. These forces includefamine, drought, poverty and civil war .People are also attracted to cities bycentripetal forces (or pull factors).These forces include education,employment, medical services andentertainment. This rural urban drift is common indeveloping countries where peopleflood to the cities creating urban centressuch as primate cities. In developed countries rural urban driftwas very common in the 1950s–1980s.More recently the process ofcounterurbanisation has been

significant as many urban dwellers leavethe lifestyle of major metropolitancentres for a more rural lifestyle

rural-urban fringe — a transition zoneor area of gradual change between anurban area and a rural area. In therural-urban fringe there tends to be amixture of urban and rural functionssuch as housing estates and shoppingcomplexes as well as market gardensand small farms. The rural-urbanfringe attracts factories and otherbusinesses because of the relativelycheap land available in the area

rustbelt — a term used to refer to olderdecaying industrial areas of north andnortheast United States (seemanufacturing)

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Sahel — a strip of landthat extends for over5000 kilometres acrossNorth Africa. It extendsfrom Senegal and Maliin the west through

central Chad and southern Sudan tonorthern Ethiopia, Somalia andnorthern Kenya in the east. The Sahel forms the southern edge ofthe Sahara Desert and separates thearid Sahara Desert from the morehumid Central Africa. The Sahel region marks an area ofrapid change in climatic conditions.Rainfall amount changes quickly acrossthis area and the area is subject tofrequent drought and associatedfamine on a regular basis (see aridenvironment)

Sahul — the continental shelf offnorthwestern Australia. The Sahul wasexposed during the last glacial whensea level dropped creating more land.This occurred 20,000–15,000 yearsago. In some areas extensive seif dunesextended across this area suggestingthat the environment was much morearid than at present

salina — a saline (salty) spring or marsh;a saline drainage area; also a salt bed orsalt pan occurring in arid areas formedby evaporation leaving a salty crust(see playa)

salinity — the concentration of salt inthe soil. There are natural salts in allsoils eg sodium chloride; this is callednatural or primary salinity. However asa result of some activities of peopleadditional salts are added to the soil;this is called secondary salinity ofwhich there are two types (see drylandsalinity, irrigation salinity)

salvinia — a floating fern that can coverwaterways in weeks and doubling in

size in 2.5 days. It is an introducedspecies that is degrading much ofAustralia’s inland waterways (seedegradation)

Saami — indigenous people of Scandin-avia (see indigenous people, Lapp)

sacred site — a place of special (egspiritual) significance to Aboriginalpeople

San Andreas Fault — see transformfault

saprophyte — a plant that lives offdecaying matter such as fallen timberand leaves. Fungi are an example ofsaprophytes

Sargasso Sea — an area of the centralNorth Atlantic Ocean where the mix ofocean currents combines to bothelevate the sea surface about onemetre above the surrounding oceanand where material floating on thesurface tends to collect (see Ekmanspiral)

satellite image — this is an image orphotograph of an area taken fromspace by a variety of sensors recordingradiation given off by features on theEarth’s surface such as vegetation andcities. The information recorded fromthese sensors is then converted to animage from which decisions can bemade, for example long term land useplanning (see figures 62 and 66colour, remote sensing)

satellite suburb/community — asuburb or community, beyond therural-urban fringe, that is distantfrom, but functionally linked to, alarger urban community. Links includethe sale and purchase of goods andservices as well as a labour source andsource of employment

savanna, savannah — a grassland withsparse trees and shrubs. The BarklyTableland of western Queensland and

S


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eaastern Northern Territory is anAustralian example of grasslands. (seepampas, prairie, steppe veldt)

sawah — rice cultivation (farming) inIndonesia involving the use of terracesand an intricate irrigation system

scalding — the process where the landis stripped bare of topsoil exposingthe infertile subsoil. In this way theexposed B-horizon becomes barrenand unproductive. Scalding iscommon where tillage has exposedtopsoil to the erosive power of windespecially in agricultural areas

scale — on a map this is the ratiobetween the distance on the mapcompared to the actual distance onthe ground. This is shown as a linescale on the map, written in words (eg1 centimetre represents 1 kilometre),a representative fraction (1/100,000)or a ratio (1:100,000)

Scandinavia — a region in northernEurope consisting of the countriescalled Norway, Finland, Denmark andSweden

sclerophyll — a name given to plantswith hard leathery leaves. TheEucalypt species (eg gum trees) aresclerophyll-type vegetation. Sclero-phyllous vegetation is common in thetemperate mid-latitude areas such asEastern NSW, Australia. Rainforestvegetation is very different with softerand shiny leaves

schistosomiasis — a water-bornedisease also known as Bilharzia. Areasof poor water quality can act asbreeding grounds for microscopicworms. These worms breed inparticular snails in the water. Theworms enter the waterway andeventually attack the liver and spleenof infected people. Infected peoplecontinue the cycle as the worms enterwaterways as a result of urinating inthem. The disease that results,schistosomiasis, is a very debilitatingdisease with people being unable towork or sustain a livelihood. Manypeople become blind. It afflicts morethan 200 million people worldwide

especially in developing countries ofAfrica, South Asia, Southeast Asia andCentral and South America

scrape — A scrape is a common geo-morphic feature typical of karsttopography (or at least carbonate-richlithology). Scrapes are narrow verticalshafts extending down from the land’ssurface as a result of weathering viasolution — they may or may not beassociated with sinkholes (seedolines).

scree — loose rock debris across, or atthe foot of, a slope

sea — a body of salt water that ispartially enclosed by land eg theMediterranean Sea, the Tasman Sea.The Caspian Sea although totallyenclosed by land is in fact a lake.

sea breeze — a local breeze that blowsfrom the sea towards the landespecially in the late afternoon.During the day, the sun heats the landrelatively quickly compared to the sea.As a result, the air over the land heatsup forming an area of relatively lowpressure. Because the sea heats upmore slowly it remains cooler formingan area of relatively high pressure overit. As air of high pressure always movesto areas of low pressure a cool breezeblows from the sea onto the land; thisis common in summer (see highpressure cell, land breeze, lowpressure cell)

sea floor spreading — the mechanismby which new sea floor is created atridges such as the Mid-Atlantic ridgeand consumed or destroyed atsubduction zones. The plates either side of the ridgemove apart creating new crust andtherefore new sea floor. As the seafloor spreads from the ridges itplunges under less dense continentalland at subduction zones. Because of this continual cycling of thesea floor the youngest sea floor isadjacent to the ridges while the oldestsea floor is near subduction zones. Nowhere is sea floor older than 200–250million years old, although the

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continents are older than 3.5 billionyears. (see figure 17, plate tectonics,sial, sima)

seamount — an isolated ‘hill’ risingmore than 1000 metres above the seafloor (see guyot)

SEATO — South-East Asian TreatyOrganisation

secession — the political act of a smallterritory separating from and severingties with a larger state (or country) –eg Eritrea seceded from Ethiopia andEast Timor from Indonesia

secondary data — information that hasalready been processed or changed insome way eg information fromtelevision, textbooks and newspapers(see primary data)

secondary research — researchundertaken that works or manipulatesinformation already collected bysomeone else. Such research relies ondata already collected and collatedsuch as in newspapers or fromstatistical tables rather than researchthat relies on original fieldwork wherenew information is generated (seeprimary research)

secondary sector — that sector of theeconomy concerned with secondaryindustry (or manufacturing). Second-ary industries made up over 40% ofthe total workforce in Australia duringthe 1950s. With the decline in manufacturing dueto the growth in the service sector, theintroduction of new technologies, andincreasing competition from lowlabour cost overseas countries, onlyabout 20% of Australia’s labour force isemployed in the secondary sector

secondary succession — see plantsuccession

secondary treatment — followingprimary treatment of sewagebiodegradable organic matter isremoved by bacteria and other micro-organisms; this stage also tends toremove potentially harmful quantitiesof phosphorus and nitrate (seebiogeochemical cycle, phosphoruscycle, primary treatment, tertiarytreatment)

second world — a term not used widelytoday. In the past it referred to therelatively industrialised communistcountries such as the (former) USSRand the Easter European countries.Many of these countries are nowconsidered to be part of the developedworld (see First World and ThirdWorld)

sector theory (sector model) — atheory attempting to explain urbanland use patterns (Figure 58). Initially proposed by H. Hoyt, themodel suggests that land use patternswithin urban areas can be explainedby land use activity taking advantage ofroutes radiating for the centre of theurban area such as transport lines. The economic return received by theland use type will influence the routetaken and its distance from the urbancentre. In this way high income residentialland use will radiate from the urbancentre along the most desirableroutes, lower income areas along lessdesirable routes and with poorermanufacturing areas occupying poorerquality land between these (seeconcentric zone model, multiplenuclei model)

sedentary agriculture — typicallyapplied to forms of subsistenceagriculture that are practised in oneplace by a farmer or farmers over along period of time, for example ricecultivation (compare this with shiftingcultivation)

sediment — particles derived from theweathering and erosion of rock or thebreakdown of biological material. Inrivers sediment is transported bywater eventually to be deposited inareas where the energy of the river orthe volume of water is reduced (seedeposition)

sediment budget — identifies andattempts to quantify present-day gainsand losses of sediment to an area (orwhat is called a compartment). Thetopography of an area can beinfluenced by the gain, loss or balance

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of sediment in the area. Sedimentbudgets are used extensively oncoastal management programs such asbetween headlands and between thebeach and the surf zone. Themovement of sediment in a coastalsediment compartment can influenceareas of erosion and depositionleading to distinctive landforms suchas berms, spits and offshore bars

sediment load — the amount ofsediment being carried by a river

sediment yield — the total mass ofsediment transported in a catchmentarea. This is expressed for example astonnes per year or tonnes per squaremetre per year). The sediment in ariver may be carried in suspension assuspended load, or as bedload. Thesediment yield of a river reflects thetopography, geology, climate,vegetation cover, as well as people’sactivities within the river catchment.For example the sediment yield insparsely vegetated and steeply slopingareas can be very high due to highrates of natural erosion. They can beeven higher in areas where peoplehave cleared land especially in erosionprone areas. Sediment yield valuesfrom catchments have been recordedof over 15,000 tonnes per squarekilometre per year

sedimentary basin — a topographicaldepression often more than thousandsof square kilometres in area intowhich sediment has been or is beingdeposited. The Sydney Basin, NSW,Australia is a sedimentary basinextending from Port Stephens in thenorth, Lithgow to the west andBatemans Bay to the south. Thesediment that has accumulated overthe past 150 million years has nowturned to rock extending over twokilometres in depth

sedimentary rock — a rock formed fromthe sediment derived from theweathering and erosion of other rocks.Examples include sandstone and shale.Sediment has been deposited by water,wind, ice or gravity over millions ofyears, and has since turned to rock. The

Sydney Basin, NSW, Australia is anexample of an area where vastquantities of sediment have beendeposited. Vast quantities of finegrained sediment were initially laiddown by slow flowing meanderingstreams leading to what are now calledthe Narrabeen Shale deposits; overlyingthese are the coarser sands of theHawkesbury Sandstone reflecting afaster flowing riverine environment(see sedimentary basin)

seif dune — a long, linear sand dunethat is aligned in the direction of theprevailing wind. Seif dunes, also calledlongitudinal dunes, are common inthe Central Australian desert (seefigure 20)

seismograph — an instrument forrecording earthquake shocks

selva — a term used to describe thedense equatorial rainforest vegetation.The term was originally applied to therainforest vegetation of the AmazonBasin

sere — i) any stage in a plant successioneg a lithosere, a psammosere, axerosere; ii) a plant communityresulting from succession

service sector — that sector of theeconomy concerned with theprovision of services. The servicesector in economies of developedcountries makes up the great bulk ofthe workforce – such as those em-ployed in banking, insurance,education, and government

sesquioxides — iron and aluminiumoxides

settlement — i) a site occupied by agroup of people. A village, a town, acity are settlements; ii) a processwhereby people occupy an area

settlement pattern — the spatial arran-gement of a settlement. Settlementpatterns can vary greatly as a result offactors such as landforms, climate,history, social factors and economicforces. Settlements can follow river courses atthe bottom of valleys, irrigation canalsor even tops of mountain ridges. The

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pattern that can result from these canbe described as a linear pattern (orline pattern). In other instances such as in aridenvironments settlements may beseparated by vast distances; this showsa sparse distribution of settlement or adispersed settlement pattern. Where settlements group around aparticular feature such as an area ofrich soil or even where two rivers ormajor roads meet, settlement can bedescribed as dense or clustered. Settlement patterns can be looked aton a national or continental scale byidentifying the relationships betweenurban areas of different sizes (seeprimate city, rank size, binarysettlement patterns)

sextant — an instrument used widely innavigation to measure the angulardistance between two objects. Thelatitude and longitude of an observercan be found by determining theapparent altitude of celestial bodiessuch as stars

SEZ — see Special Economic Zone shanty town — an expression to

describe dwellings recently const-ructed on the periphery (outskirts) ofcities, especially in developingcountries. Shanty towns are not slums which areclose to the core of cities in developedcountries.Shanty towns have emerged in citiessuch as Calcutta (India), Rio de Janeiro(Brazil) and Mexico City (Mexico) as aresult of rapid rural urban drift due tofactors such as rural poverty, civil warand drought in many rural areas (seerural-urban fringe)

sharecroppers — farmers who renttheir land by giving a share of theircrop to the landowner

sheet erosion — a type of acceleratedsoil erosion where a thin film of waterdrains across land with very littlevegetation cover and removes a thinlayer (eg a millimetre depth) over awide area. This can lead to the loss ofa great quantity of soil (see erosion)

Proportion of Australians Living in Urban, Rural and Remote Settlements

TYPE OF SETTLEMENT Percentage (%)of total population

URBANbig towns and cities1 (over 1 million people) 59.7other cites (80,000 - 1 million people) 12.0

RURALlarge rural towns (25,000 - 80,000 people) 5.7small rural towns (10,000 - 25,000) 5.1Other2 (less than 10,000 people) 14.6

REMOTE3

Remote towns4 over 5000 people 1.2indigenous settlements5 0.4remote, other6 1.2

TOTAL (including offshore and migrant population) 100

1. mainly, but not only, State capital cities such as Melbourne2. people from farms and from small towns in agricultural areas3. areas used mainly for pastoralism, mining, tourism and indigenous purposes4. indigenous communities whose members are residents of large country towns

with a predominantly non-indigenous population5. indigenous townships, outstations etc where people are responsible for their own

municipal services6. mostly pastoral and mining settlements with 100�5000 people, with a large

Source: State of the Environment, Australia, 1995, AGPS, 1996, p.38

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Sherpa — name give to porters (orcarriers of equipment) in theHimalayas (such as in Nepal)

shield — an extensive area of acontinent where igneous andmetamorphic rocks are exposed at thesurface and are dominant surfacefeatures associated with a relativelylow lying topography of very old age.The Western Shield of WesternAustralia has rocks older than 600million years

shield volcano — a large volcanoshaped like a flattened dome and builtup by many flows of basaltic lava.Unlike composite volcanoes shieldvolcanoes cover a very wide area withslope angles of less than 10°

shifting cultivation — an agriculturalsystem characterised by field rotationin equatorial and tropical latitudes.Shifting cultivation involves:

• the initial clearing of land• the burning of the resulting waste

to provide nutrients for thenormally infertile forest soils

• the planting of a crop or crops inone field sometimes called a

swidden• cultivating this land 2–3 years. After

this time, the fertility of these soilsis diminished.

The shifting cultivators then move toanother area and the process beginsagain. In this way the initial integrity ofthe forest is compromised with forestreduced to a very different vegetationcommunity such as a woodland orgrassland – a completely differentecosystem results. Shifting cultivationis largely a subsistence form ofagriculture using relatively simpletechnology. Shifting cultivation is alsoknown as swidden agriculture andslash and burn agriculture

shoal — a submerged ridge, bank or barof sand on the bed of a stream, lake orthe sea. A shoal may be exposed at thesurface especially at low tide

shore platforms — cliffs along the coastare sometimes bordered by rockplatforms extending from their base tothe shore and sometimes beneath it(Figure 51 and 52 colour). It ispossible to recognise a variety of theserocky shore platforms:

Figure 51 � Types of shore platforms

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• high tide platforms – almosthorizontal rock platforms oftenwith a raised rim at the seawardedge. Following continual wettingand drying as a result of tidalmovements the small pools andchannels produced eventuallycoalesce wearing the platformdown to the layer of permanentsaturation. High tide platforms inSE Australia reflect present day sealevel

• low tide platforms – horizontal ornear horizontal platforms exposedbriefly at low tide. These are typicalof limestone rock type wheresolution is the major weatheringprocess

• intertidal platforms – gentlysloping platforms extending fromthe high tide mark of the recedingcliff to below the low tide mark.These platforms are common onrock types of uniform litholgy

sial — the continental crust consistingof a range of minerals but mainly ofsilica and aluminium

silcrete — a silica-rich material formedat or near the Earth’s surface. Wherethe products of weathering have led tosilica-rich minerals, or there has beenthe deposition of materials by silica-rich river systems over many millionsof years, an indurated crust mayeventually form. This crust may be between one andten metres thick. Today in CentralAustralia and southern Africa this crustacts as an effective shield againsterosion. Evidence of this silcrete canbe seen capping the tops of mesas andbuttes in arid environments (seeduricrust)

siliceous — relating to material such assoil being rich in silica; for examplesilica-rich (quartz) sand in soilsshowing little or no profiledevelopment

silicon landscape — an area dominatedby electrical and electronic equipmentindustry specialising in communicationequipment and other electronicservices.

These silicon landscapes have beenmore prevalent with the growth of thecomputer industry. Silicon landscapesinclude Northeast USA; Silicon Valley,California, USA; Silicon Glen incentral Scotland, and Silicon Beach inFlorida, USA

Silicon Valley — an area of manuf-acturing growth based on themicroelectronics industry south of SanFrancisco Bay in California, USA

sima — the oceanic crust and lower partof the continental crust consisting of arange of minerals but mainly silica andmagnesium

silt — very fine soil material typicallywashed away by rain and deposited bywater (see loess)

silviculture — the commercial growingof trees primarily for sale as comm-ercial timber

sinkhole — a hole, formed by solution,in the surface of limestone terrainoften with a stream flowing into it

site — the physical location of a place(eg on a hill, in a valley)

skeletal soil — a shallow, infertile soilcomposed of a large proportion ofpartly weathering bedrock (seeweathering)

slash and burn agriculture — seeshifting cultivation

sketch map — a map drawn free-handand not traced

slate — a fine-grained metamorphic rockformed as a result of the application ofheat and pressure on rocks such asmudstone and shale (seemetamorphism)

sleet — precipitation in the form ofwater and ice – especially a mix ofwater and snow

slipoff slope — a comparatively gentleslope of a spur inside the bend of ameandering stream, in contrast to thesteep bank on the concave, outsidebend of the stream (see meander)

slot valley — a valley, the cross sectionof which indicates that the rate ofstream incision, or vertical erosion, ismuch greater than valley widening.

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The deep, narrow valleys have nearvertical walls. Slot valleys can range insize from 100–200 cm deep whereerosion follows small natural joints inthe rock to valleys hundreds of metresdeep as can be seen in the BlueMountains, New South Wales,Australia

smallholder — a farmer who cultivatesa small agricultural area oftenconcentrating on one or two crops

smoker — a vent on the sea floorthrough which black, sulphur-rich gasconstantly seeps. These ‘smokers’ along the majorridges of the ocean floor indicate thepresence of underlying magma risingto the surface. At approximately 2–3 kilometresdepth, the temperatures and pressuresare enormous. Smokers are the

fumerole equivalent on the Earth’ssurface

snowline — the altitude above whichsnow lies throughout the year andbelow which snow melts in summer. The snowline varies with altitudethroughout the world, or even over amountain, as a result of factors such asaspect, wind strength and direction,and slope. These factors influence both thesummer maximum temperature andwinter minimum temperature. For example the snowline at one siteon a mountain may be 1800 metresbut on another site it might be 1750metres because of the different aspectof the slope

social cost — the cost or disadvantageincurred by a community. A social costwould include the loss of open space

Figure 53 � A soil profile

The verticalscale willvary fromsoil to soileg 30 cm �1 metre

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for community use as a result of a newhousing development

social environment — those featuresthat make up the human (or social)character of the area around us. The social environment includespopulation numbers and the distrib-ution of people, but more importantlyspecific characteristics of communitiessuch as ethnicity and interpersonaland social relationships (compare thiswith biophysical environment). The results of complex urban dyn-amics such as urban renewal andgentrification all contribute to thesocial environment

social justice — a concept relating tothe relative access to social benefitsand responsibilities. Social justice is concerned withensuring that all people have equalaccess to community resources suchas health services, housing, water andfood as well as community expec-tations such as employment. As such, social justice is a measure ofequality of outcomes. Where peopleare not permitted to vote when theyare legally able to, or when particulargroups in a community are deniedaccess to particular services, the levelof social justice is said to be poor

social capital — see social overheadcapital

social overhead capital — assets andresources that belong to thecommunity rather than the privatesector. Communities have developedthis social overhead capital such asschools, hospitals, public transportand cultural assets through theimposition of taxes. Social overheadcapital supports the ongoingfunctioning of communities such ascities (see infrastructure)

socioeconomic group — a classificationof a group based on occupation andincome. A high socioeconomic group issaid to have professional occupationsand high incomes. A low socioeconomicgroup is said to have relatively unskilledoccupations with low incomes

softwood — a type of wood producedfrom needle-leaved trees eg pine trees

SOI — see Southern Oscillation Indexsoil — a shallow zone of intermixed

mineral and organic matter exhibitingone or more horizons that differ fromthe underling regolith in morphology,particle size, composition etc

soil creep — the slow downslopemovement of soil particles under theinfluence of gravity. Soil creepcommonly occurs on grassedhillslopes where the stabilising effectof deep-rooted vegetation (trees) hasbeen removed

soil horizon — as it refers to soils, ahorizon is a definite and recognisablelayer within soil material or a soilprofile. A horizon such as a B-horizoncan be distinguished from otherhorizons in terms of colour, soiltexture and fabric or a combination ofthese (see figure 53)

soil profile — a vertical section throughthe soil from the surface to its parentmaterial, in many cases showingdistinctive soil horizons (Figure 53)

soil texture — the character of soil asdetermined by the relative proport-ions of sand, silt and clay. A soil can be described as being‘clayey’, or having a clay texture if ithas a large proportion of clay in it; a‘loam’ with an even proportion ofsand, silt and clay, a ‘loamy clay’, a‘sandy loam’ etc – or any combinationof the three main sediment types. An interesting field technique is toform a ‘ribbon’ – try to role amoistened clump of soil (called abolus) into a tube shape. If it forms atleast a 5cm long ‘ribbon’ it has clayeytexture; if it is very gritty and fails toform a ribbon the soil is said to have asandy texture

solar constant — the amount of solarradiation received on a unit area of theEarth’s outer atmosphere at theaverage Earth–Sun distance. The totalof this energy in all wavelengths iscalled the solar constant whichamounts to 1.94 calories per square

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metre per minute or 1.35 kilowatts persquare metre

solar eclipse — this occurs when theMoon passes between the Earth andthe Sun. The Moon obscures the lightfrom the Sun, received by the Earth.The Moon’s shadow is cast over theEarth. A total eclipse occurs when theSun is completely obscured (add lunareclipse)

solar flares — these develop in sunspotregions. They can be observed as theejection of mainly ionised hydrogen inthe Sun’s atmosphere at speeds inexcess of 1500 km/sec

solfatara — a phase of a volcano’s lifewhen gas and steam is released (seevolcano)

solifluction — the slow, downslopemovement of soil material as a resultof the soil being saturated with water.Solifluction is common in areas wherepermafrost is common. The soil is frozen in winter and uponthawing in summer the soil movesslowing downslope – especiallybecause of the lack of tree roots in thisclimate to bind the soil together. Solifluction rates can range between1–25 cm per year depending upon theangle of slope

solono — a hot, dry dusty wind of theMediterranean area

solstice — the time of year when theSun appears to be directly over theTropic of Capricorn or the Tropic ofCancer. In the Southern Hemispherethe Summer Solstice occurs when theSun appears to be directly over theTropic of Capricorn on the longest dayof the year, typically around 22–23December. The Winter Solstice in theSouthern Hemisphere occurs whenthe Sun is appears to be directly overthe Tropic of Cancer in the NorthernHemisphere; this is also known as theshortest day of the year – around 22–23 June. The opposite applieswhen speaking of the NorthernHemisphere

solum — the weathered soil abovebedrock; this is usually the combinedA-horizon and B-horizon

solution — a process, whereby particlesare dissolved and carried in a liquidsuch as water. For example saltdissolves in water and is carried insolution

South Asia — that part of Asiacomprising India, Sri Lanka,Bangladesh, Nepal, Bhutan andPakistan (see Southeast Asia, East Asia,North Asia, West Asia)

Southeast Asia — that part of Asiacomprising Burma, Thailand, Laos,Vietnam, Cambodia, Malaysia,Singapore, Indonesia, the Philippinesand East Timor

southerly buster — the name given tothe sudden change in weatherconditions when cold strong windsfollow the passage of a cold front. This is very common in southernAustralia when on a hot summer’s daywarm/hot northerly winds are replaced by cold winds from the south.This change occurs especially in theafternoon and is often accompaniedby short-lived heavy storms

Southern Ocean — an area occupyingthe vast region of the SouthernHemisphere, south of Australia,between approximately 40° to 60° Slatitude; 20% of all ocean area

Southern Oscillation — periodicchanges in atmospheric circulationover the Pacific Ocean. The ‘normal’situation of high pressure in theeastern Pacific (towards South Americawith dry conditions) and lowerpressure in the western Pacific andIndonesia (towards Australia with wetconditions), periodically reverses on a2–7 year cycle leading to cycles ofdrought and floods (see atmosphere,figure 23, general circulation,Southern Oscillation Index, Walkercirculation)

Southern Oscillation Index — anindication of air pressure differencesacross the Pacific Ocean; in particularlow pressure over Indonesia andnorthern Australia (read at Darwin)and high pressure over the central-western Pacific (read at Tahiti).

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A negative Index indicates higher thannormal air pressure over Darwinindicates possible drought overnorthern and eastern Australia (seefigure 23, high pressure cell, lowpressure cell, Southern Oscillation)

South Pacific Nuclear Free ZoneTreaty — this treaty, or the Treaty ofRarotonga, sponsored by theAustralian Government and signed bythirteen South Pacific Forum membercountries is designed to preventnuclear testing and the dumping ofwaste in the delimited nuclear freezone of the Pacific, and prohibit themanufacture, stockpiling, stationingand testing of nuclear weapons inAustralia. The treaty came into effect inDecember, 1986. However, France, anon-signatory, continues its nucleartesting program at Mururoa Atoll

spaceship Earth — a term used toemphasise that what happens on theEarth affects the whole planet — it isalone in space and should beconsidered as a single integratedentity

sparse — spread out, widely distributed;a sparse population is spread out overa large area (see dense)

spatial — a term to refer to an area orspace; eg spatial distribution – howthings are spread out over an area

spatial dimension — in studying ageographic issue consideration isgiven as to its specific location, why itis of concern there, where else theissue may be of concern, or how itaffects surrounding areas

spatial distribution — the distributionor spread of features such as citiesacross a geographic area. The spatial distribution of features canbe described as clustered or densewhere features are close together, ordispersed or sparse where features arespread far apart

spatial inequality — the geographicdivision/differences between individ-uals or groups. For example, spatialinequality can be seen in the locationof affluent groups and those subject to

poverty as well as the different orunequal access that these groups haveto health services, employment orwater

Special Economic Zone — the ChineseGovernment has set up SEZs allowingforeign firms to establish factories inthese particular areas of China (ie toallow small pockets of capitalism inChina). These SEZs have been set up to:

• introduce new technologies• develop links between China and

overseas• attract foreign investment• employ the many young people in

productive work speciation — the process by which new

species evolvespeleology — the study of cavesspeleothem — a depositional feature in

caves; such as a stalactite, astalagmite, a column, a flowstone anda curtain (Figure 54 colour). Water infiltrating through the roof ofthe cave is slightly acid from thedecaying vegetation above. The largelycalcium carbonate deposits aredeposited in an array of differentforms within the cave

spinifex — a tough grass growing insmall tufts in arid areas

spit — a coastal feature where alongshore current has deposited sandforming a long depositional feature,which is linked to the land, typicallyexposed at the surface, and is abovethe highwater mark. A sand spit can extend across themouth of a bay (extending thecoastline) and in many cases closingoff the bay to the open ocean forminga lagoon behind it (see longshoredrift)

SPOT — a French satellite, ‘SatelliteProbatoire pour l’Observation de laTerre’, that provides images of theEarth’s surface. Launched in 1986 it has a resolution of10 metres (see LANDSAT)

spot height — the height in metresmarked on a topographic map that has

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been measured or computed from adatum or base level such as a sea level

spray irrigation — the irrigation ofcrops where water is sprayed fromabove the crop. This is very differentfrom drip irrigation

spring equinox — an event that is theresult of the Earth’s revolution aroundthe Sun. In the Southern Hemispherethis event occurs 22–23 September. At this time, the Sun appears to bedirectly over the equator. This is alsoknown as the vernal equinox in theSouthern Hemisphere

spur — a ridge of high land slopingdown to the main river channel in acatchment area usually at right anglesto the river (see truncated spur)

stack — a sea stack is part of a cliff thathas separated from the mainland as aresult of the erosive effect of waves.This is often seen as a lone outcrop ofrock lying off the coast. An Australianexample can be seen at The TwelveApostles off the Victorian coast (seeerosion)

stalactite — an example of aspeleothem. As acidic water seepsthrough limestone rock it dissolvesvarious minerals. These minerals suchas calcite can be seen precipitating onthe ceiling of a cave and hanging fromthe roof

stalagmite — an example of aspeleothem. Forming in a similar wayas a stalactite, a stalagmite forms onthe cave floor as calcium carbonate insolution drips from the ceiling buildupwards from the cave floor

standard time — the average (or mean)time along a meridian of longitudelocated at the centre of a zone orcountry. The Earth is divided into 24 meridians of 15º. Each of theseinternational time zones formstandard time within these zones. In countries such as Russia, Australiaand USA there are several standardtime zones

steppe — a grassland found in the mid-latitude areas of Eastern Europe andRussia (see savanna)

Stockholm Conference — a UnitedNations conference on the humanenvironment, held in Stockholm, 1972

stratosphere — the region of theatmosphere approximately 15–50 kilo-metres above the Earth’s surface.Unlike the troposphere temperatureschange every little or increase slightlywith height (see figure 2)

strip mining — see open cut miningStromatolites — organic structures

built up especially in marine andlacustrine environments. More than 2.5 billion years ago micro-organisms trapped sediment andsuccessively built up organic/sedimentary layers forming theseprimitive colonies. The best knownexamples of stromatolites are on thewestern coast of Australia providingevidence of early life in Earth history(see figure 27)

subaerial — occurring or acting on theEarth’s surface eg subaerial weath-ering occurs on the surface of theland, opposed to the marine weathing

subduction zone — a zone where onelithospheric plate dips beneathanother forming an ocean trench. As one plate moves towards anotherthe ocean floor plunges underneaththe continental crust because theformer is more dense (or ‘heavier’).The ocean floor slides under the landat a very steep angle. This subductionzone can extend as deep as 700–1000km. These are the sites of majorearthquakes and at these depths rocksbecome molten and eventually rise tothe surface to be seen as volcanoes.Subduction zones are what are calledconvergent plate boundaries becausethese are the sites where platescollide. Evidence of these can be seenaround the Pacific Ring of Fire (seefigure 17)

sublimation — the change of asubstance from one state to anotherbut bypassing an intermediate state.For example the change of state of ice(solid state) directly to a gas withoutthe intermediate liquid phase.

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Sublimation is common in very highlatitudes such as in northernScandinavia and northern Canada

sublittoral zone – below low tide level(see littoral zone, supralittoral zone,tides)

subsidence inversion — an inversionin the upper troposphere. In the loweratmosphere when air rises it coolsadiabatically due to the air expandingin an area of lower pressure. The air temperature near onekilometre, for example, might be 2°C.However air tends to sink (or subside)in subtropical high pressure systemssuch as over central Australia. As theair sinks from high altitudes (eg fromover 5 kilometres altitude) it warms upas a result of compression. The temperature of this subsiding airat, for example, one kilometre mightbe 3°C. The lower air near onekilometre is cooler (2°C) than the airjust above it (3°C). The lower coolerair cannot rise any further. There generally is no cloud in thesubsiding air. The implication of this isthat air in the lower atmosphere findsit difficult to rise to such altitudes toproduce rainfall. A subsidence inversion like this iscommon over arid areas in thesubtropics (20°–30° latitide north andsouth of the equator) (see adiabaticlapse rate, subtropical high pressurecell)

subsidiary — a branch of a largercorporation which tends to specialisein a particular aspect of the largercorporation or operates in a differentmarket — either domestic or overseas

subsistence — a term used to describethe objective of a type of agriculturewhere food is produced for personal(or domestic) consumption ratherthan commercial production wherefood is produced for sale

subsistence agriculture — an agricul-tural system in which little or nosurplus is produced. The crops grownor cattle raised are primarily for the

individual’s consumption and not forsale.

subsistence economy — an economicsystem whereby people produce thebulk of their own food forconsumption. Production and cons-umption are restricted mainly to thefamily unit with very little exchangebetween groups. Although traditionalrice cultivation and shiftingcultivation have been described asexamples of subsistence agriculture,there are virtually no subsistenceeconomies in world today as a resultof the social, political and economiccontacts between all areas of the Earth

subtropical high pressure cell — afeature of relatively high air pressurewithin the global atmosphericcirculation. These areas of highpressure are located between thetropical latitudes of 20°–30° north andsouth of the equator. Between theselatitudes air is descending through thetroposphere forming an area of highpressure. This leads to dry surfaceconditions as can be seen in areas suchas central Australia and the SaharaDesert in North Africa. The mainreason for this is that as the air sinks itwarms adiabatically at 10°C per kilo-metre (see adiabatic lapse rate, generalcirculation, figure 26, subsidenceinversion)

suburbanisation — a process wherebywork, services, population andhousing estates are located indispersed areas beyond, and indep-endent of, the city core

succession — see plant successionsucculent — a type of plant with

juicy/fleshy leaves (eg cactus)Sudd (the) — an area of southern

Sudan (Africa) through which theWhite Nile flows. The area isdominated by low-lying swamps andbeing subject to inundation duringheavy rains

summer solstice — an event that is theresult of the Earth’s revolution aroundthe Sun. In the Southern Hemispherethis event occurs 21–22 December.

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Figure 55 � An example of a synoptic chart

At this time the Sun appears to bedirectly overhead at 23½°S (Tropic ofCapricorn); this is known as thelongest day of the year in the SouthernHemisphere. In the area south of theAntarctic Circle (66½°S) light isreceived 24 hours of the day

sunbelt — a term used to describe theprosperous and growing areas of thesouth and west of the United States

Sunda Land — that part of thecontinental shelf between Australiaand Southeast Asia including Java,Sumatra and Kalimantan. It was theSunda which early Aboriginal peoplecrossed from Asia into Australiaapproximately 100,000 years ago.They did not only walk across whensea level was lower but used watercraft at times to ‘island hop’ the muchshorter distances that were available tothem (at 105,000, 55,000 and 17,000years ago)

sunrise industry — new and existingindustry taking advantage of newtechnology such as computertechnology and new methods of

production – especially used whenreferring to new service industries

sunset industry — old and decliningindustry often producing old and outdated products using out of datetechnology and methods of prod-uction – especially used whenreferring to manufacturing industry

sunspots — regions on the Sun’ssurface of intense magneticdisturbance (100–1000 times theaverage for the Sun). They appear darkbecause convection on the Sun’ssurface is reduced leading to coolingby the emission of radiation seen assolar flares

supralittoral zone — above high tidelevel (see littoral zone, sublittoralzone, tides)

sustainable development — a conceptthat suggests that economic develop-ment can proceed indefinitely as longas the rate of use of natural resourcesdoes not exceed the rate of replace-ment of that resource nor does itadversely affect the quality of otheraspects of the natural or humanenvironments

SCALE: 1 CM = 900 KM

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sustainable yield — an objective ofresource use in which the rate of usedoes not exceed the rate ofreplenishment or renewal. For example, in the fishing industry asustainable yield is one in which fishcatches do not exhaust the stockavailable — ie fish stocks arecontinually replaced allowing for thelong-term use of this resource. The same applies to resources such asforests, and fossil fuels (seesustainable development)

swale — a depression between two sanddunes. In coastal environments theswale between two frontal (orparallel) dunes is often thicklyvegetated, for example by taller trees,due to the more protected and moistmicroclimate

swallow-hole — where a surface streamdisappears underground especially inlimestone terrain (see doline, karst,sinkhole)

S-wave — a seismic wave within theEarth (generated by an earthquake)due to movement in the Earth’s crustand upper mantle. Secondary wavesdo not pass through the Earth’smolten core. As a result they are notreceived on the opposite side of theglobe. There is a ‘shadow’ or area wherethese waves are not recorded (see P-waves)

swash — as a wave breaks along thecoast the water rushes up the beachface; this water is known as the swash(see backwash, longshore drift)

swell — the movement of waterconsisting of wind generated wavesthat were formed in another area. The long wavelength of these waves isreduced as these waves approach thecoastline. Swell can be seen as those wavesmoving onshore from far out to sea(see figure 14)

swidden — see shifting cultivationswidden agriculture — see shifting

cultivationsyncline — the trough in a fold formed

as result of Earth movement (see foldmountains)

synergism — the process by which thecombined effects of two or moresubstances are greater than the sum ofthe individual effects

synoptic chart — also known as aweather map which gives a summaryof weather being experienced in anarea (eg over Australia) by the use ofisobars. We can then determine winddirections and estimate temperaturesetc (see figure 55)

syzygy — one of two points where theEarth and the Sun are aligned with theMoon or another planet

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taiga — an area of con-iferous forest near theArctic Circle. The coldwinters in areas such asthe countries of Scand-inavia (Russia and

Canada allow only a short growingseason with trees such as spruce andpine adapted to this condition

tailings dam— a dam that collects thewaste material from mining sites andprocessing sites where the materialcollected is deemed too poor to beprocessed further. For exampletailings dams are used to collect wastefrom gold and uranium mines

Talgai — the name given to the firstAustralian Pleistocene human skull –found in southern QueenslandAustralia in 1886 with a minimum ageof 14,000–16,000 years (see KowSwamp, Lake Mungo)

talus slope — a slope at the foot of acliff made up of weathered rock debris(see scree, weathering)

taluvium — as a jointed rock massbreaks down on a hillslope themixture of this talus from thebreakdown of joint blocks, andcolluvium is collectively known astaluvium (see weathering)

tariff — a tax on goods entering acountry making the product moreexpensive

tarn — a glacial lake. A cirque hasscoured into the side of a mountainby the action of ice. Upon melting, thedepression has filled with waterforming a lake or tarn (see figure 28)

TCM — see total catchmentmanagement

technoburb — a node that is function-ally separated from the city proper,made possible by technologicallyadvanced industries

tectonic — a term that relates toprocesses that operate within theEarth. The various types of mountainbuilding and folding and faulting aretectonic processes (see fault, fold, foldmountains, volcano)

teleworking — or telecommunicating,where electronic communicationenables people to work from homerather than physically travel to aworkplace

temperate — a name given to describethose areas and climates of the Earththat are not subjected to continualextremes of temperature and precip-itation. Temperate areas (or latitudes)include Australia’s southeastern coastof NSW, the east and west coast of theUSA and South Africa. Temperate areascontrast with tropical and equatorialclimates, the arid climates of manywest coast and central areas ofcontinents, as well as the subpolar andpolar climates of higher latitudes

temperature range — the differencebetween the highest and lowesttemperatures (eg 30°C–20°C has atemperature range of 10°C)

tenement — a large multistorey citybuilding that is divided into rooms orapartments for rent. Tenemantsprovide high density, often poor-quality, accommodation

tenure — land ownership (see freeholdtenure, land tenure, leasehold land)

tephra — material ejected from avolcano during an eruption includingash, dust and large rocks or boulderscalled volcanic bombs (see volcanicrock)

tephrochronology — a dating tech-nique using tephra from a volcaniceruption. The date of the tephra isdetermined so that material above andbelow the tephra can be correlated to

T


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give relative age. Material below thetephra is older than the date of thetephra and in turn younger than alower tephra layer. Compare withdendochronology (see volcano)

Terania Creek — the site of the firstanti-logging demonstration inAustralia (1979) — 30 km north ofLismore, NSW Australia

terminal moraine — glacial sedimentaccumulated at the toe or lower partof the glacier

ternary graph — a triangular diagrammeasuring three related variablesrather than the more familiar two; forexample, comparing the relativeproportion of people working in theprimary, secondary or service sectorsof the economy. Each side to thegraph, an isosceles triangle, has ascale. The scale is read by reading thenumbers on the scale 0–100 from thelower right corner at 60° to the axisthat is being read

Terra Australis Incognita — Latinmeaning ‘unknown southern land’;used when referring to Australiaespecially in the seventeenth centuryduring early exploration

terrace — see river terraceterrestrial — a term relating to the

Earth, or of living on the land. Forexample, terrestrial vegetation isvegetation growing on the land ratherthan in the ocean (see aquatic)

territorial waters — waters under thejurisdiction of a country including seasand inland water bodies

Tertiary Period — a period ofgeological time 66.4–2.8 million yearsago. Part of the Cenozoic Era (seefigure 27)

tertiary sector — that sector of theeconomy concerned with the prov-ision of services. In most developed countries, thetertiary sector makes up over 75% ofall types of employment. Those peopleemployed in the tourist, insurance,and computer service industriesbelong to the tertiary sector (seeprimary sector, quaternary sector,

quinary sector, secondary sector,service sector)

tertiary treatment — the removal of arange of substances such as nitrates,phosphates, chlorinated compounds,toxic organic materials, heavy metals,acids, and salts. Bacteria and evensmaller viruses can be removed withmicrofiltration technology (seeprimary treatment, secondarytreatment)

Tethys Sea — the body of water thatseparated the northern landmass ofLaurasia from the southern landmassof Gondwana

texture — see soil texturetexture contrast soil — a soil with a

marked contrast (or difference)between the upper A-horizon and thelower B-horizon. In situ processes,such as weathering, acting on thebedrock, produce a relatively finetextured clayey B-horizon. Surface processes, such as slope washand soil creep acting across the slopeand over the B-horizon, produce amuch more coarse sandy-loam A-horizon. Some examples of texturecontrast soils are the red and yellowpodsols. These soils are commonlyfound on hill slopes (see duplex soils)

thalweg — a theoretical line along thecourse of a river joining the deepestparts of its bed (see graded profile,long profile)

thematic map — a type of map thatshows a particular topic or theme suchas how temperature, population orincomes vary over an area

The North — a term used to describethe more developed countries of theworld. The North includes Canada,USA, Australia, New Zealand, Japanand countries of Europe (see Brandtline)

the Sudd — see Sudd (the)thermocline — the surface layers of the

oceans are a mixture of warmtemperatures, mixing waves andvariable currents. Below this, about100m below the surface, the

aryewhy

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temperature falls very rapidly forabout 1000 metres. This is called thethermocline. Below the thermocline,1–3 kilometres deep, temperatures arejust above freezing point andtemperatures decrease very slowlywith depth

thermal expansion — a type ofphysical weathering whereby the heatreceived by a body, such as a rock,leads to the expansion of the outerlayers of that rock. This in turn canlead to the outer layers of the rockpeeling off (see exfoliation)

thermosphere — a region in theatmosphere, greater than 80 kmaltitude, where temperature increasesrapidly with height. The temperaturecan reach over 1000ºC due to theincreasing absorption by atomic oxygenand ozone of incoming shortwaveradiation from the Sun (see figure 2)

The South — a term used to refer todeveloping countries of the world.The South includes countries such asIndia, Libya, Thailand, Costa Rica,Brazil and Argentina (see Brandt line,The North)

third world — a term not used widelytoday. In the past it referred to thepoorer countries experiencing greatpoverty in Asia, Africa and Central andSouth America. These are nowreferred to as developing countries,The South or the majority world (seefirst world and second world)

three mine policy — a policy called theThree Mine Producers Policy of theHawke Labor Australian Government(1983) approved Nabarlek and Rangermines (Northern Territory) andOlympic Dam (South Australia).Nabarlek is no longer operating; it wasdecommissioned in 1995. OlympicDam produces 2 billion tonnes of oreconsisting of 30 million tonnes ofcopper and over 100 million tonnes ofuranium. It is an underground mineunlike the open cut mine of Ranger.Ranger Uranium Mine, 260 km east ofDarwin, is owned by ERA (EnergyResources Australia), covers an area of

79 square kilometres and is surr-ounded by Kakadu National Park

threshold population — the minimumpopulation number required tosupport the provision of a good orservice by a central place (see centralplace theory)

throughflow — the downslope flow ofsubsurface water through the voids (orspaces) in the regolith towards a chan-nel or the water table (see figure 32)

Thylacoleo carnifex — part of theextinct megafauna that roamedeastern Australia prior to 15,000 yearsago; a ‘marsupial lion’ thought to be acarnivore

tidal bore — the ‘pulse’ of water some-times seen as water moves upstream asa result of the incoming tides

tidal power — power or energyproduced as a result of the rise and fallof the tides. A barrage across an armof the sea, as in an estuary, rises andfall with the tide. As the tide rises andfalls it turns hydraulic turbines aswater passes through them. This is anexample of renewable energy withlittle impact on the environment.However costs are prohibitive (seerenewable natural resource)

tides — these are the regular movementin ocean levels as a result of thegravitational attraction between theEarth, the Moon, and to a lesserextent, the Sun. The gravitational force exerted by theMoon on the oceans facing the Mooncauses the oceans to bulge out slightly— this causes high tides. In some areastides can rise over 10 metres. When the Earth, Moon and Sun are inalignment they cause a maximum riseand fall of the oceans that calledspring tides. When the three bodies are at rightangles to each other the forces areminimal and very small tides resultcalled neap tides. The effects of tidescan be seen upstream in rivers as atidal bore moves up river and a smallwave can sometimes be seen movingupstream. Contrast with a tsunami

tied aid — see foreign aid

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Tierra del Fuego — the southern regionof Argentina and the South Americancontinent. It is actually an islandseparated from the mainland by theStrait of Magellan. The western half ofthe island is part of Chile

till — a mixture of rocks and claytypically deposited over the landscapeby glaciers such as over central andnorthern North America and Europeduring the last glacial period. Tilldeposits indicate the previouspresence of glaciers and evidence ofclimate change in the area in which tillis found (see deposition)

tillage — the preparation of topsoil forcrops or for weed control bymachinery

TNC — see transnational corporationtombolo — a spit that links an offshore

island to the mainland as a result oflongshore drift. In the example of Palm Beach (Figure56) recent research suggests that thismay not be a tombolo at all. Underlying bedrock suggests that anow submerged ridge extended toBarrenjoey making Palm Beach abayhead beach

Figure 56

The tombolo of Palm Beach, NSW,Australia, linking the �island� of Barrenjoey

to the mainlandtopographic map — a large-scale map

of part of the Earth’s surfaceillustrating various features of the

biophysical environment, such ashills, valleys and vegetation, and thebuilt environment that includesbuildings and roads (see figures 64and 68 colour)

topography — the shape and physicalfeatures of the Earth’s surfaceincluding hills, valleys, mountainousand gently-sloping topography

topology (and topological map) — thisis concerned with the order and relativeposition of the feature rather than theiractual positions or dimensions. Arailway map is a typical example of atopological map in that it shows whererailway stations are in their correctorder but not necessarily the actualdistances between these stations

tornado — an intense area of lowpressure originating over land. Theviolent storm can be seen around along funnel cloud impacting on arelatively narrow area compared to thebroad areas of devastation associatedwith tropical cyclones. Tornadoes arethought to originate when a layer ofdense cold air moves over a layer of warm, moist unstable air. Becauseof this difference, energy is released. The sudden displacement of air causesan intense area of low pressuresucking air in from the sides thenrising rapidly. The spin of the Earthcauses the air to spiral upwards (seelow pressure cell)

total catchment management — theintegrated management of all land usetypes within a catchment area.Landowners, residents, governmentdepartments and private organisationshave an interest in their catchment.These groups and individuals makeland use decisions with the objectiveof having little or no negative impacton the quality of resources within thatcatchment. In this way, the wholecatchment is protected from variousforms of land degradation and thelong-term sustainable development ofthe catchment’s natural resources isassured

tourism — the temporary and freemovement of people to destinations

SCALE: 1 CM = 500 M

N

!

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outside their normal residence and workplace in order toexperience contrasting lifestylesand/or environments

trade liberalisation — a trading policybased on free market conditions withlittle or no government influence suchas tariffs

trade waste — waste from industrialprocessing. Trade waste includesliquids such as oils and fats, solids suchas paper and metals and gases emittedfrom chimneystacks. Trade waste isparticularly an environmental problemin densely populated areas andespecially in rivers. Many riversbecome aquatic deserts as life formsdie through lack of oxygen. This occursbecause oxygen is used up to breakdown the many forms of trade waste

trade winds — easterly winds that blowfrom the subtropical latitudes (such aslatitude 20°S–30°S) towards theequator. In the Southern Hemispherethey are called the SoutheastTradewinds because the coriolis forcedeflects these winds to the left. In theNorthern Hemisphere winds blowingfrom the subtropics to the equator arecalled the Northeast Tradewinds (seefigure 26, general circulation)

tragedy of the commons — where apublicly owned, freely available,unregulated resource is likely to beoverexploited. First used in relation tothe progressive degradation of ‘thecommons’ in England. The tragedy ofthe commons idea is used to argue forgovernment control, good man-agement of modern ‘commons’, andthe promotion of ecologicalsustainability so that those whoaccrue profits meet all environmentalneeds (see sustainable development)

transect — a cross section of part of theEarth’s surface. A transect diagramgives a summary of features along thistransect including settlement andlandforms (see topographic map)

transfer pricing — a term used todescribe price-setting for differentproducts within the one company

transform fault — a fault in the Earth’scrust the result of two crustal platessliding past one another, rather thanone plate being subducted beneathanother, or the two plates collidingand then forming features such as foldmountains). The San Andreas Fault (USA) is anexample of a transform fault as theNorth American Plate slides passed thePacific Plate (see figure 44, subductionzone)

transgression — a rise in sea level on aglobal scale . The coldest phase of the last glacialperiod, 20,000–17,000 year ago, sawsea levels at 150–200 metres belowpresent with water locked up inglaciers as well as the Greenland andAntarctic ice caps. As climates warmed the glaciers andice caps began to melt. Sea level roseto reach its present level byapproximately 6000 years ago. This transgression of the ocean sawthe flooding of fiords and rias (seeclimate change, regression)

transgressive dune — a dune commonin coastal dune systems, formed as aresult of onshore winds blowing largevolumes of sand inland. These dunesindicate that the main foredune hasbeen destabilised in some way such asvegetation being removed by walkingtracks. They are also known asblowouts

transhumance — the seasonalmovement of people or cattle up ordown mountain sides or on the desertfringe in search of better pastures. Anexample of this is the downslopemovement in winter to warmertemperatures and a more plentifulfood source

transmigration — a resettlementprogram undertaken by theIndonesian Government that has seenmovement of people from the denselypopulated island of Java to lessdensely populated areas such as,Kalimantan and Irian Jaya and theislands of Sulawesi and Lombok

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transnational corporation — a largecompany that operates in more thanone country. In many instances TNCscontrol various aspects of theproduction process. Examples includeGeneral Motors, Exxon, GeneralElectric, Samsung, Unilever andBritish Petroleum

transportational site — in the study ofsoil materials transportational sites areareas such as hillslopes, where soilmaterials are the result of two mainprocesses. The upper A-horizon is the result ofsurface processes such as slope washand soil creep leading to a relativelysandy texture with little or no pedaldevelopment. The lower B-horizon has a much moreclayey texture, the result of in situprocess such as weathering leachingand new mineral formation. Texture contrast soils are typicallyfound at transportational sites (seedepositional site, duplex soils,podsols, residual site)

travertine — a form of limestone thatforms features such as stalactites andstalagmites created by the drips ofcalcium-rich springs

Treaty of Rarotonga — see SouthPacific Nuclear Free Zone Treaty

tree — a woody plant usually with onestem and more than 5 metres tall

tree line — the altitude, above which,trees do not grow. Althoughtemperature is a major factor, theposition of the tree line is influencedby a range of other factors such asaspect, slope, soils and drainage. The position of the tree line on oneside of a mountain may be 1750 mwhereas it might be 1810 m onanother side because of differences intemperature, moisture and soil type(see snowline)

tree preservation order — a powerexercised by a local planning authorityNSW such as the local council, thatprohibits the lopping, clearing ordeliberate destruction of local trees orgroups of trees

trend line — a line drawn on ascattergraph to emphasise the mainpattern (or trend) in the data shown.Two types of lines are a line of best fitand a regression line

tributary — a small stream that joinsanother to form a larger river (seefigure 25)

trophic level — a level in a food chain.A trophic level can be represented by apyramid where the base is tropic level1: producers, level 2: herbivores, level3: carnivores, and level 4: omnivores(see pyramid of biomass, pyramid ofenergy, pyramid of numbers)

trophic structure — feeding relation-ships within and between ecosystems

tropical cyclone — an area of intenselow pressure common in northernAustralia and Indonesia bringingstrong winds and torrential rainfall(see hurricane, low pressure cell,typhoon)

Tropic of Cancer — an imaginary linearound the Earth in the NorthernHemisphere (23½°N)

Tropic of Capricorn — an imaginaryline around the Earth in the SouthernHemisphere (23½°S)

tropopause — the boundary betweenthe troposphere and the overlyingstratosphere. The altitude of thetropopause varies from about 15 km at the equator to about 6–7 kmat the poles (due to greater convectionat the equator ). Within the tropopause, temperaturestend to increase with height or remainconstant, unlike the troposphere.Because of this physical characteristicthere is little transfer of air across thislayer. The tropopause acts as a lid, orinversion, above the troposphere. Rising convection currents such aswithin thunderstorms cannot easilybreak through the tropopause. As a result the area is characterised byrelatively clear skies free of cloud (seefigure 2, adiabatic lapse rate,troposphere)

troposphere — the area of the Earth’satmosphere in which our weather

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occurs (coming from the Greekmeaning ‘turning’). Within the troposphere insolationenters the Earth’s atmosphere and isabsorbed by the land and the oceans.This short wave radiation is convertedto long wave radiation (or heat). This heat energy then heats theatmosphere by processes such asconduction and convection. Convection is much stronger in the low equatorial latitudes so thetroposphere is much deeper here(approximately 12 kilometres) whereasthe depth decreases towards the poles(approximately 5–8 kilometres)because the air is more dense. Withinthe troposphere, temperature tends todecrease with height at about 6.5°C perkilometre. This ‘normal, or environ-mental lapse rate can vary greatly (seefigure 2)

trough — an area of relatively low airpressure where the isobars extendoutward from a centre of lowpressure. Air in troughs is relativelyunstable with air rising from thesurface and diverging at higheraltitudes. Troughs are often associatedwith fronts and can lead to cooler andsometimes stormy weather (see ridge)

truck farming — the production offresh vegetables at a great distancefrom the market to which they are tobe sold. Fast and refrigerated transporthas allowed this type of farming on theperiphery of metropolitan areas (seecommercial farming)

Truganini — the last survivingAboriginal (female) in Tasmania(Oyster Cove, south of Hobart).Truganini died in 1876 aged 71. Thelast surviving male was William Lanney(King Billy) who died in 1869 aged 34

truncated spur — the lower end of aspur that has been ‘cut off ’ (ortruncated) by erosive action. This maybe caused by a glacier (see figure 28,erosion)

tsunami — a sea wave, with a large waveheight up to 15 metres, often resultingfrom an undersea earthquake.Tsunamis are often mistakenly called‘tidal waves’; they have nothing to dowith the diurnal tides

tuff — fine-grained material, such as ash,ejected from a volcano commonlyfound as a sedimentary deposit at thebase of the volcano. Evidence of tuff isused to indicate that volcanic activityoccurred in a particular area, and as asource of dating archaeological events(see climate change, sedimentary rock,tephro-chronology)

tundra — vast, relatively flat treeless andoften, marshy plains characterised bythe presence of permafrost. Tundrahas normally been associated with thevast northern areas of Canada andwhat is now Russia. Plants such asmosses, grasses and low heath plantsare common and adapted to the coldtemperatures and seasonally frozenand wet land surface. The term tundrais used more widely to also includethose lands above the tree line inalpine environments

turbidity — a measure of the‘murkiness’ of water. Turbidity iscaused by suspended solids in thewater such as soil material havingbeen washed into a river followingheavy rainfall. Water with a highturbidity is detrimental to muchaquatic life because the suspendedmaterial tends to block sunlight frompenetrating to any great depth and solimiting the process of photosynthesis

Twelve Apostles — located off thesouthwest coast of Victoria, Australiathese sandstone rock stacks (see stack)form part of the rugged coastlineweathered and eroded over millions ofyears (see erosion, weathering)

typhoon — an area of intense lowpressure common in Asia bringingstrong winds and torrential rainfall(see hurricane, low pressure cell,tropical cyclone)

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ubac — the side of a hillmost sheltered from thesun

UN — (see United Nations)underclass — the poorforced to the margins or

out of the labour market in a post-industrial society, thus excluded fromthe mainstream life of society

underemployed — a phenomenonwhereby people are in employmentbut do not have sufficient work tooccupy them

underfit stream — see misfit streamUNDP — United Nations Development

Program. Created in 1965 the UNDPhas four priority areas:

• the elimination of poverty• creation of jobs and sustainable

livelihoods• advancement of women• the protection and regeneration of

the environment. Much of the work of the UNDP isdirected to restoring societies afterwar and humanitarian emergencies.The majority of funds is directed todeveloping countries with over 80%aimed at countries with GDP percapita of less than $750

undulating — refers to gently rollingland (or topography) rather than flator even steep land

UNEP — United Nations EnvironmentProgram. This was established in 1972.The UNEP has the task of developingand promoting sound environmentalactivities around the world. With the increasing consumption ofnatural resources around the world,such as forests, fossil fuels and marinestocks, the UNEP is focusing onsustainable development practices toenhance environmental quality andthe quality of life of people

UNESCO — United Nations Educational,Scientific and Cultural Organisation

uniform texture — in describing soiltexture, a uniform texture has a similartexture grade throughout the solum(see duplex soil, gradational texture)

uniformitarianism — a concept thatdirected much thinking in the 19thand early to mid 20th centuries. It suggested that the processes that acton the Earth today are of the sametype, and operates at the same rate, asthose of thousands and millions ofyears ago. This idea of uniform processes andrates, suggested by the phrase ‘thepresent is the key to the past’, hasbeen largely discredited. The catastrophic processes associatedwith the atmosphere, hydrosphere,lithosphere and biosphere, such as riseand fall of sea levels, tsunamis,earthquakes and mass extinctions,have given rise to the concept ofcatastrophism where the past can beseen as the key to the present

United Nations — an organisation ofgovernments from around the world.It attempts to promote political, socialand economic stability around theworld. Its work is seen in the media asattempting to promote peace betweenconflicting nations. The UN wasestablished in 1945 by 51 countries

untied aid — see foreign aidupper catchment — the area of a river

catchment area where the river and its tributaries begin their journey tothe sea

urban — a term relating to a largepermanent settlement/built-up areawith a relatively dense populationcompared to its hinterland.

U


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Urban areas concentrate on theprovision of urban rather than ruralservices. Urban services include touristinformation, computer services, andcorporate headquarters rathern thanservicing farms. Examples of urban areas or urbansettlements include Sydney, London,Mexico City, Alice Springs andBallarat). Major urban areas have agreat concentration of people and

economic activity. These are known asurban agglomerations.

urban blight (see urban decay)urban consolidation — a process

whereby closer settlement occurs andis encouraged. An example of this is the case wheresingle dwellings on relatively largeblocks of land being replaced by twoor three houses, or even multipletownhouses. In both cases, the newhouses take advantage of existing

Major Urban Agglomerations

Urban Area Country Population

Tokyo Japan 27,242,000

Mexico City Mexico 16,908,000

Sao Paulo Brazil 16,792,000

New York USA 16,390,000

Bombay India 15,725,000

Shanghai China 13,659,000

Los Angeles USA 12,567,000

Calcutta India 12,118,000

Buenos Aires Brazil 11,931,000

Seoul Republic of Korea 11,768,000

Source: United Nations Population Division, 2000

Figure 57 � Examples of urban hierarchies

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infrastructure such as water andpower supplies

urban decay — (also known as urbanblight); the decline in the quality of anurban area such as the physical decayof buildings and roads. Also includedis the economic decline of an areawhere businesses close down or moveelsewhere, subsequent decline inemployment and income occurs, andsocial breakdown includes crime suchas vandalism

urban hierarchy — the network of, andrelationships between, urban placesreflecting population size andfunctional diversity (Figure 57). There are a number of models of urbanhierarchies including the central placetheory and rank size rule (see PrimateCity) The global urban hierarchy of todayhas seen the emergence of so-calledglobal cities such as New York, Londonand Tokyo. Their political, economic andtechnological power reaches all areasof the globe, whereas smaller centressuch as Melbourne and São Paulo havemuch smaller hinterlands, (or spheres

of influence) with fewer and lesssignificant interactions within theglobal urban hierarchy (see Christaller,W., rank size)

urbanisation — i) the increasing con-centration of urban activities in anarea; ii) the increasing percentage orproportion of people living in urbanareas of a country. The term level ofurbanisation is often used. For example the level of urbanisationmight be expressed as 82%. This means that of all the people in anarea, such as a country, 82% live inurban areas and only 18% live in ruralareas

urban models — (see concentric zonemodel, multiple nuclei model, sectortheory, Figure 58)

urban renewal — the upgrading ofurban areas (eg inner city areas) byeither demolition and replacement ofexisting buildings (development)and/or improving existing structures(renovation)

urban sprawl — the outward growth ofthe city, where residential/comm-ercial/industrial land use activityreplaces previously rural land

Figure 58 � Urban models

Source: W Andrews & J Fien eds, The urban environment, Prentice-Hall of Australia1981, page 115

1. CBD 2. wholesale/light manufacturing3. residential, low income 4. residential, middle income5. residential, high income 6. heavy manufacturing7. outlying business complex 8. residential suburb9. industrial suburb 10. commuter zone

Concentric zone model Sector model Muliple Nuleii model

1 1

18

2

2

2

3

3

3

4

4

4

5

5

5

67

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negedic

U-shaped valley — when a glaciercarves out a valley, as it slowly movesdownslope, the valley forms the shapeof a U. When these types of valleys are

filled with water from the oceanfollowing the melting of the glacier afiord is formed (see figure 28, V-shaped valley, )

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vapour pressure — ameasure of the internalpressure exerted by awater droplet. When thevapour pressure of thewater droplets in a body

of water exceeds that of the overlyingatmosphere, evaporation occurs. At low temperatures, vapour pressureincreases only slightly as temperatureincreases slightly but at hightemperatures vapour pressure inc-reases greatly with only slighttemperature increases. The significance of this is that smalltemperature increases in tropicalenvironments will lead to muchgreater rainfall than small temperatureincreases in areas of higher latitudesor altitudes (see atmosphere)

varve — an alternating sequence of athin layer of fine sediment and coursesediment within a sedimentarysequence. This is typically found in themeltwater of glaciers. The finesediment settles out indicating veryslow flow especially during winter orprolonged cold periods. This occursbecause most water is locked up as ice.During the warmer summer, the flowof this meltwater is much greater andso can carry larger and heaviersediment. This is because there ismuch more meltwater in the warmerseason. Sediment will eventually bedeposited. There is then a sequence offine and coarse sediment indicatingseasonal temperature rhythms. The sequence of varves can be used todetermine what the environment orclimate was like when these varveswere deposited (see figure 12, climatechange)

V-shaped valley — when rivers erodethe valley in which they are locatedthey tend to erode vertically

downward carving a V-shape into theland (see erosion , U-shaped valley)

vegetation — the plant cover of an area.Vegetation can be considered asindividual species (eg Eucalypts) or asan interacting community of a varietyof species (eg a rainforest)

veldt — extensive treeless grassland insouthern Africa

ventifact — a rock or stone that showsevidence of sand blasting or abrasionon its flat surfaces. It also shows sharpridges between the furrows created bythe abrasion. Ventifacts are common inarid environments where windtransports sand at high velocities (seeweathering)

verga — an atmospheric phenomenonwhereby precipitation (raindrops orice) evaporates as it falls through theatmosphere forming what appears tobe a ghostly cloud high up in theatmosphere (see evaporation,weathering)

vertical exaggeration — a measure ofhow much the vertical axis of a crosssection has been stretched orexaggerated in order to see the shapeof the land. Vertical exaggeration iscalculated as:

Vertical Scale (VS)

Horizontal Scale (HS)That is:

VS (of the cross section) eg 1 cm rep. 100m

HS (of the map from which the crosssection has been drawn) eg 1 cm rep 1000m

1

100

1

1000= 10

V


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vertical integration — a form ofbusiness expansion where a businessexpands forwards or backwards in theproduction process. For example, asteel manufacturer may expandbackwards by acquiring an iron orelease or coal mine (its raw materials);it may expand forwards by establishinga business to sell or even market itsproduct

vertical relief — along a transectvertical relief is a measure of theextremes in height between any twopoints — the highest point minus thelowest point along a transect includingthe two points on the transect

village — a nucleated rural settlementthat has a range of functions, such as achurch and local store, that are infrequent demand (see central place,hamlet)

viscosity — the tendency of a substanceto resist flow. An increase in viscosityimplies a decrease in flow; for examplea fast moving lava flow is said to have

low viscosity; a slow flowing lava is saidto be very viscous or to have highviscosity

viticulture — a type of agriculturewhere grapes are grown eventually forwine production

volcano — an opening in the Earth’scrust that has allowed magma to reachthe surface (see composite volcano,extrusion, shield volcano)

volcanic neck — the solidified magmawithin the vent or neck of a volcano.Weathering and erosion often stripssoil and debris from around the neckof the volcano exposing a tall, steepsided structure. The volcanic terrain ofThe Warrumbungle Mountains, NSWand The Glasshouse Mountains, QldAustralia has many volcanic necks

volcanic rock — rock formed fromvolcanic action such as thesolidification of lava forming basaltrock; another example is obsidian (avolcanic glass).

Figure 59 � The von Thuenen land use model

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Volcanic rock is a type of igneous rockthat has cooled quickly on the Earth’ssurface. As a result, the crystals thatmake up the rock are very small.Other types of igneous rock that havecooled more slowly have much largercrystals (see extrusion, volcano)

von Thuenen model — a model ofagricultural location theory developedby J.H. von Thuenen (Figure 59). Assuming a single market, surroundedby an isotropic surface, such asfarmland being uniformly flat and ofuniform fertility, and with transportcosts increasing uniformly in alldirections, the optimum location isdetermined for specific agriculturalland use types. This model includes the concept ofeconomic rent which is the returnreceived from working the land. A land use type will be economic in anarea where transport costs do not

exceed that return or revenuereceived. When transport costs andrevenue are equal economic return iszero. Beyond this point, a more extensiveland use type is more economic orprofitable. As a result, with a singleform of land use being carried out,such as market gardening, dairyingand wheat, land use becomes moreextensive the further from the market. A concentric zonal pattern of land useis said to develop on this isotropicsurface. However, because the model hasunrealistic assumptions, land usepatterns are complicated by suchfactors as variations in topography andbehavioural decisions by individuals.(see extensive farming/agricultural/land use, intensive farming/agricultural/land use)

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wadi — a dry river coursetypically found in aridareas. A wadi will flowonly after a briefrainstorm

Walker circulation —atmospheric circulation along theequatorial latitudes involving theascent over the Indonesian sector andthe subsidence over the easternPacific. The Walker circulation is not reallyone simple cell but a complex set ofvertical motions involving the wholeequatorial zone. When the Walker circulation is strongsea surface temperatures in theequatorial eastern Pacific are low,rainfall and cloudiness are low in thesame area, but high over Indonesiaand Australia. There are alsoassociated anomalies of weather andcirculation in many parts of the world.When the Walker circulation is weakthe reverse anomalies occur. Thestrength of the Walker circulationfluctuates irregularly but with a 2–5year period. Source: Climate Changeand Variability, A.B. Pittock et al p. 180C.U.P., 1978 (see atmsosphere, figure23, ENSO, general circulation,Southern Oscillation)

Wallace’s line — a line drawn by AlfredRussell Wallace to mark the boundarybetween distinctive fauna of the Asianand Australian continents. The lineseparates two classes of mammals –the predominantly marsupial ofAustralasia and the solely placental ofAsia. The line follows a deep channelsouth of the Philippines between theislands of Borneo and Sulawesi andthrough to between Bali and Lombok

Wallacea — the area making upthousands of islands between the edge

of the Australian continental shelf(Sunda Land) and the mainland; iebetween the Sunda and Sahulincluding the islands of Bali, Lombok,Flores and Timor. Wallacea was namedafter Alfred Russell Wallace whorecognised the distinctive Asian floraand fauna north of this area anddistinctive Australian flora and faunasouth of this area. The line marking theboundary between these two sets offlora and fauna is known as Wallace’sline

Walls of China — a landform resultingfrom the erosion of the lunette on theeastern side of Lake Mungo in theWillandra Lakes region of western NewSouth Wales, Australia (see lunette,figure 39)

warm front — the passage of a warmparcel of air overtaking colder moredense air. Just as with a cold frontprecipitation often results as air rises.However precipitation resulting fromthe passage of a warm front tends tolast for a longer period of time and tobe less intense than that resulting froma cold front. Warm fronts are not verycommon in Australia (see atmosphere,figure 50, figure 55)

water cycle — see hydrologic cyclewatershed — see catchment areawater table — the upper part of the

saturated zone of the regolith. Abovethe water table, evaporation is greaterthan the water received from groundwater flow. Below the water table theinput of ground water is greater thanthe rate of evaporation. The watertable occurs where these twoprocesses balance each other. The water table is normally very low indeserts because groundwater flow isvery low and evaporation is very high;whereas in wetter or more humid areas

W


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the water table is much higher (such asa metre below the surface). Riversindicate where the water table meetsthe surface

WaterWatch — a management programin which local communities becomeinvolved in monitoring the state oftheir environment with the objective ofpromoting environmental awarenessand improved environmental quality.Australian examples are Streamwatch(NSW) and Ribbon of Water (WesternAustralia)

wave height — the vertical distancebetween the wave crest and the wavetrough

wavelength — the horizontal distancebetween successive crests or successivetroughs — such as in ocean waves.Waves in the open ocean tend to havelong wavelengths; as they approachshallower water near land thewavelength decreases and the waveheight increases leading to thebreaking waves along the coastline

wave period — the time taken betweentwo successive wave crests or twosuccessive wave troughs

wave refraction — the bending of thewave front as water depth decreases —when wave depth is less than half thewavelength. As waves approach theshoreline at an angle wave depthdecreases reducing the speed of thatsection of wave; the rest of the wavemoves forward; so the wave appears tobend

WCED — see World Commission onEnvironment and Development

weather — the condition of the loweratmosphere in the short-term – over aday, a week, or even the past month.Weather including precipitation,temperature, winds and humidity (seeclimate, relative humidity)

weathering — the physical or chemicalbreakdown of materials into smallermaterials (physical weathering) orsimpler minerals (chemicalweathering). Examples include frostshattering, insolation weathering,oxidation and carbonation

weather map — see synoptic chartWeber, A — a German spatial geographer/

economist who, in 1905, proposed atheory of industrial location. He paid particular attention to the lossof weight and bulk associated with theprocessing of raw materials. He demonstrated that industries withlarge weight loss were resource-oriented. These industries tended tolocate near the resource beingprocessed (in order to reduce totalcosts)

Wegner, A — a German meteorologist/geologist who, in 1915, firstelaborated on the concept ofcontinental drift. He noted the remarkable similaritybetween the geology, flora as well asthe shapes of the opposing coasts ofAfrica and South America. He latersuggested that a supercontinent,Pangaea, began to break up about 200million years ago. His then controversial theory did notgain acceptance until the late 1960s.The weight of supportive evidenceconfirmed the concept of continentaldrift. In this same period two otherEarth Scientists, Harry Hess and J. Tuzo Wilson, suggested the methodof such drift with the mechanisminvolving crustal plates and mid-oceanridges. The concepts of plate tectonics andsea floor spreading were born

West Antarctica — that part of theAntarctic continent that extends alongits Southern and Indian Oceancoastlines from the Ross Ice Shelf tothe Ronne Ice Shelf. West Antarcticaforms the bulk of the area of Antarctica(see East Antarctica)

West Asia — that part of Asia comprisingAfghanistan, Tajikistan, Kyrgyzstan,Kazakhstan, Uzbekistan, Turkmenistan,Azerbaijan, Iran, Iraq, Syria, Jordan,Israel, Saudi Arabia, Yemen, Oman,United Arab Emirates, Qatar, Bahrainand Kuwait (see South Asia, SoutheastAsia, East Asia and North Asia)

aryewhy

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West Bank — disputed territorybetween Israel and Jordan east of theJordan River. Following the wars of1967 and 1973, Israel occupies muchof the West Bank with Israelipopulations replacing those ofPalestinians. The Golan Heights to thenortheast of the Sea of Galilee is alsoin dispute between Israel, Lebanonand Syria

west wind drift — a slow easterlyflowing ocean current driven by thewesterly winds between latitudes 45ºS and 55ºS approximately

wetlands — any area of flat land that ispermanently or temporarily covered byshallow water eg mangroves andswamps (Figure 60 colour). Wetlandsare common along coastal areas such asin estuaries, where the rise and fall oftides lead to inter-tidal mangroves.Riverine wetlands, which arepermanently under water, form alongrivers. Wetlands are also located alongthe edges of, and within, inland lakes

White Australia Policy — the namegiven to the Federal Governmentpolicy of the early to mid twentiethcentury that excluded immigration ofpeople of non-British or Europeandescent into Austraia

WHO — World Health Organisationwilderness — an area which is in its

natural state with no human activitywindchill — the cooling effect of wind

on a surface. The surrounding airtemperature might be 8°C but becauseof the presence of a wind the actualtemperature felt by the skin might be3°C this is because the windevaporates moisture from the skin andevaporation is a cooling process. The difference in air temperature andthat actually experienced is the resultof the ‘windchill factor’ (seeatmosphere)

wind tunneling — the acceleration ofwind caused by its path betweenbuildings — such as between tallbuildings within the CBD

wind power — the generation ofelectricity by windmills harnessing the

power of winds by turning turbines.The generation of wind power is apollution-free, renewable form ofenergy. It is used to supplement moretraditional energy sources in areaswhere constant and reliable windsblow unimpeded by mountainbarriers eg latitude 40°–50° North andSouth (southwestern WesternAustralia, the Netherlands in northernEurope and Chile in South America)

wind rose — a type of graph indicatingthe direction from which winds blowtowards a point. In more detailedwind roses, wind strength and thepercentage of times that winds blowfrom a particular direction are given

winter solstice — an event that is theresult of the Earth’s revolution aroundthe Sun. In the Southern Hemisphere,this event occurs 21-22 June. At thistime the Sun is directly overhead atlatitude 23½°N (Tropic of Cancer); thisis known as the shortest day of theyear in the Southern Hemisphere. Thearea south of the Antarctic Circle(latitude 66½°S) receives no directsunlight

Wollemi Pine — a new species of tree,discovered in 1994, northwest ofSydney, NSW. The tree grows up to 35metres high. The species has survivedfor over 100 million years

woodchipping — the process of cuttingtrees into smaller units for use inindustry

World Bank — an international agency.The World Bank provides long termloans to countries that cannot paycommercial rates of interest (seeInternational Monetary Fund)

world city — a major city of the worldwith international linkages andinfluence such as significant economicand political ties; such cities includeNew York, London and Tokyo. Thesecities occupy a distinctive niche as aresult of their role as political andfinancial control centres. Their statusis confirmed by concentrations ofproducer services such as education,research and development, banking,accounting, legal services, advertisingand real estate

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World Commission on Environmentand Development — a UnitedNations organisation established bythe United Nations General Assemblyin 1983. The WCED is concerned withidentifying changes in, and threats to,environmental quality and the qualityof life of people around the world. Itsfamous 1987 publication, OurCommon Future, showed andexplained to the world the state of theplanet and the need for effective socialand political action and cooperation inorder to halt the global degradation ofboth natural resources and the qualityof people lives. The WCED is morecommonly known as the ‘BrundtlandCommission’ after its chairperson GroHarlem Brundtland, former PrimeMinister of Norway

World Conservation Strategy —throughout the 1980s and 1990s andinto the 21st Century people’sattention has increasingly beenfocused on the plight of naturalresources and the quality of thenatural environment in which theylive. A World Conservation Strategywas published in the early 1980s topromote the wise use of thebiophysical environment and itsresources following principles such asenvironmental sustainability. The WCS provided a strategy forgovernments, industry, communitiesas well as individuals to better utilisenatural resources and to ensure theirlong-term viability (see NationalConservation Strategy, sustainabledevelopment, sustainable yield)

World Conservation Union — seeIUCN

world economy — the capitalisteconomic system that has emergedsince the Middle Ages linking

countries into a global economy inwhich different countries occupydifferent positions in terms of levels ofdevelopment, political systems andresource endowment

World Heritage List/site — in 1972 TheConvention Concerning theProtection of the World’s Cultural andNatural Heritage (The World HeritageConvention) was adopted by UNESCO.The Convention aims to protect sitesof significance that are recognisedworldwide (not just by a country) andare of a concern to all people. A WorldHeritage List has been established.Over 400 sites worldwide have beendesignated as World Heritage Sites.These include the Grand Canyon USA,The Great Wall of China, andStonehenge in England. In Australia,World Heritage sites are: the GreatBarrier Reef (1981), Kakadu NationalPark (in three stages 1981, 1987,1992), Willandra Lakes Region (1981),Lord Howe Island Group (1982),Tasmanian Wilderness (1982 and twicein 1989), Australian East CoastTemperate and Subtropical RainforestPark (1986, 1994), Uluru-Kata TjutaNational Park (1987, 1994), WetTropics of Queensland (1988), SharkBay (1991), Fraser Island (1992),Australian Fossil Mammal Sites:Riversleigh/Narracoorte (1994), Heardand MacDonald Islands (1997), andthe Greater Blue Mountains Area(2000)

World Trade Organisation — aninternational organisation with theaim of encouraging international tradevia the removal of trade barriers

WTO — see World Trade OrganisationWWF — World Wide Fund for Nature

(formerly the World Wildlife Fund)

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negedic

Xanthorrhoea — a nativeAustralian plant morecommonly known as a‘Grass Tree’, ‘KangarooTail’ and ‘Black Boy.’ Itis not a grass or a tree

but is more closely related to the lily.The Xanthorrhoea is well adapted tothe dry, exposed environments such ason the top of exposed plateausurfaces. It is well adapted to fire withits thick bark insulating its interior. Itsometimes burns to ground level butsprouts immediately after rain

xanthozem — a deep yellow highlystructured clay soil with increasingclay content with depth dominated bysesquioxides. It has a differentiatedprofile — upper clay-loam A-horizonto a medium-heavy clay B-horizon,strongly pedal with an acid pH (seekraznozem, residual site)

xenoalpine — those insects in highaltitude areas that have ‘accidentally’found their way into alpine areas butdo not become established

xenolith — a piece of surrounding rock(called country rock) incorporatedinto an intrusion such as a dyke

xeromorphic — possessing featuressimilar to xerophytes

xerophyte — a plant adapted to dryconditions such as in aridenvironments. Examples includecactus and spinifex (see plantsuccession, sere)

xerophytic — having the characteristicsof being able to adapt to dryconditions (see arid environment,xerophyte)

xerosere — the stages in plant succ-ession in an arid environment

xerothermic — a warm-dry periodXi’an — capital of Shaanxi Province in

central China. This is the site at whichthe buried terracotta warrior ‘army’ ofthe emperor Qin was discovered in1974

x-ray art — a style of artwork originallypractised by Aboriginal groups inAustralia especially of animals in theirimmediate environment. Typically, thespine and other bones and internalorgans are shown as well as theoutlined exterior of the figure

X


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Yanomami — the largestIndian nation in Brazil.Initial substantivecontact with Europeanswas in the 1950s. TheYanomami people have

been in conflict with the BrazilianGovernment since the 1970s due to aproposal to open up the Amazon via anational highway through Yanomamitraditional land. During this time,disease decimated the indigenouspeople. In 1992 however the BrazilianGovernment set aside 94,000 km2 ofnorthern Brazil for the Yanomamination (see indigenous people,maloca)

Yap — one of the Caroline Islands in thewestern Pacific Ocean — part of theUS-administered Trust Territories ofthe Pacific Islands

yardang — a landform typical of aridenvironments. Wind carries sand justabove the ground which, in turn,abrades the surface forming longgrooves in the rock surface with sharpridges between these grooves (seeabrasion)

yield — the output or productionexpressed in relation to a unit ofinput. For example in relation

agriculture, the amount of producefrom crops or cattle may be expressedin terms such as 20 kilograms perhectare (20kg/ha), or 5 litres per day;100 kg per km2 (see sustainable yield)

young population — the population ofa community, such as a country, isconsidered ‘young’ if the proportionof young people (ie those under 15years of age) is greater than the 30% ofthe total population AND theproportion of older people (aged over65 years of age) is less than 6% of thetotal population. Many developingcountries have young populations as aresult of factors such as rising birthrates. The rapidly declining birth ratesof developing countries such asAustralia is leading to ageingpopulations (see old population,population, population pyramid)

Yucatan Peninsula — an area of Mexicothought to be the site of a large meteorimpact approximately 65 million yearsago. The resultant impact is suspectedto have led to a major globalextinction event that included thedinosaurs

Yunnan — a Province in southwestChina

Y


aryewhy

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zenith — the point inspace that is verticallyoverhead. The pointdirectly above an obser-ver at 90°N is called thezenith; the point at 90°S is called the nadir

zero tillage — where the land is not‘tilled’ (such as ploughed) before theplanting of crops

zetaform beaches — along manycoastlines headlands are separated bylong sandy beaches which areasymmetrical when viewed from above– taking on a half-heart shape (Figure61 colour). On beaches that areaffected by constant swell, waves arerefracted around headlands. A verytight curve near one headland contrastswith a long sweeping beach towardsthe other headland (see waverefraction)

zonal flow — any flow of water or aircirculating along a straight line such asa line of latitude. The circulation ofwesterly winds between latitide35°–55° North and South and the flowof air along the equator from east towest are examples of zonal flow

zone of aeration — the zoneimmediately below the ground surfacein which the spaces between soilparticles are partially filled with airand partially with water

zone of saturation — the zone belowthe ground surface in all spacesbetween soil particles are filled withwater. The top of the zone ofsaturation is called the water table.The water contained within the zoneof saturation is called groundwater

zone of transition — an area or zonethat is experiencing gradual change.For example, the transition that occursfrom a dominantly rural todominantly urban on the rural-urbanfringe. The term was originally applied

to the area around the CBD of theconcentric zone model representing amix of industrial, commercial andolder residential land use. It is nowmore commonly used to describeareas of gradual change from oneextreme to another such as thetransition from an arid climate to amore humid climate

zonal model of soil formation — amodel suggesting that soils formunder so called ‘normal’ conditions ofslope, drainage and rock-type andshow broad similarities across theglobe. These reflect patterns ofclimate and vegetation on a worldscale – eg chernozems of thegrasslands of North America and theUkraine steppe and the podsolisedsoils of the temperate forests. Thezonal model of soil formation isincreasingly being challenged as aneffective tool to describe and accountfor soil types because of its circulararguments. More recent modelshighlight the significance of local soil-forming factors such as parentmaterial, slope and biological action.Similarly local earth-surface processessuch as soil creep and slopewash areaddressed rather than verticallyoperating processes of eluviation andilluviation being exclusively treated(see azonal soil, duplex soil, intrazonalsoil, podsol)

zonda — a warm, humid wind from thenorth in Argentina and Uruguay

zoogeography — the study of thelocation and distribution of animalsover the Earth

zoophyte — an animal that resembles aplant (eg a coral polyp)

ZPG — zero population growth; whereparents have only the number ofchildren needed to maintain theexisting population number

Z


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WORLD RECORDS

ATMOSPHERE

Highest Average Annual Rainfall Mawsynram (India) 11,873 mmLowest Average Annual Rainfall Antfagasta (Chile) 0�0.1 mm

Driest Continent Antarctica, less than 50mm per annumHighest recorded Temperature Azizia (Libya) 58°CLowest Recorded Temperature Vostok (Antarctica) -89.2°CMost Consecutive Sunny Days St. Petersburg (Russia) 768 between

1967 and 1969Most Rainy Days per year Mt Wai�ale�ale (Hawaii) up to 350 rainy days

Least Sunshine on Earth South Pole (182 days without sunshine)Highest Average Annual Rainfall

Recorded in Australia Babinda (Queensland) 4573mmHighest Recorded

Temperature in Australia Cloncurry (Queensland) 53.1°CLowest Recorded

Temperature in Australia Charlotte Pass (NSW) -23°CWindiest Place Mt Washington (USA) winds 371 km/hr

LITHOSPHERE

Largest Continent Asia 43,608,000 km3

Largest Desert Antarctica, 14.9 million km2

Largest Hot Desert Sahara Desert (North Africa) 9,269,000 km2

Highest Mountain Mt Everest (Tibet/Nepal) 8848 mHighest Marine Mountain Mauna Kea (Hawaii) 10,205 m (of which 4205m is

above sea level)Highest Plateau Tibet 4875 m

Largest Delta Ganges/Brahmaputra Delta (Bangladesh) 75,000 km2

Largest Island Greenland (North Atlantic Ocean) 2,175,000 km2

Largest Sand Island Fraser Island (Queensland, Australia) 1662 km2

Largest Archipelago Indonesia, over 13,000 islandsLargest Active Volcano Mauna Loa (Hawaii) 6000 km2

Largest Cave Sarawak Chamber (also Lubung Nasib Bagus)(Malaysia) 700 m long, 70 m high with an averagewidth of 300m

Longest Gorge Grand Canyon (USA) 446 kmLongest Fiord Nordvest Fiord (Greenland) 313 km

Longest Mountain Range Andes (South America) 7240 kmDeepest Point on Earth Mariana Trench (western Pacific Ocean) 11,032 m

Lowest Point on theEarth�s Surface Dead Sea (Israel) 398 m below sea level

Highest Mountain on theAustralian Mainland Mt Kosciuszko (NSW) 2228 m

Highest Mountain onAustralian Territory Big Ben (Heard Island) � Mawson Peak at 2745 m

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HYDROSPHERE

Longest River Nile River (Barundi to Egypt) 6670 kmLargest River Discharge Amazon River (Brazil) 6500 km3 per year

Highest Waterfalls Angel Falls (Venezuela) 807 mLargest Freshwater Lake Caspian Sea (Kazakstan, Turkmenistan, Iran,

Azerbaijan, Russia) 371,800 km2

Deepest Lake Lake Baykal (Russia) 1637 mHighest Lake Lake Titicaca (Peru/Bolivia, South America) 3810 m

above sea levelLargest Atoll Christmas Island (Kiritimai since 1985) 94 km2

Largest Ocean Pacific Ocean, 166,241,700 km2

Smallest Ocean Arctic Ocean, 13,223,700 km2

Largest Marine Park Great Barrier Reef Marine Park (350,000 km2)Tallest Geyser Steamboat Geyser (Yellowstone National Park, USA)

60�120 mLongest Glacier on Earth Lambert Glacier (Antarctica) 3000 km

Longest River in Australia Murray-Darling 3750 km

BIOSPHERE

Largest National Park in Australia Kakadu National Park (Northern Territory) 19,800 km2

Largest Flower Rafflesia arnoldii (Indonesia/Malaysia) 91 cm flowerbloom

Largest Rainforest area Amazon BasinBiggest Animal on Earth Blue Whale

Fastest Land Mammal CheetahTallest Tree Mendocino Tree, California (112 m)

Oldest Living Tree Redwood, California (USA) � 72 m

URBAN

Largest Country by area Russia, 17,078 005 km2

Smallest Country by area Vatican City (Rome) 0.4 km2

Largest Country by Population China, 1.2 billion peopleSmallest Country by Population Vatican City (Rome) 834 people

Most Densely Populated Country Monaco (France) 14,237 people per km2

Least Densely Populated Country Western Sahara (Africa) 0.7 people per km2

Most densely Populated Island Java (Indonesia) 898 people per km2

Largest City by Population Tokyo (Japan) 28,447,000Most Northern Capital City Reykjavik (Iceland) 64°09'N 21°57'WMost Southern Capital City Wellington (New Zealand) 41°18'S 174°47'E

Longest Railroad Trans-Siberian Railway (Russia) 9437 kmLongest Fence Dingo Fence (Australia)

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SITES OF INTERNATIONAL SIGNIFICANCE

Seven Wonders of the World

Pyramids of EgyptTemple of Artemis (Diana) at EphesusThe Colossus of RhodesThe Mausoleum at HalicarnassusThe Phaos or Lighthouse of AlexandriaThe Statue of Zeus at OlympiaThe Hanging Gardens of Babylon

Seven Wonders of the Ancient World

Temple of Abu Simbel (Egypt)Temple of Angkor Wat (Cambodia)Monoliths of Rapa Nui (Easter Island)Throne of Persepolis (Iran)Taj Mahal (India)Leaning Tower of Pisa (Italy)Great Wall of China

World Heritage Sites(Australia)

Great Barrier Reef (1981)Kakadu National Park (1981, 1987, 1992)Willandra Lakes region (1981)Western Tasmania Wilderness NationalParks (1982, 1989)Lord Howe Island Group (1982)Ulura-Kata Tjuta National Pak (1987,1994)Central Eastern Rainforest reserves(1986, 1994)Wet Tropics of Queensland (1988)Shark Bay (1991)Fraser Island (1992)Riversleigh/Naracoorte Fossil MammalSites (1994)Heard and MacDonald Islands (1997)Macquarie Island (1997)Blue Mountains (2000)

Seven Natural Wonders of the World

Himalayas and Mt EverestVictoria FallsGrand CanyonGreat Barrier ReefNiagara FallsParicutín (volcano)Iguaçu Falls

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CONVERSION TABLES

Abbreviations Prefixes

millimetre mm mega M one million 106

centimetre cm kilo k one thousand 103

metre m hecto- h one hundred 102

kilometre km deka da ten 101

gram g deci- d one tenth 10-1

kilogram kg centi- c one hundredth 10-2

litre l milli- m one thousandth 10-3

millilitre ml micron one millionth 10-6

kilolitre klhectare hahectopascal hPa

Length

1 millimetre � 0.03937 inches1 centimetre 10 mm; 0.394 inches

1 metre 100 cm; 39.37 inches; 3.281 feet; 1.094 yards1 kilometre 1000 m; 0.621 miles; 1094 yards; 3218 feet

1 inch 2.54 cm; 0.0245 m1 foot 0.304 m1 yard 0.9144 m

1 statute mile 1609 m; 1.609 km; 5280 feet1 nautical mile 1852 m; 1.85 km; 6076 feet

1 fathom 1.83 m; 6 feet

Area

1 hectare = 10,000km2 (100m x 100m) = 2.47 acres

1 kilometre = 10,000,000 m2

1cm2 = 0.1550 inches2

1m2 = 10.76 feet2

= 1.2 yards2

1km2 = 0.3861 miles2

1 inch2 = 6.452 cm2

1 foot2 = 929 cm2

1 acre = 4047 m2

1 mile2 = 2.590 km2

= 2,590,000 m2

= 640 acres

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Velocity

1 knot = 1 nautical mile per hour= 1 metre per second= 3.328 feet per second= 2.24 miles per hour

1 kilometre/hour = 0.621 miles/hour1 mile/hour = 1.61 kilometres/hour

Volume

1cm3 = 0.06102 inches3; 0.000001m3

1metre3 = 435.31 feet3; 1.308 yards3

1 kilometre3 = 0.239 metres3

1 inch3 = 16.39 cm1 foot3 = 0.02832 metres3

1 yard3 = 0.7646 metres3

1 mile3 = 4.17 kilometres3

Liquid volumeone imperial gallon = 4.55 litres

Mass

1 gram = 0.0353 ounces100 grams = 3.5 ounces 1 kilogram = 1000 grams; 2.20 pounds

1 tonne = 1000 kilograms; 0.984 tons1 ounce = 28.3 grams1 pound = 454 grams

1 ton = 1.02 tonnes

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Temperature

Freezing point of water = O°C= 32°F

Boiling point of water = 100°C= 212°F

°C = 5/9 x (°F - 32)°F = 9/5 x °C + 32

Scale Equivalents

Ratio Representative StatementFraction

1:10 1/10 one centimetre represents 10 cm (or 0.0001 km)

1:100 1/100 one centimetre represents 1 metre (or 0.001km)

1:1000 1/1000 one centimetre represents 10 metres (or 0.01 km)

1:10,000 1/10,000 one centimetre represents 100 metres (or 0.1 km)

1:100,000 1/100,000 one centimetre represents 1000 metres (or one kilometre)

1:1,000,000 1/1,000,000 one centimetre represents 10,000 metres (or 10 kilometres)

Ratio Statement

1: 100,000 one centimetre represents one kilometre


Line scale0 1 2 3 4 5

kilometre

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POPULATION OF THE COUNTRIES OF THE WORLDAND THEIR RANKING BY SIZE, 1999 AND 2050

Country or area Population (thousands) Ranking1999 2050 1999 2050

World 5,978,401 8,909,095Afghanistan 21,923 61,004 45 25Albania 3113 4322 129 132Algeria 30,774 57,731 34 29American Samoa 66 201 202 191Andorra 75 165 198 194Angola 12,479 36,901 61 50Anguilla 8 13 221 220Antigua and Barbuda 67 79 201 205Argentina 36,577 54522 31 32Armenia 3525 3996 125 135Aruba 98 347 191 182Australia (1) 18,705 25,761 51 63Austria 8177 7094 85 112Azerbaijan 7697 9981 88 95Bahamas 301 485 173 173Bahrain 606 992 161 160Bangladesh 126,947 212,495 8 8Barbados 269 288 177 186Belarus 10,274 8330 73 102Belgium 10,152 8918 75 99Belize 235 477 178 174Benin 5937 15,620 100 77Bermuda 64 82 203 203Bhutan 2064 5687 140 116Bolivia 8142 16,967 86 72Bosnia and Herzegovina 3839 3767 118 137 Botswana 1597 2798 145 143Brazil 167,988 244,230 5 7British Virgin Islands 21 46 213 207Brunei Darussalam 322 528 172 171Bulgaria 8279 5673 84 117Burkina Faso 11,616 35,491 63 52Burundi 6565 15,571 94 78Cambodia 10,945 20,700 68 68

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Cameroon 14,693 37,290 59 48

Canada 30,857 42,311 33 41

Cape Verde 418 869 168 164

Cayman Islands 37 102 208 201

Central African Republic 3550 7689 124 108

Chad 7458 19,693 89 69

Channel Islands 152 173 186 193

Chile 15,019 22,215 58 65

China 1,266,838 1,477,730 1 2

China Hong Kong SAR (2) 6801 6664 93 114

Colombia 41,564 71,550 27 22

Comoros 676 1577 159 150

Congo 2864 8597 131 101

Cook Islands 19 28 214 215

Costa Rica 3933 7195 117 111

Côte d'Ivoire 14,526 30,470 60 58

Croatia 4477 3673 113 138

Cuba 11,160 11,095 65 90

Cyprus 778 913 157 163

Czech Republic 10,262 7829 74 106

Dem. People's Rep. of Korea 23,702 30,770 41 57

Dem. Republic of the Congo 50,335 160,360 24 10

Denmark 5282 4793 105 123

Djibouti 629 1346 160 155

Dominica 71 79 200 204

Dominican Republic 8364 12,265 83 85

East Timor 871 1387 154 154

Ecuador 12,411 21,190 62 67

Egypt 67,226 114,844 15 16

El Salvador 6154 11,237 97 89

Equatorial Guinea 442 1122 165 159

Eritrea 3719 9085 121 98

Estonia 1412 927 146 162

Ethiopia 61,095 169,446 18 9

Faeroe Islands 43 34 206 213

Falkland Islands (Malvinas) 2 3 224 224

Fiji 806 1310 156 156

Finland 5165 4898 106 121

POPULATION OF THE COUNTRIES OF THE WORLD AND THEIR RANKING BY SIZE, 1999 AND 2050Country or area Population (thousands) Ranking

1999 2050 1999 2050

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France 58,886 59,883 20 26

French Guiana 174 581 184 170

French Polynesia 231 388 179 180

Gabon 1197 2682 149 146

Gambia 1268 2773 148 144

Gaza Strip 1077 4772 152 124

Georgia 5006 5180 107 119

Germany 82,178 73,303 12 21

Ghana 19,678 51,802 49 35

Gibraltar 25 18 212 219

Greece 10,626 8233 71 104

Greenland 56 63 205 206

Grenada 93 115 194 197

Guadeloupe 450 601 164 167

Guam 164 266 185 188

Guatemala 11,090 27,165 66 61

Guinea 7360 16,348 90 75

Guinea-Bissau 1187 2685 150 145

Guyana 855 1166 155 157

Haiti 8087 15,174 87 79

Holy See (3) -- 1 227 227

Honduras 6316 13,920 96 82

Hungary 10,076 7488 76 109

Iceland 279 341 175 183

India 998,056 1,528,853 2 1

Indonesia 209,255 311,857 4 5

Iran (Islamic Republic of) 66,796 114,947 16 15

Iraq 22,450 54,916 43 31

Ireland 3705 4710 122 128

Isle of Man 78 104 196 200

Israel 6101 9440 99 97

Italy 57,343 41,197 22 44

Jamaica 2560 3801 135 136

Japan 126,505 104,921 9 17

Jordan 6482 16,547 95 73

Kazakstan 16,269 18,665 54 70

Kenya 29,549 51,034 35 37

Kiribati 82 155 195 195


1999 2050 1999 2050

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Kuwait 1897 3527 143 140

Kyrgyzstan 4669 7375 111 110

Lao People's Dem. Republic 5297 13,344 104 83

Latvia 2389 1628 138 149

Lebanon 3236 5169 128 120

Lesotho 2108 4766 139 125

Liberia 2930 10,010 130 94

Libyan Arab Jamahiriya 5471 11,005 101 91

Liechtenstein 32 42 210 210

Lithuania 3682 2967 123 142

Luxembourg 426 430 167 176

Macau 467 488 163 172

Madagascar 15,497 40,438 57 46

Malawi 10,640 29,008 69 60

Malaysia 21,830 36,989 46 49

Maldives 278 680 176 166

Mali 10,960 31,353 67 56

Malta 386 421 171 178

Marshall Islands 62 182 204 192

Martinique 392 457 170 175

Mauritania 2598 6585 134 115

Mauritius (4) 1150 1440 151 153

Mexico 97,365 146,645 11 11

Micronesia (Fed. States of) 116 254 189 189

Monaco 33 41 209 211

Mongolia 2621 4398 133 130

Montserrat 11 11 218 221

Morocco 27,867 45,434 37 39

Mozambique 19,286 42,923 50 40

Myanmar 45,059 64 890 26 23

Namibia 1695 3023 144 141

Nauru 11 24 219 217

Nepal 23,385 49,320 42 38

Netherlands 15,735 14,156 55 81

Netherlands Antilles 215 267 180 187

New Caledonia 210 332 181 184

New Zealand 3828 5248 120 118

Nicaragua 4938 11,600 108 87


1999 2050 1999 2050

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Niger 10,400 32,029 72 54

Nigeria 108,945 244,311 10 6

Niue 2 2 225 225

Northern Mariana Islands 74 402 199 179

Norway 4442 4758 114 126

Oman 2460 8310 136 103

Pakistan 152,331 345,484 6 4

Palau 19 45 215 208

Panama 2812 4263 132 133

Papua New Guinea 4702 9515 110 96

Paraguay 5358 12,565 103 84

Peru 25,230 42,292 38 42

Philippines 74,454 130,893 14 12

Pitcairn (5) -- -- 228 228

Poland 38,740 36,256 30 51

Portugal 9873 8137 77 105

Puerto Rico 3839 4710 119 127

Qatar 589 844 162 165

Republic of Korea 46,480 51,275 25 36

Republic of Moldova 4380 4506 116 129

Reunion 691 959 158 161

Romania 22,402 16,419 44 74

Russian Federation 147,196 121,256 7 14

Rwanda 7235 16,008 92 76

Saint Helena (6) 6 10 223 222

Saint Kitts and Nevis 39 36 207 212

Saint Lucia 152 242 187 190

Saint Pierre and Miquelon 7 8 222 223

Saint Vincent and Grenadines 113 140 190 196

Samoa 177 351 183 181

San Marino 26 30 211 214

Sao Tome and Principe 144 297 188 185

Saudi Arabia 20,899 54,461 48 33

Senegal 9240 23,135 80 64

Seychelles 77 115 197 198

Sierra Leone 4717 10,994 109 92

Singapore 3522 4015 126 134

Slovakia 5382 4836 102 122


1999 2050 1999 2050

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Slovenia 1989 1487 142 152

Solomon Islands 430 1130 166 158

Somalia 9672 31,835 78 55

South Africa 39,900 52,514 28 34

Spain 39,634 30,226 29 59

Sri Lanka 18,639 25,923 52 62

Sudan 28,883 59,176 36 27

Suriname 415 588 169 169

Swaziland 980 2436 153 147

Sweden 8892 8661 82 100

Switzerland 7344 6745 91 113

Syrian Arab Republic 15,725 34,490 56 53

Tajikistan 6104 11,293 98 88

TFYR Macedonia (7) 2011 2302 141 148

Thailand 60,856 74,188 19 20

Togo 4512 12,104 112 86

Tokelau 1 2 226 226

Tonga 98 110 192 199

Trinidad and Tobago 1289 1543 147 151

Tunisia 9460 14,983 79 80

Turkey 65,546 100,664 17 18

Turkmenistan 4384 7715 115 107

Turks and Caicos Islands 16 44 216 209

Tuvalu 11 28 220 216

Uganda 21,143 64,850 47 24

Ukraine 50,658 39,302 23 47

United Arab Emirates 2398 3615 137 139

United Kingdom 58,744 56,667 21 30

United Rep. of Tanzania 32,793 80,584 32 19

United States of America 276,218 349,318 3 3

United States Virgin Islands 94 86 193 202

Uruguay 3313 4362 127 131

Uzbekistan 23,942 40,565 39 45

Vanuatu 186 428 182 177

Venezuela 23,706 42,152 40 43

Viet Nam 78,705 126,793 13 13

Wallis and Futuna Islands 14 21 217 218

Western Sahara 284 591 174 168


1999 2050 1999 2050

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Yemen 17,488 58,801 53 28Yugoslavia 10,637 10,548 70 93Zambia 8976 21,204 81 66Zimbabwe 11,529 18,139 64 71

Source: United Nations Population Division.

(1) Including Christmas Islands, Cocos (Keeling) Islands and Norfolk Island.(2) As of 1 July 1997, Hong Kong became a Special Administrative Region (SAR)

of China.(3) For Vatican City State. The population of the Vatican City State was under

500 persons in 1999.(4) Including Agalega, Rodrigues and St. Brandon.(5) The population of Pitcairn was 47 persons in 1999 and 2050.(6) Including Ascension and Tristan da Cunha.(7) The former Yugoslav Republic of Macedonia.

Source: United Nations Population Division, The World at 6 Billion, United Nations,1999, pages 12-18


1999 2050 1999 2050

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