chapter two

Chapter Two

Population

Introduction

• Population is studied to provide a basis of understanding issues in Human Geography

• Population is important for three reasons:– More people are alive today– Population increased faster in the 2nd half of the 20th

century than ever before– Almost all population growth is in LDC’s

• Demography is the study of population growth and it looks at how people are spatially distributed by age, gender, occupation, fertility, health, etc…

Key Issue #1: Where is the World’s Population Distributed?

I. Population Concentrations• 2/3 of the world’s population (6 ¾ billion) are

in four regions: – East Asia– South Asia– Southeast Asia– Western Europe


• 2/3 of the world’s population live with in 300 miles of an Ocean

• The four population clusters are all:– low-lying areas– have fertile soil– temperate climates


East Asia:• 1/5 of the world’s population• China, Koreas, Japan, & Taiwan• 5/6 live in China (the most populous country

in the world)• Most people are farmers in rural areas


South Asia:• 1/5 of the world’s Population• India, Pakistan, Bangladesh, Sri Lanka• India is the 2nd most populous country in the

world• Most people are farmers in rural areas


• Southeast Asia:• Indonesia, Papua New Guinea, & the

Philippines• Europe:• 1/9 of the world’s population & 3rd largest

population cluster in the world• ¾ of Europe’s inhabitants live in cities


Other Population Clusters:• Largest population concentration in the

Western Hemisphere is the northeastern US & southeastern Canada – 2% of the world’s population

• Most Americans are urban dwellers• West Africa 2% of the world’s population –

mostly in Nigeria


II. Sparsely Populated Regions• Ecumene is the portion of the Earth’s surface

occupied by permanent human settlement• Dry Lands:• 20% of the Earth’s surface is too dry for farming• People adapt by using irrigation, raise animals like

Camels, & settle for cultivation of natural resources such as oil

• Wet Lands• The rain & heat hinders agriculture


• Cold Lands:• Polar regions• Permafrost prevents agriculture, few animals

can survive, & few humans can live here• High Lands:• Few people live at high elevations with the

exception of areas in Latin America & Africa


III. Population Density• Density (# of people occupying an area of

land) is looked at by:– Arithmetic Density,– Physiological Density– Agricultural Density


Arithmetic Density:• Arithmetic Density is the total number of people

divided by the total area of land aka population density

• Calculated by the total population & total land area• Varies within individual countries• Enables geographers to compare the number of

people trying to live on a given peace of land in different regions of the world


Physiological Density:• Physiological Density the number of people

supported by a unit area of arable land• The higher the physiological density, the

greater the pressure on the people to produce enough food

• Looks at the relationship between the size of a population & the availability of resources


Agricultural Density• Agricultural Density ratio of the number of

farmers to the amount of arable land• helps account for economic differences• MDC’s have a lower agricultural density than

LDC’s

Key Issue #2: Where has the World’s Population Increased

Crude means we are concerned with society as a whole rather than a refined look at individuals or groups

I. Natural Increase:• Geographers most frequently measure population

change in a country/world as a whole through three measures:

• Crude Birth Rate (CBR) total # of live births in a year for every 1000 people EX: CBR of 20 means 20 babies are born for every 1000 people


• Crude Death Rate (CDR) total # of deaths in a year for every 1000 people alive in a society

• Natural Increase Rate (NIR) the % by which a population grows in a year. It is computed by subtracting CDR from CBR – this excludes migration– About 80 million people are added to the world

annually– Doubling Time the number of years needed to double a

population assuming a constant rate of natural increase


II. Fertility:• The CBRs are mostly in sub-Saharan Africa• Total Fertility Rate (TFR) average number of

children a woman will have in her childbearing years (15-49)

• TFR attempt to predict the future behavior of individual women in the world

•


III. Mortality:• Infant Mortality Rate (IMR) is the annual

number of deaths of infants under 1 year of age compared to total live births– The highest rate of IMRs are in sub-Saharan Africa– The lowest rates are in Western Europe– IMR reflect a country’s health-care system– Minorities in the US have IMRs twice as high as

the national average comparable to levels in Latin America & Asia


• Life Expectancy measures the average number of years a newborn infant can expect to live at current morality levels– Highest in wealthy countries– People can live into their 70’s in Western Europe

compared to their 40’s in sub-Saharan Africa

Key Issue # 3: Why is Population Increasing at Different Rates in Different Countries?

I. The Demographic Transition the process of change in a society’s population from a condition of high CBR & CDR & low NIR to a condition of low CBR & CDR & high NIR

• The process with several stages and every country is in one of them. There are four stages


• Stage 1: Low Growth– During this period people depended on hunting &

gathering – when food was easy to find population increased and when food was scarce it declined

– Between 8000BC & 1750 AD the earth’s population rose from 5 million to 800 million this was due to agricultural revolution – when humans began to use domesticated plants and animal

– Every country has progressed to at least stage 2


• Stage 2: High Growth– Most countries entered this stage as a result of the

Industrial Revolution – This enabled farmers to increase agricultural production &

feed the rapidly growing population– The industrial revolution led to factory jobs, better

sanitation, & personal hygiene– Europe & N. America entered stage 2 in 1800 and Africa,

Asia, & Latin America 1950’s– Medical Revolution the advances in medical technology in

Europe & N. America diffused to LDCs


• Stage 3: Moderate Growth– This happens when CBR begins to drop sharply &

the CDR also begins to decline– N. America & Europe are in this stage– Economic changes occur, people have less

children, & live in cities rather than rural areas


• Stage 4: Low Growth– This occurs when the CBR & CDR & the NIR

approaches zero– Zero Population Growth (ZPG) – Most European countries are in stage 4– Women working, using birth-control, more

income, etc…have led to less child bearing

III. Population Pyramids• Displays age & gender on a bar graph• Shows the percentage of the total population

in 5 year age groups• Shape is determined by the CBR


• Age Distribution – Dependency ration is the number of people who

are too young or too old to work– Larger the number of dependents the greater the

financial burden of those working– 0-14 & 65+ are classified as dependent – Countries in stage 2 you see a ratio of 1:1 (1

dependent for every worker)– Countries in stage 4 is 1:2 (1 dependent for every 2

workers)


• Age Distribution Cont’– The larger the number of dependents in stage 2

countries prevents poorer countries to provide services (school, hospitals)

– When there is a large population of elderly people it places a burden on governments. EX: US and Social Security, Health Care programs, etc…



– Sex Ratio is the number of males per hundred females in the population

– Poor countries generally have a lower percentage of women due to mortality during childbirth

– Younger children in poor countries are mostly male while older populations are generally higher


IV. Demographic Transition• No country remains in stage 1• Few have reached stage 4• Most countries are in stage 2 or 3• Two Big Breaks in the four stage demographic– Sudden drop in death rates – mostly due to

diffusion of medical technology– Sudden drop in birth rates

Key Issue #4: Why might the world face an overpopulation problem?

I. Malthus on Overpopulation:• Thomas Malthus (economist) argued that the

world’s rate of pop. Increase was far outrunning the development of food supply

• Said population increase would press against available resources unless the CBR decreased or disease, famine, war, or other disasters produced higher CDRs


• Neo-Malthusians:– The gap between population growth and

resources is wider than he anticipated– The population growth is outstripping a wide

variety of resources, not just food production


• Malthus’s Critics:– Some think his beliefs are unrealistically pessimistic – They believe the world’s resources are fixed not expanding– Possibilists believe humans can choose a course of action

to expand resources– Boserup & Kuznetsbelieve larger populations can stimulate

economic growth• Marxists such as Friedrich Engels said there are

enough resources but they are just not shared equally


II. Declining Birth Rates:• Malthus Theory & Reality– His theory is not supported by conditions during

the past half-century– Problems lie on distribution of wealth rather than

insufficient global production of food– Population is increasing at a slower rate than

theorized


• Reasons for Declining Birth Rates– Economic Development• Wealthier communities have more money to spend on

education & health care thus promoting lower birth rates• More educated women know their reproductive rights,

make more informed reproductive choices, & select more effective contraception• IMRs decline due to better health care

– Distribution of Contraception• LDCs are demanding a greater supply of contraceptive

devices• Use of contraceptives: ¼ Africa, ¾ Latin America, & 2/3

in Asia• Birth rates are still very high in Africa & SW Asia which

reflects the low status of women – little education, # of children reflects a woman’s status & a mans virility• Many oppose birth control due to religion or politics


III. World Health Threats:• Epidemiologic Transition is the distinctive

causes of death in each stage of demographic transition

• Epidemiologic Transition Stages 1 & 2– Black Plague (Stage 1)• Killed ½ of Europe’s pop (25 million) between 1347-

1350• Killed 13 million in China 1380


– Cholera (Stage 2)• Pandemic diseases occur over a wide geographic area

and affects a high proportion of the population• 500,000 died in 1832 in NYC• Due to poor sanitation & contaminated water supply in

poor urban areas


• Epidemiologic Transition Stages 3 & 4– Cardiovascular Disease– Cancer– Decline in infectious diseases such as Polio &

Measles


• Epidemiologic Transition Possible Stage 5– Some medical analysts think the world is moving

to a stage of reemergence of infectious & parasitic diseases

– This will cause higher CDRs


– Reasons for Stage 5• Evolution

– Resistance to antibiotics– Diseases evolve – Malaria

• Continued epidemics in poverty - TB• Improved travel – Avian flu


– AIDS• Most lethal pandemic in recent years• 95% of those infected & 99% of new cases are in LDCs• 2/3 of the world’s total HIV positive people live in sub-

Saharan Africa• Second highest rate of infection is in India


chapter two

Documents

population clusters

population densitydensity

population concentrations23

worlds populationchina

worlds populationindia

largest population cluster

study of population

agriculture key issue