environmental science and engineering-1

8/9/2019 Environmental Science and Engineering-1

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ENVIRONMENTAL SCIENCEENVIRONMENTAL SCIENCE

Environmental science is the study of nature and theEnvironmental science is the study of nature and thefacts about environment. Basically environment can be definedfacts about environment. Basically environment can be defined

as all the social, economical, physical & chemical factors thatas all the social, economical, physical & chemical factors thatsurrounds man (or) allsurrounds man (or) all abioticabiotic and biotic components aroundand biotic components aroundmanman--all living and non living things surrounds man.all living and non living things surrounds man.


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Biotic

Biotic resources are obtained from the biosphere , suchas forests and their products, animals, birds and their products, fish and other marine organisms. Mineral fuels such

as coal and petroleum are also included in this categorybecause they formed from decayed organic matter.

Abiotic

Abiotic resources include non-living things. Examplesinclude land, water, air and ores such as gold, iron, copper,

silver etc


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Scope of Environment scienceScope of Environment science

1. Studying the interrelationship between the1. Studying the interrelationship between thecomponents of environment.components of environment.2 . Carrying out impact analysis and environment Audit2 . Carrying out impact analysis and environment Audit3 . Preventing pollution from existing and new3 . Preventing pollution from existing and new

industriesindustries4. Stopping the use of biological and nuclear weapons4. Stopping the use of biological and nuclear weapons5.. Managing unpredictable disasters etc.5.. Managing unpredictable disasters etc.


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PUBLIC AWARENESSPUBLIC AWARENESS ::Environment Pollution or problems cannot be solvedEnvironment Pollution or problems cannot be solved

by mere laws. Public participation is an important aspectby mere laws. Public participation is an important aspectwhich serves the environment Protection 30which serves the environment Protection 30 --40% of 40% of public of developing country are aware of environmentpublic of developing country are aware of environmentProblems but they do not bother about it .Problems but they do not bother about it .

Need for public awarenessNeed for public awareness: :The United Nations Conference on Environment andThe United Nations Conference on Environment and

Development held at Reo de Janeiro in 199 2 (popularlyDevelopment held at Reo de Janeiro in 199 2 (popularlyknown as Earth Summit) and world summit onknown as Earth Summit) and world summit onsustainable development at Johannesburg in 2002 , havesustainable development at Johannesburg in 2002 , havehighlighted the key issues of global environmentalhighlighted the key issues of global environmentalconcern. They have attracted the attention of people.concern. They have attracted the attention of people.

Any government at its own cannot achieve the goals of Any government at its own cannot achieve the goals of clear environment until the public participate in action.clear environment until the public participate in action.Public participation is possible only when the public isPublic participation is possible only when the public isaware about the ecological and environmental issues.aware about the ecological and environmental issues.E.g. BanE.g. Ban- - the littering of polythene.the littering of polythene.


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Methods to propagate environment Awareness:Methods to propagate environment Awareness:1. Among students through education1. Among students through education introducingintroducingenvironmental studies in the curriculum.environmental studies in the curriculum.2 . Among public through mass media2 . Among public through mass media- - environmentalenvironmentalprogrammes through TV, radio etc.programmes through TV, radio etc.3 . Among decision makers, planners, leaders etc.3 . Among decision makers, planners, leaders etc.

Public awareness is needed in the areaPublic awareness is needed in the area1. Study of natural resources1. Study of natural resources- -conservation andconservation andmanagementmanagement2 . Ecology and biodiversity2 . Ecology and biodiversity conservationconservation3

. Environment Pollution and prevention3

. Environment Pollution and prevention4. Social issues related to development and4. Social issues related to development andenvironmentenvironment5. Human population and environment5. Human population and environment


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F OREST RESOURCESF OREST RESOURCESF orests are one of the most important resourcesF orests are one of the most important resources

of the world. Apart from having high commercialof the world. Apart from having high commercialimportance they provide high environmental servicesimportance they provide high environmental servicesalso. They act as a blanket on the surface of the earth.also. They act as a blanket on the surface of the earth.

Around 1/ 3 rd of world land area was found to be Around 1/ 3 rd of world land area was found to beforests. 1/5th of world forests were found in Brazil andforests. 1/5th of world forests were found in Brazil and66 --7% was in Canada and USA7% was in Canada and USA ..

USES O F F OREST:Commercial uses: F orests provide timber, fire wood,Commercial uses: F orests provide timber, fire wood,

food material, resin, gum, non edible oils, drugs,food material, resin, gum, non edible oils, drugs,medicine, rubber, fibers, bamboo and many other medicine, rubber, fibers, bamboo and many other important itemsimportant items


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Ecological uses:Ecological uses:Production of Oxygen: PhotosynthesisProduction of Oxygen: Photosynthesis earths lungsearths lungsReducing global warmingReducing global warming sink for carbon di oxidesink for carbon di oxideWild life habitatWild life habitat 7 million species in tropical forests7 million species in tropical forestsalonealoneRegulation of hydrological cycleRegulation of hydrological cycle prevent surface run off prevent surface run off

giant spongesgiant sponges 5 050 --80% moisture80% moistureSoil conservationSoil conservation hold solid particles tightly andhold solid particles tightly andprevent soil erosionprevent soil erosion wind breakswind breaksPollution moderators: absorb toxic gases and purify air Pollution moderators: absorb toxic gases and purify air

reduce noise pollutionreduce noise pollution


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OVER EXPLOITATION O F F ORESTS:OVER EXPLOITATION O F F ORESTS:

Human beings depend heavily on forests for food,Human beings depend heavily on forests for food,shelter, wood, fuel and medicine with growing civilizationshelter, wood, fuel and medicine with growing civilizationetc. shoot up resulting in large scale mining, road buildingetc. shoot up resulting in large scale mining, road buildingand clearing of forests.and clearing of forests.

Excessive use of charcoal, fuel wood, expansion of Excessive use of charcoal, fuel wood, expansion of urban, agricultural and industrial areas and overgrazingurban, agricultural and industrial areas and overgrazing

have lead to over exploitation and rapid degradation of have lead to over exploitation and rapid degradation of forests.forests.


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DE F ORESTATION:DE F ORESTATION:Deforestation is the clearance of naturally

occurring forests by logging and burning.Logging is the process in which certain trees are cut down by a machine

The total forest area of the world in 19 00 was 7 000 millionThe total forest area of the world in 19 00 was 7 000 millionhectareshectares - -19751975 2 900 million hectares2 900 million hectares 2000 2000 2300 million2300 millionhectareshectaresDeforestation rate in temperate countries are relatively moderate.Deforestation rate in temperate countries are relatively moderate.But it is alarming in tropical countries. It is estimated that in next 6 0 But it is alarming in tropical countries. It is estimated that in next 6 0 years we would lose more than 9 0% of our tropical forestyears we would lose more than 9 0% of our tropical forest

MAJOR CAUSES O F DE F ORESTATION:MAJOR CAUSES O F DE F ORESTATION:Shifting of CultivationShifting of Cultivation 300 million people300 million people 5 lakh hectares of 5 lakh hectares of forest for slash and burn cultureforest for slash and burn culturefuel requirementfuel requirement

raw materials for industrial useraw materials for industrial usedevelopmental projectsdevelopmental projectsgrowing food needsgrowing food needsovergrazingovergrazing


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What is overgrazing?What is overgrazing?It is a process of eating away theIt is a process of eating away the

forest vegetation without giving it a chance toforest vegetation without giving it a chance toregenerate.regenerate.

CONSEQUENCES O F DE F ORESTATIONCONSEQUENCES O F DE F ORESTATIONThreatens many wild life species due to destruction of Threatens many wild life species due to destruction of natural habitatnatural habitatBiodiversity is lost along with that genetic diversityBiodiversity is lost along with that genetic diversity

Hilly regions are made prone to landslidesHilly regions are made prone to landslidesSoil erosion and loss of soil fertilitySoil erosion and loss of soil fertilityHydrological cycle is affectedHydrological cycle is affected

(loss of rainfall, flood, drought etc)(loss of rainfall, flood, drought etc)


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DAMSDAMS BENE F ITS AND ENV. PROBLEMSBENE F ITS AND ENV. PROBLEMSRiver valley projects with big dams are consideredRiver valley projects with big dams are considered

to play a key role in the development of a country.to play a key role in the development of a country.India has large number of river valley projectsIndia has large number of river valley projects

These dams are regarded as symbol of nationalThese dams are regarded as symbol of nationaldevelopment.development.provides large scale employment of tribal peopleprovides large scale employment of tribal peopleand increase the std. of living of themand increase the std. of living of themcontribute for economic uplift and growthcontribute for economic uplift and growthhelp in checking floodhelp in checking floodgenerate electricitygenerate electricityreduce power and water shortagereduce power and water shortage

provide irrigation water provide irrigation water provide drinking water to remote areasprovide drinking water to remote areaspromote navigation and fishery.promote navigation and fishery.


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Environmental problemsEnvironmental problems: :The environmental problems can be atThe environmental problems can be at

upstream as well as downstream Levelupstream as well as downstream Level

Upstream problemsUpstream problemsDisplacement of tribal peopleDisplacement of tribal peopleLoss of flora and faunaLoss of flora and faunaStagnation and water logging near reservoir Stagnation and water logging near reservoir Growth of aquatic weedsGrowth of aquatic weedsMicro climatic changesMicro climatic changesBreeding of disease vectorsBreeding of disease vectors

Downstream problemsDownstream problemsWater logging and salinity due to over irrigationWater logging and salinity due to over irrigation

Micro climatic changesMicro climatic changesSalt water intrusion at river mouthSalt water intrusion at river mouthLoss of fertility due to sediment depositsLoss of fertility due to sediment depositsOut break of vector born diseases.Out break of vector born diseases.


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Timber extraction and miningTimber extraction and mining ::

The major activities in forest area areThe major activities in forest area are1.1. timber extractiontimber extraction2 .2 . miningminingThe important effects of timber extraction areThe important effects of timber extraction are

thinning of foreststhinning of forestsloss of biodiversity, particularly tree breedingloss of biodiversity, particularly tree breedingspeciesspeciessoil erosion and loss of soil fertilitysoil erosion and loss of soil fertilitymigration of tribal people from one place to another migration of tribal people from one place to another in search of new forestin search of new forestextinction of tribal people and their cultureextinction of tribal people and their culture


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Mining:Mining:Mining is a process of removing ores from areaMining is a process of removing ores from area

which is very much below the ground level. Mining iswhich is very much below the ground level. Mining isdone for the extraction of several minerals of metalsdone for the extraction of several minerals of metalslike F e, Mn, Au, Ag, etc. The minerals are especiallylike F e, Mn, Au, Ag, etc. The minerals are especiallyfound in thick forests.found in thick forests.

Mining can be carried out in two waysMining can be carried out in two ways

Surface miningSurface miningIt involves mining of mineral from the shallowIt involves mining of mineral from the shallow

deposits.deposits.Underground mining or subUnderground mining or sub- -surface miningsurface mining

It involves mining of minerals from deep deposits.It involves mining of minerals from deep deposits.The effects of under ground mining on forestThe effects of under ground mining on forest

reserves is comparatively less than that of surfacereserves is comparatively less than that of surfaceminingmining


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Environmental impacts of over extraction of mineralEnvironmental impacts of over extraction of mineralresources:resources:

Deforestation takes place due to removal of vegetation covers.The stacking of over burden and building of spoilbanks creates problems of landslidesUnder ground fire in coalmines is a hazard that isdifficult to control

Mining and ore processing normally causes air pollution and water pollutionThe acid water generated in coalmines can pose aserious problem of water pollution,Deeper excavation of ground causes lowering of

water table, which leads to drying of wells or seawater intrusionThe disposal of waste material produced after concentrations of ore create increase concentrationof heavy metals and toxic elements


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W ATER RESOURCESW ATER RESOURCES

Around 2 /3 of world surface is covered with water. Most of the Around 2 /3 of world surface is covered with water. Most of theanimals and plants have 6 0animals and plants have 6 0 --6 5% of water in their body.6 5% of water in their body.Water is used for domestic, irrigation and also industrial purposesWater is used for domestic, irrigation and also industrial purposesOut of the total available water 75 % is used for agriculture, 20% Out of the total available water 75 % is used for agriculture, 20% for industrial usage. In our country ~9 3% of water is used for for industrial usage. In our country ~9 3% of water is used for agricultural purposes.agricultural purposes.

Ground water:Ground water:9.8 6 % of fresh water is ground water and it is 3 59.8 6 % of fresh water is ground water and it is 3 5--5 0% greater than50% greater thansurface water.surface water.

Aquifer: Aquifer: The layer of soil which is permeable has the ability to storeThe layer of soil which is permeable has the ability to storewater is called an aquifer. It is generally made up of gravel, sandwater is called an aquifer. It is generally made up of gravel, sandetc.etc.

Unconfined aquifer Unconfined aquifer: it is covered by permeable layer. The: it is covered by permeable layer. Therecharge of this layer is by rainfall or snowmelt.recharge of this layer is by rainfall or snowmelt.

Confined aquifer:Confined aquifer: sandwiched between impermeable layers. Thesandwiched between impermeable layers. Therecharge is through unconfined aquifer layers.recharge is through unconfined aquifer layers.


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HYD ROLOGICAL C Y CLEHYD ROLOGICAL C Y CLE


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Over utilization of ground water:Over utilization of ground water:Over utilization of water leads to rapid depletion of Over utilization of water leads to rapid depletion of

water resources, ground subsidence, lowering of water water resources, ground subsidence, lowering of water table and water logging.table and water logging.Effects of over utilization of ground water:Effects of over utilization of ground water:

Reasons: Economic development, rapidReasons: Economic development, rapidindustrial growth and population explosion.industrial growth and population explosion.

The use of ground water and surface water The use of ground water and surface water rates which are higher than that of recharge ultimatelyrates which are higher than that of recharge ultimatelyleads toleads toWater scarcityWater scarcityWater loggingWater loggingSalinationSalinationalkalizationalkalizationwater pollution or contaminationwater pollution or contamination


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Surface water:Surface water:When evaporation and transpiration rates are lower than theWhen evaporation and transpiration rates are lower than the

rainfall, surface water body like lake, river, pond, streams etc. arerainfall, surface water body like lake, river, pond, streams etc. areformed.formed.

F lood:F lood: over flow of water, whenever the water in flow is greater than theover flow of water, whenever the water in flow is greater than thecarrying capacity of the channels flood occurs.carrying capacity of the channels flood occurs.

Causes:Heavy rainfall, snow melt, sudden release of water from dams.Heavy rainfall, snow melt, sudden release of water from dams.Prolonged down pour leading to overflowing of rivers and lakesProlonged down pour leading to overflowing of rivers and lakesReduction in carrying capacity due to obstructions or sedimentsReduction in carrying capacity due to obstructions or sedimentsetc.etc.Deforestation, overgrazing, mining increases water run off Deforestation, overgrazing, mining increases water run off Removal of dense forests from hilly regionsRemoval of dense forests from hilly regions

Effects:Effects:Submerges the flooded areaSubmerges the flooded areaLoss of soil fertility due to soil erosionLoss of soil fertility due to soil erosionExtinction of civilization at costal areaExtinction of civilization at costal area


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DroughtDroughtDrought is a period or condition of unusually dry weather Drought is a period or condition of unusually dry weather

within a geographic area where rainfall is normally present. Drought usuallywithin a geographic area where rainfall is normally present. Drought usuallyresults in a water shortage that seriously interferes with human activityresults in a water shortage that seriously interferes with human activity

Types:Types:Meteorological, Hydrological, Agricultural and SocioeconomicMeteorological, Hydrological, Agricultural and Socioeconomic

Meteorological DroughtMeteorological Drought

Meteorological drought is the amount of dryness and the duration of theMeteorological drought is the amount of dryness and the duration of thedry period. Atmospheric conditions that result in deficiencies of precipitationdry period. Atmospheric conditions that result in deficiencies of precipitationchange from area to area.change from area to area.

Agricultural DroughtAgricultural Drought

Agricultural drought mainly effects food production and farming.Agricultural drought mainly effects food production and farming.Agricultural drought and precipitation shortages bring soil water deficits,Agricultural drought and precipitation shortages bring soil water deficits,reduced ground water or reservoir levels, and so on. Deficient topsoil moisturereduced ground water or reservoir levels, and so on. Deficient topsoil moistureat planting may stop germination, leading to low plant populations.at planting may stop germination, leading to low plant populations.

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Hydrological DroughtHydrological Drought

Hydrological drought is associated with the effects of periods of Hydrological drought is associated with the effects of periods of precipitation shortages on water supply. Water in hydrologic storage systemsprecipitation shortages on water supply. Water in hydrologic storage systemssuch as reservoirs and rivers are often used for multiple purposes such assuch as reservoirs and rivers are often used for multiple purposes such asflood control, irrigation, recreation, navigation, hydropower, and wildlifeflood control, irrigation, recreation, navigation, hydropower, and wildlifehabitat. Competition for water in these storage systems escalates duringhabitat. Competition for water in these storage systems escalates duringdrought and conflicts between water users increase significantly.drought and conflicts between water users increase significantly.

Socioeconomic DroughtSocioeconomic Drought

Socioeconomic drought occurs when the demand for an economic goodSocioeconomic drought occurs when the demand for an economic goodexceeds supply as a result of a weather exceeds supply as a result of a weather- -related shortfall in water supply. Therelated shortfall in water supply. Thesupply of many economic goods, such as water, forage, food grains, fish, andsupply of many economic goods, such as water, forage, food grains, fish, andhydroelectric power, depends on weather. Due to variability of climate, water hydroelectric power, depends on weather. Due to variability of climate, water supply is sufficient in some years but not satisfactory to meet human andsupply is sufficient in some years but not satisfactory to meet human andenvironmental needs in other years.environmental needs in other years.

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Conflicts over water Conflicts over water International conflictsInternational conflicts

India and PakistanIndia and Pakistan- -Indus river Indus river Mexico and USMexico and US- - Colorado river Colorado river Iran andIran and iraqiraq-- ShattShatt--alal--arabarab river river

India and BangladeshIndia and Bangladesh- -BramhaputraBramhaputra river river National conflictsNational conflicts

Cauvery Water Cauvery Water- - Karnataka andKarnataka and tamilnadutamilnaduKrishna water Krishna water- - Karnataka andKarnataka and Andhrapradesh Andhrapradesh

SiruvaniSiruvani water water-- Tamilnadu and KarnatakaTamilnadu and Karnataka

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F lood managementF lood management ::Dams and reservoirs can be constructedDams and reservoirs can be constructedEmbankments and proper channel managementEmbankments and proper channel managementF lood way should not be encroachedF lood way should not be encroachedF orecasting or flood warningF orecasting or flood warningDecrease of run off by infiltration throughDecrease of run off by infiltration throughafforestation or rain water harvesting etc.afforestation or rain water harvesting etc.


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F ood resourcesF ood resources

PROBLEMS F ACED BY F OOD RESOURCESPROBLEMS F ACED BY F OOD RESOURCESOvergrazingOvergrazing

Land degradationLand degradationSoil erosionSoil erosionLoss of useful speciesLoss of useful species

Modern agricultureModern agricultureHigh yield variety cropsHigh yield variety cropsMicronutrients imbalanceMicronutrients imbalanceNitrate pollutionNitrate pollutionEutrophicationEutrophicationPesticide related problemsPesticide related problemsWater loggingWater logging

SalinitySalinity


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OvergrazingOvergrazing: :Grass is a good binder of soil. Overgrazing leads to loss of vegetal cover.Grass is a good binder of soil. Overgrazing leads to loss of vegetal cover.

Soil gets compacted because of excess evaporation of water. Water cannotSoil gets compacted because of excess evaporation of water. Water cannotpercolate into the soil. Roots cannot pass into the soil. Soil texture is lost,percolate into the soil. Roots cannot pass into the soil. Soil texture is lost,fertility is lost and at last leads to soil erosion.fertility is lost and at last leads to soil erosion.

Soil erosion:Soil erosion:When uncovered, waterless soil is acted upon by heavy wind and rainfallWhen uncovered, waterless soil is acted upon by heavy wind and rainfall

soil erosion results. This leads to loss of useful species and many nutrients.soil erosion results. This leads to loss of useful species and many nutrients.Overgrazing leads to replacement of thorny plants in the place of leafy, fruitOvergrazing leads to replacement of thorny plants in the place of leafy, fruitbearing plants.bearing plants.

High yield crop variety:High yield crop variety:The usage of high yield crop variety leads to monocultureThe usage of high yield crop variety leads to monoculture same type of same type of

crop is planted on large scale. In case of any pathogenic effects, due tocrop is planted on large scale. In case of any pathogenic effects, due toexactly uniform condition in the crop field, total loss is encountered.exactly uniform condition in the crop field, total loss is encountered.

Micronutrient imbalanceMicronutrient imbalance: :Excessive use of macronutrients causes micronutrients imbalance.Excessive use of macronutrients causes micronutrients imbalance.

Ex. Zinc deficiency faced in Punjab and HaryanaEx. Zinc deficiency faced in Punjab and Haryana


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LAN D RESOURCELAN D RESOURCELand is critically important national resource whichLand is critically important national resource which

supports all living organisms including plants and animals. Thesupports all living organisms including plants and animals. Thesoil profile of land determines its ability to serve sociosoil profile of land determines its ability to serve socio- -economiceconomicneeds.needs.

It has been estimated that more than 5 000 million tonesIt has been estimated that more than 5 000 million tonesof top soil is eroded annually along with 5 million tones of of top soil is eroded annually along with 5 million tones of nutrients. About 1/ 3 of this is lost in sea while the rest innutrients. About 1/ 3 of this is lost in sea while the rest inreservoirs and rivers leading to flood.reservoirs and rivers leading to flood.

About 3 8% of the area in India suffers from moderate to About 3 8% of the area in India suffers from moderate tohigh degree of water based erosion. The per capita availability of high degree of water based erosion. The per capita availability of land in the country has declined from 1. 3 7 hectare in 19 0 1 to 0 .33 land in the country has declined from 1. 3 7 hectare in 19 0 1 to 0 .33 hectare in 2000 . All these lands cannot be utilized for agriculturalhectare in 2000 . All these lands cannot be utilized for agriculturalpurpose. Some land would be required for other activities (topurpose. Some land would be required for other activities (tomaintain urban area).maintain urban area).

Effective steps have to be taken for preventing diversionEffective steps have to be taken for preventing diversionof land suitable for sustainable farming to nonof land suitable for sustainable farming to non- -farm uses.farm uses.Simultaneously, degraded lands and waste lands have to beSimultaneously, degraded lands and waste lands have to beimproved by ecological restoration. The Department of Landimproved by ecological restoration. The Department of LandResources was setup in April 1999 by ministry of RuralResources was setup in April 1999 by ministry of RuralDevelopment to act as nodal agency for land resourceDevelopment to act as nodal agency for land resourcemanagement.management.


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Land Degradation:Land Degradation:Land degradation is defined as the reduction in soilLand degradation is defined as the reduction in soil

capacity to produce in terms of quality, quantitycapacity to produce in terms of quality, quantitygoods and services. The definition is also based ongoods and services. The definition is also based onSustainability or ability to produce continuously andSustainability or ability to produce continuously andindefinitely.indefinitely.Quality of land resource that makes it sustainable or Quality of land resource that makes it sustainable or

resistant to degradationresistant to degradationCarrying capacity or the number of people andCarrying capacity or the number of people andanimals the land can normally support withoutanimals the land can normally support withoutsignificant stress.significant stress.Landscapes generally undergo degradation but areLandscapes generally undergo degradation but areusually compensated by natures inherent recoveringusually compensated by natures inherent recoveringability. Whenever degradation occur exceedingability. Whenever degradation occur exceedingnatures restorative capacity, the result will be anatures restorative capacity, the result will be adisaster.disaster.


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Man induced landslides:Man induced landslides:The hill slopes are prone to land slides, landslips,The hill slopes are prone to land slides, landslips,

rockslides etc.,. These hazardous features have reducedrockslides etc.,. These hazardous features have reducedthe overall progress of the region as they obstruct thethe overall progress of the region as they obstruct theroads, communication media and water flow. There areroads, communication media and water flow. There aretwo types of slidestwo types of slidesSlides due to natural factorsSlides due to natural factors

Slides induced by man and his activitiesSlides induced by man and his activitiesSome of the human activities that cause land slidingSome of the human activities that cause land sliding

areare1.1. Massive deforestation.Massive deforestation.2 .2 . Erratic agricultural practices.Erratic agricultural practices.3 .3 . Road building.Road building.4.4. Unscientific quarrying etc.,.Unscientific quarrying etc.,.5.5. Engineering Constructions.Engineering Constructions.


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Soil Conservation:Soil Conservation:Ways to reduce soil erosion:Ways to reduce soil erosion:TerracingTerracing: Terracing reduces soil erosion on steep: Terracing reduces soil erosion on steepslopes by concerting the land into a series of broad,slopes by concerting the land into a series of broad,level terraces. This retains water for crops at each levellevel terraces. This retains water for crops at each leveland reduces soil erosion by water run off.and reduces soil erosion by water run off.Contour F armingContour F arming: This method is adopted for gently: This method is adopted for gentlysloped land. This involves planting crops in rowssloped land. This involves planting crops in rows

across the contour of gently sloped land.across the contour of gently sloped land. Alley Cropping or Agro forestry Alley Cropping or Agro forestry: In this method crops: In this method cropsare planted together in strips or alleys between treesare planted together in strips or alleys between treesand shrubs that can provide fruits and fuel wood. Theand shrubs that can provide fruits and fuel wood. Thetrees and shrubs provide shade which reduce water trees and shrubs provide shade which reduce water loss by evaporation and preserve soil moisture.loss by evaporation and preserve soil moisture.Wind Breaks or Shelter BeltsWind Breaks or Shelter Belts: Wind breaks and shelter : Wind breaks and shelter belts or trees are established to reduce wind erosionbelts or trees are established to reduce wind erosionand also for retaining soil moistureand also for retaining soil moisture


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R enewable energyR enewable energy isis energyenergy which comes fromwhich comes fromnatural resourcesnatural resources such assuch as sunlightsunlight ,, windwind ,, rainrain ,,tidestides , and, and geothermal heatgeothermal heat , which are, which are renewablerenewable(naturally replenished)(naturally replenished)

A A nonnon- -renewable resourcerenewable resource is ais a natural resourcenatural resourcewhich cannot be produced, grown, generated, or which cannot be produced, grown, generated, or used on a scale which canused on a scale which can sustainsustain its consumptionits consumptionraterate

F ossil fuelsF ossil fuels (such as(such as coalcoal ,, petroleumpetroleum andand naturalnaturalgasgas ) and nuclear power () and nuclear power ( uraniumuranium ) are examples) are examples

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Wind power Wind power Airflows can be used to run Airflows can be used to run wind turbineswind turbines

Hydropower Hydropower Energy in water can be harnessed and used.Energy in water can be harnessed and used.

Since water is about 8 00 timesSince water is about 8 00 times denser than air denser than air even a slow flowing stream of water, or moderateeven a slow flowing stream of water, or moderateseasea swellswell , can yield considerable amounts of , can yield considerable amounts of energyenergy

Solar energySolar energy

Solar energy is the energy derived from theSolar energy is the energy derived from the sunsunthrough the form of through the form of solar radiationsolar radiation .. Solar poweredSolar poweredelectrical generation relies onelectrical generation relies on photovoltaicsphotovoltaics andandheat enginesheat engines ..

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B iofuelB iofuelLiquidLiquid biofuelbiofuel is usually either bioalcohol suchis usually either bioalcohol such

asas bioethanolbioethanol or an oil such as biodiesel.or an oil such as biodiesel.BioethanolBioethanol is anis an alcoholalcohol made bymade by fermentingfermenting thethe

sugar components of plant materials and it issugar components of plant materials and it ismade mostly from sugar and starch crops.made mostly from sugar and starch crops.

Geothermal energyGeothermal energyGeothermal energy is energy obtained byGeothermal energy is energy obtained by

tapping the heat of the earth itself, both fromtapping the heat of the earth itself, both from

kilometers deep into the Earth'skilometers deep into the Earth's crustcrust in somein someplaces of the globe or from some meters inplaces of the globe or from some meters ingeothermal heat pumpgeothermal heat pump in all the places of thein all the places of theplanetplanet

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Geothermal energyGeothermal energy

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Alternative energyAlternative energyEnergy derived from sources that do not use upEnergy derived from sources that do not use up

natural resources or harm the environment.natural resources or harm the environment.Coal as an alternative to woodCoal as an alternative to woodPetroleum as an alternative to whale oilPetroleum as an alternative to whale oilAlcohol as an alternative to fossil fuelsAlcohol as an alternative to fossil fuels

Coal gasification as an alternative to petroleum.Coal gasification as an alternative to petroleum.

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Mineral resourcesMineral resources

Mineral: Any naturally occurring chemical element or compoundMineral: Any naturally occurring chemical element or compoundthat have been formed through inorganic processes. Minerals arethat have been formed through inorganic processes. Minerals areexhaustible, nonexhaustible, non- -renewable resources found in the earths crust.renewable resources found in the earths crust.

More than 3 ,000 mineral species are known, most of which areMore than 3 ,000 mineral species are known, most of which arecharacterized by definite chemical composition, crystallinecharacterized by definite chemical composition, crystallinestructure, and physical properties.structure, and physical properties.India has large reserves of iron, manganese, lime stone, dolomite,India has large reserves of iron, manganese, lime stone, dolomite,silica, and mica but has little reserves of copper, gold, silver, leadsilica, and mica but has little reserves of copper, gold, silver, leadand phosphate.and phosphate.

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U ses of MineralsU ses of MineralsMetals are classified into various categoryMetals are classified into various category

Precious metals: gold, silver, and the platinum group metals;Precious metals: gold, silver, and the platinum group metals;Steel industry metals: iron, nickel, cobalt, titanium, vanadium,Steel industry metals: iron, nickel, cobalt, titanium, vanadium,

chromium;chromium;Base metals: copper, lead, tin, and zinc; magnesium and aluminumBase metals: copper, lead, tin, and zinc; magnesium and aluminumNuclear metals: uranium, radium, and thorium;Nuclear metals: uranium, radium, and thorium;Specialty metals: lithium, germanium, gallium, and arsenic.Specialty metals: lithium, germanium, gallium, and arsenic.Industrial minerals: quartz, salt, potash, asbestos, talc, feldspar,Industrial minerals: quartz, salt, potash, asbestos, talc, feldspar,

sulphur,phosphatessulphur,phosphates

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2 . Many minerals are essential for growth and functioning of the living2 . Many minerals are essential for growth and functioning of the livingorganisms.organisms.3 . Number of minerals used in industries, production of consumers3 . Number of minerals used in industries, production of consumers

goods, agriculture inputs,goods, agriculture inputs,hospitals and defense and research equipmentshospitals and defense and research equipments4. Construction materials include sand, gravel, aggregates, brick4. Construction materials include sand, gravel, aggregates, brickclays and limestone, cement.clays and limestone, cement.

Also included in this group are slate for roofing, and the polished Also included in this group are slate for roofing, and the polishedstones, such as limestone,stones, such as limestone,granite, travertine, and marble, collectively known as dimensiongranite, travertine, and marble, collectively known as dimensionstones.stones.5. Gemstones include diamonds, rubies, sapphires, and emeralds.5. Gemstones include diamonds, rubies, sapphires, and emeralds.

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METALS AND THEI R EXPECTED YEA R OFDEPLETIONMETALS YEA R OF DEPLETION1 Aluminum 3 12 Chromium 953 Copper 2 14 Iron 9 35 Lead 2 1

6 Manganese 4 67 Mercury 1 38 Molybdenum 3 49 Nickel 5 310 Silver 1 311 Tin 1512 Tungsten 2 813 Zinc 18


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Some Major Minerals of IndiaSome Major Minerals of IndiaCoal and lignite: West Bengal, Jharkhand, Orissa, M.P, A.PCoal and lignite: West Bengal, Jharkhand, Orissa, M.P, A.PUranium (Pitchblende or Uranite ore): Jharkhand, Andhra PradeshUranium (Pitchblende or Uranite ore): Jharkhand, Andhra Pradesh(Nellore, Nalgonda),Meghalaya, Rajasthan (Ajmer).(Nellore, Nalgonda),Meghalaya, Rajasthan (Ajmer).

Aluminum (Bauxite ore): Jharkhand, West Bengal, Maharashtra, M.P, Aluminum (Bauxite ore): Jharkhand, West Bengal, Maharashtra, M.P,Tamilnadu.Tamilnadu.Iron (hematite and magnetite ore): Jharkhand, Orissa, M.P, A.P,Iron (hematite and magnetite ore): Jharkhand, Orissa, M.P, A.P,Tamilnadu,Karnataka, Maharashtra and Goa.Tamilnadu,Karnataka, Maharashtra and Goa.Copper (Copper Pyrites): Rajasthan, Bihar, Jharkhand, Karnataka,Copper (Copper Pyrites): Rajasthan, Bihar, Jharkhand, Karnataka,M.P, West Bengal, Andhra Pradesh and Uttaranchal.M.P, West Bengal, Andhra Pradesh and Uttaranchal.

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Environmental Effects caused by mining activities are :Environmental Effects caused by mining activities are :DeDe--vegetation /Loss of biodiversityvegetation /Loss of biodiversitySubsidence of land: This is mainly associated with undergroundSubsidence of land: This is mainly associated with underground

mining. Subsidence of mining areas often results in tilting of buildings,mining. Subsidence of mining areas often results in tilting of buildings,cracks in houses, buckling of roads, bending of rail tracks and leakingcracks in houses, buckling of roads, bending of rail tracks and leakingof gas from cracked pipelines leading to serious disasters.of gas from cracked pipelines leading to serious disasters.

Groundwater Pollution:Groundwater Pollution: Sulphur Sulphur, usually present as an impurity in, usually present as an impurity inmany ores is known to get converted intomany ores is known to get converted into sulphuricsulphuric acid throughacid throughmicrobial action, thereby making the water acidic. Some heavy metalsmicrobial action, thereby making the water acidic. Some heavy metalsalso get leached into the groundwater and contaminate it posing healthalso get leached into the groundwater and contaminate it posing healthhazards.hazards.

Surface water pollution: The acid mine drainage often contaminatesSurface water pollution: The acid mine drainage often contaminatesthe nearby streams and lakes. The acidic water is detrimental to manythe nearby streams and lakes. The acidic water is detrimental to manyforms of aquatic life. Heavy metal pollution of water bodies near theforms of aquatic life. Heavy metal pollution of water bodies near themining areas is a common feature creating health hazards.mining areas is a common feature creating health hazards.

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Air pollution: In order to separate and purify the metal from other Air pollution: In order to separate and purify the metal from other impurities in the ore, smelting is done which emits enormousimpurities in the ore, smelting is done which emits enormousquantities of air pollutants damaging the vegetation nearby and hasquantities of air pollutants damaging the vegetation nearby and has

serious environmental health impacts. The suspended particulateserious environmental health impacts. The suspended particulatematter (SPM),matter (SPM), SOxSOx, soot, arsenic particles, cadmium, lead etc. shoot, soot, arsenic particles, cadmium, lead etc. shootup in the atmosphere near the smelters and the public suffers fromup in the atmosphere near the smelters and the public suffers fromseveral health problems.several health problems.

Occupational Health Hazards: Most of the miners suffer fromOccupational Health Hazards: Most of the miners suffer from

various respiratory and skin diseases due to constant exposure to thevarious respiratory and skin diseases due to constant exposure to thesuspended particulate matter and toxic substances. Miners working insuspended particulate matter and toxic substances. Miners working indifferent types of mines suffer from asbestosis, silicosis,different types of mines suffer from asbestosis, silicosis,black lung disease etc.black lung disease etc.

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environmental science and engineering-1

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