Environmental Studies Unit i 1

8/3/2019 Environmental Studies Unit i 1

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GENERAL

Planet Earth exists since 4.5 Billion Years. Life on Earth started since last 2 Billion Years. Human beings (homo sapiens) came in to existence since last 2 Million years. Civilization began since last 5000 years. Modern Science has been there since last 750 years. Nothing comes from outer space, all are constantly recycled all these years The earth is kept in a state of homeostasis, constantly changing but nothing is lost

and nothing is gained

Oxygen Cycle

1. 4.5 billion years ago, when earth was young, there was little free oxygen in theatmosphere.

2. Microbes and later plants appeared and they started exhaling oxygen as a waste by-product.

3. As oxygen levels rose, new species which had the capacity to respire- animals-appeared on earth- oxygen cycle started.

4. A dynamic balance has been maintained for the past 2 billion years- a steady oxygenlevel in the atmosphere of 21%.

NitrogenCycle

1. Atmospheric nitrogen is almost 78%, it can seldom be used directly by mostorganisms.

2. Certain bacteria found in the root nodules of leguminous plants fix this nitrogen andconvert into nitrates.

3. Fixed nitrogen is taken up by other plants or eaten up by animals (including socialanimals).

4. Through excretion from animals nitrogen enters soil and air.Carbon Cycle

1. Building block of life2. Green plants use CO2 from air for photosynthesis to produce Sugar, carbohydrate.3. Primary consumers eat these, carbon moves from plants to animals.4. Carbon returns to air as exhaled CO2.

All these are natural cycles that had been occurring on earth over billions of years.


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ENVIRONMENTAL STUDIES:

Environment is nothing but the nature composed of both biotic and abiotic factors

It includes air, water and land and its inter relationship with living organism

It dimension varies with persons it may be village, city, country etc.,

Despite physical aspects of earth (land, air and water) now it includes social, economic and political

functions.

DEFINITION:

1. Encyclopaedia of Science and Technology: A collective term describing the conditionssurrounding an organism

2. Boring: A persons environment consists of the sum total of the stimulation which hereceives from his conception until his death. Meaning Environment comprises various types

of forces such as physical, intellectual, economic, political, cultural, social, moral and

emotional.

3. Douglas and Holland: The term environment is used to describe, in the aggregate, all theexternal forces, influences and conditions, which affect the life, nature, behaviour and the

growth, development and maturity of living organisms.

TYPES OF ENVIRONMENT: Natural and Man made

A. Natural environment:

Consist of four interlocking systems namely atmosphere, lithosphere, Biosphere and hydrosphere.

These systems are in constant change either by natural or by manmade activities.

I. Atmosphere: Blanket of air and its gaseous encircling the earth including nitrogen, oxygen,carbondioxide and other gases. Extend upto 2,000 km from earths surface

(a) It sustains life on the earth.

(b) It absorbs most of the cosmic rays and major portion of electromagnetic radiation from the sun and

saves earth.

Based on the mass divided into

Troposhere: upto 10-15km weather changes occur in this zone. Highly unstable layer containswater vapour, cloud, dust and pollution.

Higher elevation in summer than in winter and higher in equator than in polar

Stratosphere: 15-50km also called a life layer where ozone is present. Mesosphere: 50-80km Thermosphere : 80-500km Exosphere: 500-2000km Magnetosphere: where influence of earths magnetic field is felt but there is no atmosphere.

II. Hydrosphere:The Hydrosphere comprises all types of water resources oceans, seas, lakes, rivers, streams,reserviour, polar icecaps, glaciers, and ground water.


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(i) Nature 97% of the earths water supply is in the oceans,

(ii) About 2% of the water resources is locked in the polar icecaps and glaciers.

(iii) Only about 1% is available as fresh surface water-rivers, lakes streams, and ground water fit to be used

for human consumption and other uses.

III. Lithosphere: the solid earth. Divided into three parts based on the composition namely crust,mantle and core:

IV. Biosphere: includes all living organisms plants, animals and micro organismsB. Man made environment: They are social, economic and political functions made by man.

Element of Environment

Environment is constituted by physical, biological and cultural elements

(1) Physical elements: Physical elements are as space, landforms, water bodies, soils, etc.,

(2) Biological elements: plants, animals, microorganisms and men

(3) Cultural elements: economic, social and political

SCOPE

Its scope is so wide that it has got relation with every science

ES is not new to us

In Tolkappiyam five fold physiographical divisions. (1) Kuruiiji or the mountain region,(2) Mullai or the forest region, (3) Marutam or the agricultural region, (4) Neithal or sandy

coastal tract and (5) Pallai or the arid desert.

In Fourth Century BC. Ashokas enforced law to protect all forms of life In Paripadal eighth century describes how Pandya constructs sluices and river channels

in Madurai along Vaigai to regulate the flood

But for the past 200 years, the industrialisation and intensive agriculture has largely degradedthe environment and its high time to revive our knowledge

Such study

1. Provide awareness about renewable and non renewable resources of a region.2. Knowledge about the ecological system and bio diversity3. Natural and man induced disasters (flood, landslide, earthquake, cyclone, tsunami etc.,)4. Knowledge on interrelationships between living and non living organisms5. Enables environmentally literate citizens (laws, acts, rules etc) to protect and improve the

earth

6. Explains the significance of forests and their products7. Gives information about water conservation, watershed management and the importance of

water


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8. How to sustainable use the resources and pass it over to our Younger generation like ourancestor given to us

Importance of environmental study:

Day by day number of environment issues are increasing and threatening the survival of mankind on

earth. The studies have become significant for the following reasons:

1. Issues like global warming and ozone depletion, acid rain, marine pollution and biodiversityare International issues

2. World population is increasing in alarming stage that too in developing countries there is aheavy pressure on the natural resources including land

3. Available natural resources are very limited4. Using modern techniques resources are over exploited5.

Unplanned exploitation leading to pollution of all types in all places

6. Polluted and degraded environment is creating lots of health hazards for all living beingsincluding human beings

7. Urbanisation and industrialisation are main reasons for pollution8. Education and training are needed to protect biodiversity and species extinction9. Its is a high time to reorient the academic system and curricula towards it10.Environment studies is a basic science which teach us to achieve sustainability and stability

within and among countries

Multidisciplinary approach

Every branch of science has their self concept and methods of study hence it is called asdiscipline.

But all the studies are towards the betterment of human society Eg. Botany plants, zoology animals etc., Multidisciplinary approach is a new method where knowledge of varied disciplines are put

together to evolve a solution for sustainable development

Science can be broadly categorised into two namely pure/theoretical and applied/practicalPure science

Eg. Physical science: physics and chemistry

Life science: Biology, Zoology

Earth science: Geology, geography

Multidisciplinary: Physical chemistry, Biochemistry, Geophysics etc.,

Environmental study is a multidisciplinary approach integrating biology, chemistry, socialscience etc.,


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According to Miller (2000) A multidisciplinary endeavour incorporating both natural andsocial sciences in the study of mans relationship with air, water and land as well as fellow

humans and other forms of life and concerned with environmental disturbances and

minimisation of the impact by means of societal changes.

Eg, decades before only engineers are consulted for constructing a dam mono or intradisciplinary approach but nowadays its economic impact, removal of forest etc., were studied

in conjunction called as interdisciplinary approach.

Merits of multidisciplinary approach

No discipline is complete by itself Man made environmental disturbances are multifaceted eg. Removal of trees in forest will directly affect the biodiversity whereas indirectly generates

chains of issues viz: increase run off leading to decrease in infiltration, increase soil erosion,

degradation of land fertility siltation in downward reservoir, reduced water holding capacity,

flooding in the environs etc.,

Hence hybridisation of disciplines is essential to solve multifaceted environmental problems.NEED FOR PUBLIC AWARENESS

1. Growing Population

Population is growing at 2.11 per cent every year, 17 million people are added each year. It puts

pressure on natural resources hence population growth has to be limited.

2. Poverty

The poverty and environmental degradation have a nexus between them. Majority of people

dependent on the nature resources for their basic needs of food, fuel shelter and fodder, Environment

degradation has adversely affected the poor who depend upon the resources

3. Agricultural Growth

High yielding varities have caused soil salinity and damage to physical structure of soil.

4. Ground water

Factors like community wastes, industrial effluents and chemical fertilizers and pesticides have

polluted our surface and groundwater hence keeping water bodies clean is essential.

5. Forests

Forests serve catchments for the rivers for developmental activities agriculture, irrigation etc

shrinking (Narmada, Bhagirathi) conserve them.

6. Degradation of Land

66 per cent of land is degraded by using fertilizers and pesticides, erosion, water scarcity etc.,

7. Genetic Diversity


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At present most wild genetic stocks have been disappearing from nature. The protected areas network

like sanctuaries, national parks, biosphere reserves are isolating populations. So, they are decreasing

changes of one group breeding with another.

8. Urbanisation

Nearly 27 per cent Indians live in urban areas. Urbanisation and industrialisation has given birth to a

great number of environmental problem that need urgent attention. Over 30 percent of urban Indians

live in slums. Out of Indias 3,245 towns and cities, only 21 have partial or full sewerage and

treatment facilities. Hence, coping with rapid urbanization is a major challenge.

9. Air and water Population

Majority of our industrial plants are using outdated technologies devoid of any provision of treating

their wastes. Acts are enforced but their implement needs public awareness.

10. Reorientation of Institutions

Change should be brought in education, in attitudes, in administrative procedures and in institutions.

Because it affects way people view technology resources and development.

Individuals are responsible for all environmental problems Hence it is essential to create awareness among public to know about the sources of pollution,

how to minimise them and finally eradicate them so that save the earth to future generation.

CREATING PUBLIC AWARENESS

Awareness is a continuous process in which individuals has to be triggered towardssustainable development

Individuals of schools, colleges, industries, community centres etc., should realise theimportance of day to day environmental issues

Individuals should practice environmental conservation and create awareness among familymembers

Expose the problems by writing in dailies and forums Again and again issues should be discussed until the problems are totally eliminated Research, workshops and conferences should be conducted

GOVERNMENT AND NON-GOVERNMENT ORGANISATIONS INVOLVED:

World wide fund for nature, New Delhi (WWF-I) Centre for science and Environment, New Delhi (CSE) Centre for Environment Education (CEE), Ahmedabad Environment Education centre, Chennai Wildlife institute of India (WII) Dehradun Botanical Survey of India(BSI) Calcutta Zoological Survey of India (ZSI) etc.,


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NATURAL RESOURCES

A resource is everything we get from environment for our needs

The economy of a country is based on its resources

Resources: Anything from living and non-living environment to satisfy human needs

Worlds population is heaping 2% per year; demand for resources is of several fold

In 40-50 years maximum resources could be exhausted - to over come

New technologies to improve the efficiency: 7 times more electric power from 1 ton of coal Recycling: matter resources copper, lead, tin etc, Replacement: wood, coal, oil replaced by solar, wind and wave energy

Types of Natural Resources

(I) Renewable resources(II)Non renewable resources can be recycled(III) Non renewable resources cannot be recycled1. Renewable resources: replenished by natural cycle

Eg: oxygen in air photosynthesis

Water hydrological cycle

Biological products re growth

However if utilization rate exceeds replacement rate then availability will decrease called as

Environmental Degradation

2.

Non Renewable resources: (can be recycled)All non energy minerals metallic (Cu,Ag, Al, etc.,) or non metallic (Si, K etc.,) Eg. Glass (Si)

can be reused

3. Non Renewable resources: (cannot be recycled)Fossil fuels once converted into to energy then exhausted cannot be recycled for replenish

will take millions of years

In order to avoid environmental degradation - Sustainable yield should be followed if 50

animals in year gives 10 offspring 10 is safe yield


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FOREST RESOURCES

Most important renewable NR

IMPORTANCE OF FOREST

I. PROTECTIVE functionWatershed protection:

Reduce the rate of run-off

Prolonged gradual run-off - prevent flood and drought.

Increase groundwater potential (2.5mha forest can store 2.5 time more water than bakhra

dam)

Atmospheric regulation:

Absorption of solar heat during evapo-transpiration.

Maintaining the local and global climatic conditions. Absorbing atmospheric CO2 - acts as sinks - regulates green house effect

Erosion control:

Holding soil by roots - preventing erosion

Erosion 0.3 tones/yr Due to shifting cultivation 2.8 tones/yr Removal/forest blank 53.4 tones /yr

Land bank:

Holding high nutrient soilII. PRODUCTIVE function

Food - gathering plants, fishing, hunting from the forest. Fodder - for cattle. Fuel wood and charcoal for cooking, heating. Timber household articles and construction. Fibre - weaving of baskets, ropes, nets, string, etc. Apiculture - bees for honey and also pollination. Medicinal plants

III.ACCESSORY FUNCTIONS Recreation Aesthetics Habitat for diverse wild life.

FOREST TYPES

Precipitation and Temperature Vs Vegetation

Low moisture and low temperature : Tundra forest


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High moisture and Freezing temperature: Deciduous or Coniferous

High rainfall and high temperature : Tropical rain forest

Moderate rainfall : Grassland / savannas

Dry climate : Desert

Forest resource of India

Monitored by Forest Survey of India Classified using remote sensing on the basis of crown density dense forest (>40%), open

forest (10-40), Scrub forest (


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Effects of deforestation on Tropical forest

By 2042 50% of species will extinct 2000 species of herbal plants in India alone 45,000 species of flowering plants During ice age tropical forests serve as house of many species 25% of drug ingredients derived from forest plants including cancer The rosy periwinkle flower is only found in Madagascar. It is used to treat cancer but this

plant could be lost if the rainforests are destroyed.

Transgenic biotechnology genetically revived form wild varieties (during seeds affected bydisease)

Drugs from skins of wild frogs acts as painkiller hundred times more efficient than morphineEffects of deforestation on tribal people

5000 tribal cultures are being vanished owing to economic development

CONSEQUENCE OF DEFORESTATION

Economic loss : Future revenue and employment from timber and other resources will ruin Loss of biodiversity: Extinction of thousands spices of plants and animals Reduction in stream flow Perennial rivers would become seasonal leading to drought and flooding Reduces the stream water quality Accelerates siltation in downstream dam and tanks Destruction of tribal lifestyle Increases the rate of global warming: increase the amount of carbon dioxide resulting in

melting of ice, extreme flood and drought,

Change in global weather pattern and climate Accelerated soil erosion Degradation of soil: expose soil to sun and rain increase its compaction reduce organic

matter leaching out of nutrients increase aluminium toxicity

Induce mass movements and landslides - roots of tree hold the materials along the slope Increase runoff flooding Breaks water and nutrient cycle


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DEFORESTATION CASE STUDIES

The Rainforest of Amazon Basin

One thirds of worlds tree grown here

5300 km long Trans-Amazon Highway timber extraction- exploitation of minerals like iron

manganese, gold etc.,

Number of hydel-power projects

The rainforest of Malaysia

During colonial period destroyed for rubber plantation (worlds leading exporter) decline in

market after artificial rubber - after 1970 shifted to oil palm tree plantation (leading exporter)

swan wood export (world third)

Timber extraction, Mining and Dams its effect on forest and tribal people:

Forest degradation in India

India comprises (6,37,297 sq.km) 1.8% of worlds forest cover (seventh largest country, second

populous)

Contributes 1.7 % of GDP of the country

India is poorest as per capita forest land is concerned 0.08 ha world average 0.64 ha

Lost 3.4 M ha between 1950-72 due to industrialization dam and road construction

1% of land becoming barren every year due to deforestation

In Himalayas 3-4% of decrease in rainfall

A person needs oxygen produced by 16 big tree. In India 36 people share a single tree. In cities like

Patna over 2500 people share a single tree, in Calcutta 15,000 people do the same.

Sustainable forest management

Government Initiatives

Chimpko movement

Wildlife protection act (1972)

Forest Conservation act (1980)

Creation of Ministry of Environment and Forest (1988)

Last fifty nine years 31 M ha of land planted


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Conservation of Reserve forest: National parks,, sanctuaries, biosphere reserves etc.

Public initiatives:

Planting of private and community land social forestry/agro forestry/farm forestry - initiated

1980

17 M ha eucalyptus, teak, acacia etc., permitted by government

Joint efforts :

Under JMF (Joint Forest Management Programme, 1990) involving government and local

communities 26 states 10.25 M ha

WATER RESOURCES

74% of the Earths surface is water 97% of the Earths volume of water is in the saline oceans 2.2% in the permanent icecap Only 0.02% is in freshwater streams, river, lakes, reservoirs Remaining water is in:

- underground aquifers (0.6%),

- the atmosphere in the form of water vapor (0.001%)

Hydrologic cycle


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The movement of water particles from sea atmosphere land and back to sea iscalled as Hydrologic cycle

The energy from solar system and gravitational force which governs the movement Ocean is the major source of water Solar energy converts water in to vapour and forms as clouds in the atmosphere Condensation leads to precipitation on land surface Part forms surface run off flow and part gets recharged into the sub surface Finally drains into the ocean

Water on the land can be classified into two categories

I. SURFACE WATER:River, Stream, Lakes, Ponds, Ice etc.,

II. SUB SURFACE:Beneath the ground

ORIGIN OF GROUNDWATER

Meteoric water: Derived from Precipitation Connate water: Entrapped in rocks during sedimentation Magmatic water: During the condensation of lava Metamorphic water : Formed during metamorphic activity

VERTICAL DISTRIBUTION OF WATER

ZONE OF AERATION: Filled mostly with air and water ZONE OF SATURATION: Filled completely with subsurface water Water Table: Upper surface of saturated zone

POROSITY: Ability of rock to store water

Total volume of voids in sediments / Volume of sediment Sedimentary rocks: Grain size and packing Metamorphic rocks: Foliation and lineation Secondary porosity: Joints, Faults etc.,

PERMEABILITY: Ability of rock to transmit water

Based on the interconnected pore spaces


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Aquifer: Rocks with both porosity and permeability Aquifuge: Rocks with no porosity and permeability (Igneous rock) Aquiclude: High porous but no permeability (Igneous Clay, Shale etc.,) Aquitard: with considerable interconnected fractures Eg. Clay lenses interbeded with

sand

TYPES OF AQUIFER:

Unconfined: Underlained by imperious layer upper surface is water table Eg. Sandbody underlained by hard rock

Confined: Under and Overlaid by imperious layer results in artesian well Semiconfined: If the bounding layers are not completely impermeable

INDIAN WATER RESOURCES

India has 2% of worlds land, 4% of freshwater, 16% of population, and 10% of itscattle.

India receives 4000 B cu.m / year 41% lost by evaporation 40% lost by run off (stream flow) 10% retained as soil moisture 9% gets into groundwater

Out of 40% stream flow (1869 B cu.m) 8% used for irrigation 2% for domestic use 4% for industry and 12% for electricity generation The overall usable water is 1122 B.cu.m Hence per capita available water resource is 1122 cu.m By 2025 due to various problems the per capita availability will be 748 cu.m If countrys per capita is less than 1700 cu.m water stressed country


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Water Demand

MAIN RIVERS IN INDIA

1. Himalayan water system: Indus, Ganges Brahmaputra, Chinab, Jhelum, Ravi andBeas

2. Deccan plateau water system: Narmada, Tapti, Mahanadi, Godavari, Krishna, Periyar3. Others inland water systems4. Coastal water systems

RIVER BASIN STATISTICS

Himalayan Rivers Water: 300 utilizable, 1200 BCM available. Himalayan large dams presently store 80 BCM. New dams under consideration could

store 90 BCM.

Peninsular Rivers Water: 400 utilizable, 700 BCM available. Peninsular large dams presently store 160 BCM. New dams under consideration

could store 45 BCM.

In all, large dams presently store 240 BCM. New dams under consideration couldstore 135 BCM. Total storage thus could be 375 BCM only.

WATER RESOURCE IN TAMIL NADU

Total Geographical Area : 13.01 M Ha. (4.0% of India) Water Resources : 4.49 M.Ha.m (3.0% of India) Population as on 2001 : 62.11 M (6.4% of India) Districts : 31 Taluks : 206 Blocks (Revenue) : 385 Villages : 17,273 River Basins : 17


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Sl.No.

Year ofAssessment

No. ofDistricts

TotalNo. ofBlocks

Categorization of BlocksDark

(85-100%)Grey

(65-85%)White(65%)

1 1987 19 378 41 86 251

2 1992 22 384 89 86 209

Over-Exploited(>100%)

Critical(90%-100%)

Semi-Critical(70%-90%)

Safe(


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MANS WATER REQUIREMENT, USE AND OVEREXPLOITATION

REQUIREMENT SECTORS

Irrigation (70%), Industry(5.7%), Livestock management and domestic (4.3%), power

generation(6.2%), fisheries, navigation and recreational activities.

CONSERVATION

Reduce over exploitation

More water used that actual need returned as surface flow in impure stage reduceover consumption

Efficient Distribution system

Surplus water can be diverted to deficit areas - Interlinking of rivers and Interwatershed transfer

Efficient Use of Water

Appropriate techniques for optimizing water use efficiency Scientific water management and farm practices Measures to minimize water loss lining canal crop duration incentives to change

from wet to dry crops integrated source use well/tank/others

Reduction of pollution and recycling of water

Pollution spoils huge quantities of surface water Polluted water treatment safely discharged into aquatic systems

DESALINATION METHODS

Distillation:

By boiling, the fresh water is evaporated and salt is retained, the evaporated water isthen condensed

About three-fourths of worlds production uses this method. The more energyrequirement makes this process expensive.

Freezing:

Ice crystals exclude salts as they form and the ice can be melted for use


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Reverse Osmosis:

In this process sea water is forced against a semi permeable membrane at high pressure Fresh water seeps through membranes pores while salt stay behind About quarter of fresh water is produced in this way It requires less energy than other two methods but the membranes are fragile and costly In Middle East, West Africa, Peru, Floridam Texas and California more than 1,500

desalination plants are operating at present and producing about 13.3 billion liters (3.5

billion gallons) of water per day.

The largest desalination plant in Saudi Arabia produces 114 million liters (30 milliongallon) daily

Improving surface storage capacity

Around the world 27,000 c.km water discharged into ocean Desilting tanks, dams improving storage capacity Resurrecting supply canals and rivers Construction of new dams and embankments

Improving subsurface storage capacity

10-15% of total precipitation enters into subsurface Artificial and natural recharge structures (check dam, percolation ponds, recharge

wells, subsurface dykes etc,)

Augmentation of existing supplies of fresh water

Desalination of sea water and Artificial rain 20-30% of atmospheric moisture precipitates rain and snow - silver

iodide, sodium chloride, dry ice (solid CO2)

Rain Water Harvesting

Rain Water Harvesting RWH- process of collecting, conveying & storing water from rainfall in an area

for beneficial use

1.Provides self-sufficiency to water supply

2.Reduces the cost for pumping of ground water

3.Provides high quality water, soft and low in minerals


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4.Improves the quality of ground water through dilution when recharged

5.Reduces soil erosion & flooding in urban areas

6.The rooftop rain water harvesting is less expensive & easy to construct, operate and

maintain

7. In desert, RWH is the only relief

8. In saline or coastal areas & Islands, rain water provides good quality water

FLOOD

Flood is a body of water which rises to overflow land which is not normally

submerged (Ward 1978)

Types of Floods

Flash Floods:

Associated with storms of short duration

Single Event Flood:

Due to heavy rain ( 2 3 days) over a drainage basin

Multiple Event Flood:

Due to successive Heavy rainfall

Seasonal Flood:

North India Summer Monsoon (June to September)

South India Winter Monsoon ( October to December)

Natural Causes Of Floods

Excess Rainfall High Coastal waves - tides / storm surge / tsunamis Tropical disturbances hurricane / thunder storm / cyclone Volcanic eruption Snow melt Avalanche Dam / levee failure

Man Made Causes of Floods

Check in rivers, tanks and irrigation channels Siltation and chocking of reservoirs, river beds and tanks


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Destruction of forest & vegetal cover Unauthorized cultivation along irrigation channels Unauthorized encroachments of flood plains, irrigation channels, etc., leads to obstruction

to free flow of water.

Mitigation Measures

Reservoirs: Can moderate the intensity and timing of the incoming flood. Embankments : confine the flood flows and prevent spilling, thereby reducing the damage Sea walls: Stopping the sea waves from eroding the valuable coastal beaches and land. Channel/drainage improvement: By desilting, dredging, lining, etc., increase the discharge

downstream

Diversion of flood waters: Taking a part of the flood discharge from one basin to another Watershed Management: Developing and conserving the vegetative and soil cover and also

structural works like check-dams, diversion channels, etc.,

Modify susceptibility to flooding by: Flood plain regulationsDROUGHT

Definition: An extended period of deficient rainfall a season, a year or several years

The drought of 1987 was one of the worst in the century. The overall deficiency in rainfall was 19%

as compared to 26% in 1918 and 25% in 1972 being worst years.

Consequence of drought;

Desertification: the process by which an area becomes more barren, less capable of retaining

vegetation and progress towards becoming desert.

Causes: climate failure, abusive land use practice- removal of forest, over grazing

Famine: Food shortage due to climate, environment and socioeconomic reason

Mitigation: involves three phases

1. Preparedness phase: changing land use pattern2. Prevention phase; watershed management practice3. Relief phase: restore families


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DAMS

Water storage is essential because rainfall varies with maximum 10000mm inCherapunji in Assam and minimum 100 mm in western Rajasthan

Over 75% rainfall received in monsoon between June October India has 4291 dams 9% of world dams Out of 178million hectare meter available surface water 16mham is stored in dams

Environmental impacts of dams

Impacts will be both within and around the dam

Downstream effects caused by alteration in hydraulic gradient Changes in micro climate, loss of vegetal cover, soil erosion, induced seismicity etc., Socio economic problems Deforestation by laying roads Landslides due to blasting etc., Dam failure will cause severe loss Siltation loss in dam capacity flooding reduction in fertile soil supply in

downstream fisheries induced coastal erosion

Water logging and salinity: rising water table in dam increase water level incommand area water logging problem increased moisture even small rains cause

flood

Tehri dam: Tehri district; Rivers Bhagirathi, Jilganga; height of dam: 260.5m; submergence: 112

villages, Tehri town, 36,000 hec forest; 1600 hec agricultural land

Sardar Sarovar: Bharuch district of Gujarat : 245 villages will be submerged in MP, maharastra and

Gujarat, 75,000 people will be evicted -

Reservoir induced seismicity: Koyna reservoir caused seismicity during 1967.

RIVER WATER DISPUTES: Dispute around the world date back to 5000 years

Water resources as reservoir, dam and canal system acted as targets during time of war

International dispute: Ganga India, Bangladesh and Nepal ; Bhramaputra: India and Bangladesh

Local disputes: Narmada- Maharashtra, Gujarat, Rajasthan and MP; Krishna- AP,Mh,TN and

Karnataka; Cauvery- Karnataka, TN and Kerala

Water Pollution:

90% of surface water in India polluted polluting industries sugar, distilleries, textile, tanneries

etc.,


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MINERAL RESOURCES

GENERAL:

A naturally occurring, inorganic, crystalline solid that has a definite chemical compositionand possesses characteristic physical properties

A countrys economy depends on its mineral wealth it posses Petroleum provides gas and oil for fuel, Limestone for construction, Potash mines contribute

to fertilizer, coal to energy production, precious metals and gems for jewelry etc.,

Industrialisation and population explosion forced to extract more and more resources Unscientific exploitation practised over decades significantly degraded the environment

MINERAL DEPOSIT: Any accumulation of useful minerals which are originally in a diffused state.

Metallic Mineral Deposits: Concentration of metals which are originally in a diffused state.

Ore Mineral: From which one or more minerals can be extracted at profit. Eg. Galena - mined for

Lead

A single metal can be extracted from a number of ore minerals Eg: Copper fromChalcopyrite, Chalcocite, Cuprite, Malachite etc.,

A single ore mineral may contain more than one mineral Eg. Mineral Stannite containsCopper and Tin.

Non Metallic Mineral Deposits: The materials of non-metallic deposits consist of solids, liquids and

gases. The term ore is not used to refer such deposits. They are referred by the substance itself Eg:

Mica, Petroleum, Asbestos etc.

DISTRIBUTION :

Origin and occurrence of mineral deposits are restricted to certain geological periods and

geographical area

The geological periods are characterized by formation large number of mineral deposits is termed as

Metallogenetic Epochs

Eg. Most of the Iron ores in India are formed during Precambrian time


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Chief Metallogenetic Epochs in India

1. Precambrian2. Late Palaeozoic3. Late Mesozoic to Early Tertiary

Precambrian Epoch (3500 1500 million years before)

It is an important epoch around the world with large number of mineral deposits

In India this epoch contains minerals like

Iron ore in Bihar, Orissa, M.P, Maharashtra, Karnataka, Goa etc., Chromite ., , Gold in Karnataka, Tamil Nadu, Andhra Pradesh Copper in Rajasthan, Bihar, M.P etc., Lead and Zinc In Rajasthan, Orissa etc.,

Manganese, Sillimanite, Gypsum, Kyanite, Gemstones etc

Permo-Carboniferous (Late Palaeozoic) Epoch (400 250 M.Y)

Hercynian movement introduced marked mountain building activity and initiation of sedimentary

era on the surface of the Earth

In India this epoch contains richest coal deposits of Lower Gondwana period inBihar, M.P, A.P

Later intrusion of dolerities, basalts, ultra basics gives rise to Fire clay, Iron stone,Ochre etc deposits

Late Mosozoic To Early Tertiary Epoch (150-40 M.Y)

Deccan trap formation

Semi precious stones like rock crystal, amethyst, agate, onyx, chalcedony and alsorarely copper mineralisation

Igneous activity in extra peninsular (northern India) results in

Magnetite, Chromite, Asbestos etc in Manipur, Nagaland, Andamans, LadakhMetallogenic Province

The area dominant by a particular type of mineral is called as Metallogenic province


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Eg. Gold province, Copper province, Iron ore province, Lead and Zzinc province etc.,

1. Gold province of Karnataka Andhra Pradesh - Tamil Nadu (Hutti Kolar Anantpur Godag Wynad Gold province)

2. Copper province of Singhbhum3. Copper province of Khetri Pur Banera Bhinder4. Lead and Zinc province of Hesatu Belbathan5. Iron ore province of Singhbhum Keonjhar Sundergarh Mayurbhanj6. Iron ore province of Durg bastar Chanda - Ratnagiri7. Iron ore province of Karnataka and Goa8. Manganese province of Balghat Bhandara Nagpur

USES

I. Metallic mineralsIron: ore mineral Hematite and magnetite

Basis for modern industrialization huge variety ofproducts from frying pan to locomotives

Copper: important ore chalcopyrite

Important industrial mineral Manufacturing electrical wires and equipments,

brass etc.,

Aluminium : Bauxite important ore

Manufacturing airplanes, electrical cable, soft drinkcans etc.,

Lead: ore Galena

Battery manufacturingZinc: ore Sphalerite

Used for galvanizing and manufacture of brass and other alloysSilver: Found as native metal and in sulphide ores and it is common by product of lead and copper

Manufacture of coins, tableware, jewellery, photographic films etc.,Gold: native element


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Jewellery, dentistry, decoration etc.,Other metallic minerals: chromium, nickel, cobalt, manganese, molybdenum, tungsten and

vanadium important in steel industries.

II. Non metallic minerals:Gemstones: includes precious stone diamond, ruby, emerald, sapphire and semi precious stones -

beryl, garnet, topaz, zircon etc

Generally used for jewelleryAsbestos: fibrous variety of mineral called serpentine

Used for Fireproof fabrics, insulation, brake lining etc.,Barite: high specific gravity used in drilling for sealing leakages

Graphite: lubricants, batteries, pencil etc.,

Others: phosphate, nitrate and potassium minerals used as fertilizers.

III. Mineral fuels: Coal, Natural gas and PetroleumEXPLOITATION OF MINERAL RESOURCES:

Opencast mining Underground mining Placer mining

MARINE MINERAL RESOURCES

Minerals of continental margin:

Minerals mined from near shore, beach and continental margin, they are partial derived

from erosion of land areas and from marine itself.

Sand And Gravel

The sand and gravel found along beaches and near-shore sediments are locally extractedfor use in construction

Placer Deposits

Concentration of economically valuable dense minerals along beach and near shoreregions by wave and current processes are called as placer deposits.


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Formed by the deposition of dense particles at a site where water velocity remainsbelow that required to transport them further.

The most important of these deposits contain gold, platinum, diamonds, etc., Today, much of the world's tin and many of the gem diamonds are recovered by

dredging near-shore ocean sediments.

Gold has been recovered in the past from such deposits, most notably in Nome,Alaska.

Diamond is found in offshore gravel in Australia and Africa and mined by De Beercompany using four offshore mining vessels mined 450,000 carats of diamond from

Africa.

Heavy Mineral Sands

Heavy mineral sands are placer deposits formed most usually in beach environments by

concentration due to the specific gravity of the mineral grains.

They contain zirconium, titanium, thorium, tungsten, rare earth elements, industrial minerals like

diamond, sapphire, garnet, and occasionally precious metals or gemstones

Ooids

Calcium carbonate occurs as sand size spherical grains called as Ooids in the shallowwarm waters of low latitudes. Eg. Bhama of east Florida having extensive ooids

accumulation

Phosphorite

Phosphorite occurs along continental shelf especially near the outer edge of theshelf.

Generally concentrated in areas of upwelling where phosphate rich waters rise nearthe surface

Due to warming, the pH increases resulting in precipitation of phosphate minerals Also formed due to decay of remains of marine organism

DEEP SEA MINERALS

Manganese Nodules

The best known deposits of deep sea are manganese nodules This iron and manganese oxide occurs as spheres upto 20 cm in diameter


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They occur in ocean basins at about 4 km below sea level covering millions of squarekilometer or 25% of deep sea floor.

They grow at an average rate of 1 to 10 millimeters per million years one of theslowest chemical reaction in nature

Poly Metallic Nodules

Valuable trace elements from sea water can be precipitated directly onto the seabed,forming nodules that are enriched with cobalt, nickel, iron, manganese and copper.

MINERALS FROM OCEAN BOTTOM

Bottom of ocean contains resources like petroleum, sulfur, coal, iron etc.,

Petroleum And Natural Gas

First offshore oil field was discovered in Louisiania in 1938 Now offshore exploration accounts 35% of crude oil and 26% of natural gas total

production

Formation

Planktonic organisms or soft bodied benthic marine animals get accumulated in quietbasins where oxygen was low

The anaerobic bacteria convert the tissues into to simpler insoluble organic compounds They were buried by turbidity currents and later covered by sediments At high temperature and pressure, 2 kms beneath ocean floor, slow cooking will take

places for millions of years and finally they were converted into oil

If the organic material is cooked too long or at too high temperature, it will turn intomethane, the dominant component of natural gas.

ENVIRONMENTAL ISSUES

In order to coup the needs, mining activities has substantially increased in last three decadeswith 42% increase in number of mines, Coal by four fold, Iron ore and Copper 11 times,

Bauxite 33 times, Limestone 16 times etc.,

Overexploitation leads to plethora of environmental issuesWater pollution: sliding of loose materials from dumps, tailings, overburden etc., into the adjoining

water courses

Mine drainage and coal washing operations


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Air pollution:

Gaseous pollution: Release of toxic gases into atmosphere (sulphur dioxide, nitrogen oxides,carbon monoxide and hydrocarbon)

Suspended particle: Dust pollution (silica, fluoride, asbestos and metallic dust)Noise pollution: blasting and operation of heavy machineries

Land degradation:

Large scale removal of overburden and their dumping and Disposal of wasteLandslip/landside/soil erosion:

Opencast mining in hilly areasOthers: Deforestation, Disruption of water regime, miners health, economic devaluation of land etc.,

Case studies:

Kudremukh Iron ore mining:

Chickmagalur district of Karnataka opencast mining started during 1977 Decrease in forest area Degradation of Kachiga and Kudremukh settlements Water pollution of Bhandra river

The Dehra Dun Mussoorie mine belt:

Mining activity started in 1911 area is rich in forest and water resource Deforestation and degradation of forest Reduction of agriculture land Shallowing of river

Increasing landslips and slides


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FOOD RESOURCES

Food is a nutritive substance consumed by living beings for their growth and work. Amongst 105developing countries, 64 are in deficit with respect to their population Every day 250,000 babies are added to population additional food, cloth and shelter By 2025 worlds population is estimated to be 8.5 billion so in another 15 years we

must produce what we have during the past 10,000 years

On the earth 8000 edible species are in existence but only 30 types were effectivelyutilized

Wheat, rice, corn and potato are most commonly used 16th October World Food Day

WORLD FOOD PROBLEM

Food problem involves complex interactions among production, population explosion,poverty, economic and political systems

Global food production (quantity) increased substantially over past two decades But achieved through extensive utilization of water, soil resource, fertilizer and

pesticides

Quality of food grains vary between nations

Storage of food grains and others (vegetables fruits meat etc.) differ amongst hot andcold countries

Distribution of food grains amongst poverty people Varying subsides for agriculture amongst countries Food production increased 140% between 1950 and 1987 Appreciable quantity of food gets rot and consumed by pests If all food produced in world shared then per capita food will be three times more than

need

Production is not distributed equally amongst people in the world It is also not equally distributed even between family embers male as working

member consume more food than female

AGRICULTURAL PRODUCTION

Two major agriculture systems was followed to raise crop and livestock


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1 Traditional Agriculture

Traditional Subsistence agriculture: crops and livestocks are produced for their survival

through human labour and draft animals

Traditional Intensive agriculture: surplus production chiefly aimed at selling including their

family need through excess man power, fertilizer and water

2. Industrialized agriculture; practised in developed countries by using fossil fuel energy,

water, commercial fertilizers and pesticides to produce huge quantities through monoculture

(single crop) and livestock

Green revolution: Increased yield per unit area is called as green revolution

Ist green revolution during 1950 achieved through Monoculture or high yielding varieties Lavishing fertilisers, pesticides and water Intensity and frequency of cropping

2nd Green revolution during 1967 Through using specially breed wheat and rice

Production increased two to five fold than traditional method A third green revolution is envisaged through biotechnology

LIVESTOCK PRODUCTION

Domesticated animals: cattle, horses, oxen, sheep, chickens and pigs Provides food, fertilizer, fuel, cloth and transportation Increased to sustain increasing population leads to overgrazing

INDIAN AGRICULTURE PERFORMANCE

1998-99 was record of 20.8 million tones 1950-51 I st green revolution 1970 second green revolution M.S Swaminathan father of Indian green revolution Landuse: 99.3 m.ha in 1950 to 127.5 m.ha in 1991 - Increase through deforestation


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Fertilizer consumption: last three decades nitrogen, phosphorous and potassiumincreased to 9.5% annually fourth largest consumer of fertilizers in the world.

Pesticide consumption:27 thousand tonnes in 1971 to 82 thousand tonnes in 1991.

Irrigation: agricultural land increased from 32% in 1970 to 43% in 1990 throughextraction of more groundwater in 2025 85 million hectare meter of water will be in

demand for agricultural purpose.

CHANGES CAUSED BY OVERGRAZING

Domestication of crops started 10,000 years ago Agriculture was subsistence in early stage and later commercialised due to increase in

need

Invention of new breed, fertilizers and pesticides leads to environmental problems Food production per person dropped 21% between 1960 and 1987- in Africa due to

drought, deforestation, overgrazing, soil erosion etc.,

Best lands were used for commercial crops (Coffee and Cacao) export Inland war and increasing population Increased livestock and poor agriculture practice decline in soil quality and

overgrazing of marginal lands

Anthropogenic problems : Soil erosion in North America, Soil acidification inEurope, Deforstation and desertification in Asia, Africa and Latin America and waste

and pollution of water everywhere

In forthcoming decades global warming may flood coastal areasEnvironmental degradation

Application of huge quantities of fertilizers, pesticides and insecticides Increase irrigational facility water logging Conversion of marginal land and grass land into to agricultural land Deforestation soil erosion loss of soil fertility Replacement of forest by plantation changes its ecosystem Shifting cultivation consumed millions of square kilometre of natural forest Monoculture leading to ecological imbalance


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Fertilizer and pesticide problems

Synthetic Organic Compounds

Includes pesticides, plastics, solvents etc.,

DDT - chlorinated hydrocarbon pesticide

The best known of these pollutants is DDT - Pesticide used during 1950s -1960s

Causes reduction in calcium carbonate of organism tissues leads to eggs with vary

thin shells easily breakable threatening population of birds.


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PCBs: Polychlorinated biphenyls

Fluid used to insulate electrical devices and to strengthen concrete and wood

Declining the fertility and immune system

Poly-aromatic hydrocarbons (PAHs)

Typically come from oil pollution and burning wood and coal. These PAHs are

responsible for causing genetic chromosomal aberrations

Bio Accumulation:

If animal receives small quantities of persistent pesticide along with its food, the insoluble

matters get accumulated in fatty tissue prolonged consumption will increase the

concentration in animal. This process of accumulating higher and higher amounts of material

within the cell of an animal is called as bioaccumulation.

Bio-Amplification:

When a carnivore eats the affected animal then toxins are concentrated within the carnivore

continued consumption leads to disease or death. This transformation of toxins from lower to

higher order is called as bio-amplification.


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Eg. If an aquatic system receives small amount of DDT in due course the concentration of

DDT in aquatic organism will be 250 times more than what is there in aquatic system. If

these were eaten by small fishes and then by large fishes the net concentration will be 2000

times more if it is consumed by birds or humans the effect will be ....

Environmental limits for increasing food production:

Continuing input of fertilizer, water and pesticides and its induced crop yield will obsolete at

one stage. Now the increase in productivity has come down from 2.3% in 1950 to 1% in

1984.

Loss of genetic diversity limit crop yields: In India once there were 30,000 varieties of rice

but now only 10 varieties contributes 75% of total production. We are losing our worlds

genetic library

Sustainable Agriculture:

Combine traditional high yield polyculture and modern monoculture Knowledge of traditional sustainable practices has to be transmitted Grow more perennial crops

Minimize soil erosion, salination and water logging Reduce destruction of natural forest, grassland and wetlands Reduce usage of water and fossil fuel Increase usage of organic fertilizers, solar, wind and biomass energy etc.,

WATER LOGGING AND SALINITY

The addition of salts to soil and underlying strata by irrigation water Good quality water contains 200-500 mg/litter soluble salts adds 2-5 mg of salt per

year per hectare - excessive usage of water with inadequate drainage facility

increases water table water will evaporate leaving salts in the land causing

salination.

Rising water table in saline aquifers leads to seepage of salts above the surface salination

Removal of deep rooted trees increase stream flow salination


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Construction of dams in saline area increase groundwater head releasing moresalts in rivers salination in neighbouring lands

Impacts: in initial stage reduces soil productivity kills vegetation productive land into

barren land - reduce food production economic loss loss of biodiversity

Preventive measures: reduction of accession of surface water to groundwater through

sprinkler and drip irrigation lining canals - deep rooted trees along canals remove salt

from deep soil.

Provision of sub surface drainage by excess pumping and lowering the water table

Release of dilution flow from reservoirs maintain stream salinity below critical level

Reclamation: make sub surface drainage system flush the land with pure water make the

water to be drained by sub surface drainage system repeat 4-5 times remove the salts from

soil very costlier method.

ENERGY RESOURCES

ENERGY is defined by physicists as the capacity to do work, it is a physical quantity manifested as

heat, mechanical work, motion etc.,

Modern concept of energy developed by Einstein theory of relativity According to First law of thermodynamics energy can neither created nor destroyed

MEASUREMENT OF ENERGY:

Joule: General representation of energy

Equal to energy dissipated by an electrical current of 1 ampere driven by one volt for onesecond.

Equal to twice the energy of motion in a mass of 1 kilogram moving at 1 meter per second Equal to the amount of heat required to raise the temperature of one pound of water at its

maximum density by one degree Fahrenheit

Erg: is the basic unit of energy now largely utilized = 10-7

Joule


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HEAT ENERGY:

Calorie: is the basic unit of heat energy = 4.184J defined as energy needed to raise thetemperature of 1 gram of water by 1 degree centigrade

BTU (British Thermal Unit): is a measure of large amount of heat energy = 1,506 JouleFuels

are valued by Thermal energy - Btu unitsEg. A pound of coal yields 4,000 to 15,000 Btu while a pound of oil releases 19,000 Btu.

One Btu = 251 calories = 778.26 foot-pound = 1050.18 joulesLarge Units representation:

National wide energy is expressed in exajoule = 1018 (billion) joules = 1 quadrillion (Quad) or10

15Btu

1 Quad = energy released if 172 million barrels (each barrel 159 liters) of oil are burned Us consumes 85 Quads of energy per year.

OTHER MEASUREMENTS OF ENERGY:

Electron Volt: unit of energy equal to the energy transferred when an electron having an electron

volt

Watt: unit of measurement of power (rate at which energy is used). One watt = joule per second or

107

ergs per second

Electrical energy is measured in Watt (We). A light bulb operating in 220 volts and using 0.2ampere of current consumes about 40 watts (220 volts * 0.2amp).

Power: defined as the rate at which work is done. Power is measured in foot-pound pre second or

horse power. 1HP = 550 foot-pounds per second. Used in automobiles, rail engines, gas turbines,

electric motors etc.,

If an engine lifts 550 pound weight to a height of 5 feet in one second it is said to work at arate of 2,750 foot-pounds per second delivering a power of 5HP.

Biological energy: all living organism have to transform energy to maintain their processes.

Human beings are using 2000 calories of energy every day as biological energy to maintaintheir metabolism.


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Besides biological energy developed countries are using 200,000 calories per person fortransportation, heating, television, refrigeration etc.,

Amongst 88% of energy derived from coal, oil, gas and electricity.ENERGY RESOURCES:

Renewable Nonrenewable

Non-Renewable Energy Sources: These consist of the mineral based hydrocarbon fuels coal, oil and

natural gas also called fossil fuels . Oil and gas resources however are likely to be used up within

the next 50 years.

Fossil Fuel:

1. Gas: Natural gas, coal gas etc.,2. Solid Fuel: Anthracite, coke, lignite, peat, charcoal etc.,3. Liquid Fuel: petroleum, Gasoline, kerosene etc.,

Hydrocarbon:

It is a type of oil rich in hydrogen and carbon with very less / no oxygen (Example: Methane,Naphtene)

Petroleum:

The word PETROLEUM originates from the LATIN word. PETRA and OLEUM meaning ROCK and

OIL. It means ROCK OIL or MINERAL OIL

It is a mixture of hydrocarbon molecules and lesser quantities of organic moleculescontaining sulfur, oxygen, nitrogen, and some metals.

The gas that is associated with petroleum, or found separately under the surface of theearth is known as natural gas

The semi-solid or solid part is known as asphalt or tar, Coals, Kerogen, albertite, gilsonite and/ or grahamite


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IN INDIA

According to ONGC report t 18.5 billion tons upto 200 m water depth and 5 to 9 billion tons in the

deep water areas from 200-2000 m isobaths

COAL

It is composed mostly of organic (carbon containing) material, with a smaller amount of inorganic

minerals

Fossil fuel created from the remains of plantsthat lived and died about 100 to 400 million years ago


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Types of coal

Lignite: The lowest grade of coal

Bituminous: Bituminous coal is the most abundant and most widely used coal.

It has a higher heating potential and is used for making coke

Anthracite: This type of coal has the highest percentage of fixed carbon and a lower percentage of

volatile material than all other coals

Indian occurrence

On the basis of their occurrence relative to geological age, coal deposits of India are oftenclassified in to two groups.

Lower Gondwana coals and Tertiary coals, the former being of great economic importance India has only scarce occurrence of lignite type of coal. important deposits reported so for

occur in Tamil Nadu Pondichery,Kutch,Kerala and UP

COAL RESERVES OF INDIA The coal reserves of India, up to the depth of 1200m, have been

estimated by the Geological Survey of India as 2,11,593.61 million tonnes as on 1.1.2000

Energy Trend

Between 1900 and 2000 world population increased three times but energy consumptionincreased 14 times


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For almost 200 years, coal was the primary energy source fuelling the industrial revolution in the 19th century. At the close of the 20th century, oil accounted for 39% of the worlds commercial energy

consumption, followed by coal (24%) and natural gas (24%), while nuclear (7%) and

hydro/renewables (6%) accounted for the rest

Amongst oil and coal creates more environmental problems while gas is almost a cleanenergy

The trend of 21st century is move from fuels with more carbon atoms to few or no carbonatoms called as Decarbonization

Coal = C:H ratio 1:5 Oil = 1:2 Gas = 1:4 Hydrogen = 0:1

Indian scenario

India fourth largest economy with an energy demand of 30% Coal accounts 63.3%; Petroleum-18.6%; Hydro-electricity-8.9; Gas-8.2and Nuclear-1%. Overall energy production was 16.4 Quads. Annually there is a 4.6% demand.

Environmental problems

Oil and its environmental impacts:

The processes of oil and natural gas drilling, processing, transport and utilisation haveserious environmental consequences, such as leaks in which air and water are polluted.

Oil powered vehicles emit carbon dioxide, sulphur dioxide, nitrous oxide, carbon monoxideand particulate matter which is a major cause of air pollution especially in cities with heavy

traffic density

Coal and its environmental impacts: Coal is the worlds single largest contributor of green house

gases and is one of the most important causes of global warming.

Burning coal also produces oxides of sulphur and nitrogen which, combined with watervapour, lead to acid rain.

Renewable energy

Hydroelectric Power

This uses water flowing down a natural gradient to turn turbines to generate electricityknown as hydroelectric power by constructing dams across rivers.


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In 1882, the first Hydroelectric power dam was built in Appleton, Wisconsin. In India the firsthydroelectric power dams were built during 1897 in Darjeeling

Between 1950 and 1970, Hydropower generation worldwide increased seven times. Major hydroelectric projects in India: Mettur, Bhakra nangal, Hirakud, Damodar,

Nagarjunasagar, Idukki, Tungabadra and Koyna

Advantages: The long life of hydropower plants, the renewable nature of the energy source, very

low operating and maintenance costs, and absence of inflationary pressures as in fossil fuels

Disadvantages:

To produce hydroelectric power, large areas of forest and agricultural lands are submerged Silting of the reservoirs (especially as a result of deforestation) reduces the life of the

hydroelectric power installations

Water is required for many other purposes besides power generation including domestic,agricultural, industry etc., - gives rise to conflicts.

The use of rivers for navigation and fisheries becomes difficult once the water is dammed Large dams can induce seismic activity which will result in earthquakes.

SOLAR ENERGY

In one hour, the sun pours as much energy onto the earth as we use in a whole year. Problem with solar energy is its availability during day time, less under cloudy conditions and

its non availability in poles

Utilization of solar energy:

Heat generation:

Passive heating system: solar energy directly converted into heat and used at the site where it is

collected

Solar water heating system: consist of flat plate aluminium or copper with copper tubes(riser), insulated storage tank, insulated pipes for hot/cold water circulation, control

instruments. Eg. Solar desalination system - Preparation of distilled water from brackish

water.

Solar rice cocker.


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SPV (Solar Photo voltaic cells) solar radiation is converted into to DC electricity directly canbe used as it is or stored in batteries and can be used at night

o Uses: domestic lighting, street light, water pumping, desalination, railway signals,remote telecommunication systems etc.,

oElectricity generation:

For achieving higher temperature (2000oc) parabolic mirrors are used to focus radiation in aconcentrated manner over a collector

For still higher temperature series of parabolic mirrors called as heliostats are arranged insuch a way the radiation is focused onto a central receiver located on the tower.

Active heating system: converted into heat but from places of collection it is transferred to the placeof use

Solar pond: when water in pond is heated it raises up and losses its energy to atmosphere

In solar pond salt is dissolved in the bottom layer which will arrest the upward movement

Solar pond has three zones

1. upper convection zone which is at atmospheric temperature and has little salt content2. Lower convection zone: The bottom zone is at 70-850C and is very salty where solar energy is

stored in the form of heat

3. Non convective zone: it is the important gradient zone where salinity or density increases with depth If we consider single layer in this zone water cannot move up since the water in the

above layer is lighter or cannot move down since it is heavier due to comparatively more

salt content

This zone act as transparent insulator permitting the sunlight to reach the bottom zoneand tapping the heat energy in the bottom zone

Ocean thermal energy:

The solar energy absorbed by the tropical oceans in a week could equal the entire oilreserves of the world

60 million square kilometre of tropical sea absorb radiation equivalent to the heat contentof 24 billion barrels of oil.


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Top of the sea will be hot while bottom is with low temperature - difference of 20oC Low boiling liquids like ammonia, butane etc., can be used for extracting this heat and

subsequently converted into electrical energy.

These plants are known as Ocean Thermal Energy Conversion (OTEC).Ocean Currents:

Ocean currents are generated due to variation in solar radiation and Coriolis effect. Making circular flow in each basins with clockwise rotation in northern hemisphere and

anticlockwise rotation in southern hemisphere

These currents are stronger along coastlines. Power can be generated by keeping propellermounted with gears at a depth of 10 to 20 meters.

Tidal Power:

The energy of waves in the sea that crash on the land of all the continents is estimated at 2to 3 million megawatts of energy.

Tidal power is tapped by placing a barrage across an estuary and forcing the tidal flow topass through turbines.

In a one-way system the incoming tide is allowed to fill the basin through a sluice, and thewater so collected is used to produce electricity during the low tide.

In a two way system power is generated from both the incoming as well as the outgoingtide.


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Environmental Impacts:destroy the habitats and nesting places of water birds and interfere withfisheries.A tidal power station at the mouth of a river blocks the flow of polluted water into the sea,thereby creating health and pollution hazards in the estuary

Biomass energy:

Biomass is organic material which has stored sunlight in the form of chemical energy.In the process of photosynthesis plants converts radiant energy from the sun into chemical

energy in the form of glucose or sugar

Water (6H2O)+ carbon dioxide (6CO2) + Sunlight glucose (C2H12O2) + oxygen 6O2)

Biomass includes wood, agricultural waste, sugarcane wastes etc.,

There are three ways to use biomass.

1. burned to produce heat and electricity,2. changed to a gas-like fuel such as methane or3. changed to a liquid fuel also called biofuels includes two forms of alcohol: ethanol and

methanol. (biodiesel made from vegetable oils)

Biomass when burned or converted into energy creates air pollution including carbondioxide and less sulphur dioxide. Rate of pollution is relatively less compared to fossil fuels.

Biogas:

Biogas is produced from plant material and animal waste, garbage, waste from householdsand some types of industrial wastes, such as fish processing, dairies, and sewage treatment

plants

It is a mixture of gases which includes methane, carbon dioxide, hydrogen sulphide andwater vapour.

In a ton of food waste 85 Cu. M of biogas can be produced and residues can be used asfertilizer.

The biogas plants use cowdung, which is converted into a gas which is used as a fuel. The fibrous waste of the sugar industry is the worlds largest potential source of biomass

energy.

Ethanol produced from sugarcane molasses is a good automobile fuel


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Wind Power:

Wind was the earliest energy source used for transportation by sailing ships. Some 2000 years ago, windmills were developed in China, Afghanistan and Persia to draw

water for irrigation and grinding grain

At present, India is the third largest wind energy producer in the worldEnvironmental Impacts:bird kills, noise, effect on TV reception, and aesthetic objectionsGeothermal energy:

Geothermal energy comes from the heat within the earth. The word "geothermal" comes from the

Greek words geo, meaning earth," and therme, meaning "heat."

The earth's core lies almost 4,000 miles beneath the earth's surface. The double-layered core is

made up of very hot molten iron surrounding a solid iron center. Estimates of the temperature of

the core range from 5,000 to 11,000 degrees Fahrenheit (F). Heat is continuously produced within

the earth by the slow decay of radioactive particles that is natural in all rocks.

Surrounding the earth's core is the mantle, thought to be partly rock and partly magma. Themantle is about 1,800 miles thick. The outermost layer of the earth, the insulating crust, is

not one continuous sheet of rock, like the shell of an egg, but is broken into pieces called

plates. These slabs of continents and ocean floor drift apart and push against each other at

the rate of about one inch per year in a process called continental drift.

Magma (molten rock) may come quite close to the surface where the crust has been thinned,

faulted, or fractured by plate tectonics. When this near-surface heat is transferred to water, a usable

form of geothermal energy is created

Geothermal energy is called a renewable energy source because the water is replenished byrainfall, and the heat is continuously produced by the earth.

Some visible features of geothermal energy are volcanoes, hot springs, geysers, and fumaroles

There are four main kinds of geothermal resources: hydrothermal, geopressured, hot dryrock, and magma. Today hydrothermal resources are the only kind in wide use. The other

three resources are still in the infant stages of development.

Nuclear Power

Atom is made up of nucleus of protons and neutrons surrounded by electrons


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Fission:

In 1938 two German scientists Otto Hahn and Fritz Strassman demonstrated nuclear fission(splitting of atom).

They split the nucleus of a uranium atom by bombarding it with neutrons Energy in the form of heat and light is released

Fusion: when tow hydrogen atom combine to produce helium atom (Sun)

The first large-scale nuclear power plant in the world became operational in 1957 inPennsylvania, US.

Dr. Homi Bhabha was the father of Nuclear Power development in India. India has 10 nuclear reactors at 5 nuclear power stations that produce 2% of Indias

electricity.

These are located in Maharashtra (Tarapur), Rajasthan, Tamil Nadu, Uttar Pradesh andGujrat. India has uranium from mines in Bihar.

There are deposits of thorium in Kerala and Tamil Nadu. The nuclear reactors use Uranium 235 to produce electricity. Energy released from 1kg of

Uranium 235 is equivalent to that produced by burning 3,000 tons of coal. U235 is made into

rods which are fitted into a nuclear reactor. The control rods absorb neutrons and thus adjust the fission which releases energy due to

the

chain reaction in a reactor unit. The heat energy produced in the reaction is used to heat water and produce steam, which

drives turbines that produce electricity.

The drawback is that the rods need to be changed periodically. This has impacts on theenvironment due to disposal of nuclear waste. The reaction releases very hot waste water

that damages aquatic ecosystems, even though it is cooled by a water system before it isreleased.

Indian nuclear programme has three stages.

Stage I: use of Pressurized Heavy Water Reactors (PHWRs) for nuclear power generation; Stage II:

Fast Breeder Reactors (FBR);

Stage III: Thorium Based Reactors (TBR). The stage I is operational and Stage II and III are under

development.


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Water reactors of stage I require U-235 as fuel. But Indians Uranium resource is very limited

and hence import from other countries is inevitable. However, in Fast Breeder Reactor U-238 and

Th-232 are used as primary fuel, but they are not readily fissionable. Therefore in the breeder

reactor U-238 and Th-232 are converted into fissionable Plutonium 239 (Pu-239) and U-233

respectively and more fuel is generated and hence called breeder reactor. Stage 3 of Indian Nuclear

Programme focuses the use of reactor fuelled by Thorium- 232. India has a sizable quantity of

Thorium resources as against Uranium. A prototype fast breeder reactor is functioning at Indira

Gandhi Centre for Atomic Research (IGCAR), Kalpakkam and KAMINI (Kalpakkam Mini), a thorium

based reactor has been designed and tested at a preliminary level.

Atomic Energy Green Energy

Among other modes of electricity generation, Nuclear power is environmental friendly in a sense

that there is no emission of CO2 or other Green House Gases such as a NOx, SOx, O3 and CFC.

Energy Conservation

India needs to rapidly move into a policy to reduce energy needs and use cleaner energyproduction technologies

India must reduce its dependency on imported oil. At present we are under-utilizing our natural gas resources We could develop thousands of mini dams to generate electricity Fuel wood plantations need to be enhanced.


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LAND RESOURCES

SOIL :

Loose (Un-consolidated) material/organic matter capable of supporting Plant growth

CLASSIFICATION

Non Soil: surface material that donot support plant life (Eg. Salt flat, rock barrensetc.,)

Mineral Soil: Formed by dissolving and disintegration of rocks Organic Soil: Develop from accumulation of plant residues that are preserved by low

oxygen environment of shallow and stagnant waters (Eg. Tundras, peat bogs, peat

soils)

SOIL FORMATION

PEDOGENESIS is the term used to describe the formation and development of soilprofile

Soil Horizon

They are the layers of the different types of soil found at different depths in soil

profile.

o Horizonorganic layero A Horizontopsoilo B Horizonsubsoilo C Horizonsubstratumo

R Horizonbedrock

SOIL CLASSIFICATION

o TAXONOMY: Greek work taxis meaning arrangement or ordero SOIL TAXONOMY: Scientific grouping of similar soils.o General soil category is ORDER, all the world soil is placed under 10 order

Classification of Indian Soils

There are 8 major group of soils in India which are furnished below


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Red Soils

Red colour is due to various oxides of iron. They are poor in N, P, K and with pHvarying 7 to 7.5.

Red soils occurs extensively in Andhra Pradesh , Assam, Bihar, Goa, Parts of kerala,Maharastra, Karnataka, Tamilnadu and West Bengal. Most of the red soils have been

classified in the order ' Alfisols'.

Lateritic Soils

Seen in high rainfall areas, under high rainfall conditions silica is released andleached down wards and the upper horizons of soils become rich in oxides of

iron and aluminum..

They are distributed in summits of hills of Daccan karnataka, Kerala,Madhyapradesh, Ghat regions of Orissa, Andhra pradesh, Maharastra and also

in West Bengal, Tamilnadu and Assam.

Most of the laterite soils have bee classified in the order ' ultisols' and a fewunder ' oxisols'.

Alluvial Soils

These are the most important soils from the agriculture point of view. Thesoils are sandy loam to clay loam with light grey colour to dark colour,

structure is loose and more fertile.

These soils are distributed in Indo-Gangetic plains, Brahmaputra valley and allmost all states of North and South. Most of the alluvial soils have been

classified in the orders ' Entisols', ' Inceptisols' and ' Alfisols'.

Black Soils

This is well known group of soils characterised by dark grey to black colour with highclay content.

Major black soils are found in Maharastra, Madhyapradesh, Gujarat and Tamilnadu. Cotton is most favourable crop to be grown in these soils. These soils are classified in

the order 'Entisols', ' Inceptisols' and ' vertisols'.

Forest Soils

This group of soils occur in Himalayas. Soils are dark brown with more sub-soilhumus content. They are more acidic.

Desert Soils

These soils are mostly sandy to loamy fine sand with brown to yellow brown colour,contains large amounts of soluble salts and lime with pH ranging 8.0 to 8.5.

The presence of Phosphate and Nitrate make the desert soils fertile and productiveunder water supply. They are distributed in Haryana, Punjab, Rajasthan. They are

classified in the order ' Aridisols' and ' Entisols'.


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Peaty and Marshy Soils

These soils occur in humid regions with accumulation of high organic matter. Duringmonsoons the soils get submerged in water and the water receipts after the monsoon

during which period rice is cultivated. Soils are black clay and highly acidic with pH

of 3.5. Free alluminium and ferrous sulphate are present.

The depressions formed by dried rivers and lakes in alluvial and coastal areas sometimes give rise to water logged soils and such soils are blue in colour due to the

presence of ferrous iron.

Peaty soils are found more in Kerala and marshy soils are found more in coastaltracks of Orissa, West Bengal and South - East coast of Tamilnadu.

Saline - Sodic Soils

Saline soils contain excess of natural soluble salts dominated by chlorides andsulphates which affects plant growth. Sodic or alkali soils contain high exchangeable

sodium salts. Both kinds of salt effected soils occur in different parts of India like Uttarpradesh,

Haryana, Punjab, Maharastra, Tamilnadu, Gujarat, Rajastan and Andhra pradesh.

These soils are classified under ' Aridisols', ' Entisols' and ' Vertisols'.

SOIL EROSION :

Process of detachment & Transportation of soil materials by erosion agents!

Erosion is the carrying away or displacement of solids (sediment ,rock andother particles)

usually by the agents of currents such as, wind, water, or iceWhy is it important?

Soil loss Nutrient loss Reduction of infiltration (surface sealing) Effects on aquatic organisms Fills reservoirs Effects on drinking water quality

Erosion prone areas

high-intensity precipitation,

more frequent rainfall, more wind, or more storms Sediment with high sand or silt contents areas with steep slopes highly fractured or weathered rock. Sediment containing more clay tend to erode less than those with sand or silt.


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Effects

Approximately 40% of the world's agricultural land is seriously degraded An area of fertile soil the size of Ukraine is lost every year because of drought,

deforestation and climate change

When land is overused by animal activities (including humans), there can bemechanical erosion

most serious and long-running water erosion problems worldwide is in the chinaon the middle reaches of the yellow river and the upper reaches of the yangtze

river.

From the yellow river, over 1.6 billion tons of sediment flows into the ocean eachyear

SOIL EROSION : TYPES

i) Water

ii) Wind

Soil Erosion by Water :

1.Splash erosion: due to impact of raindrops on the surface.Raindrops fall at a speedof about 20 miles per hour.

2.Sheet erosion: due to surface flow by gravity after raindrop splash

3.Rill erosion : Channel development on recently cultivated soils---due to

greater sourcing action by concentrated flow of water

4.Gully erosion : Enlarged features of rillsmay yield tremendous volumes ofsediment by large conc. Of run-off .Gullies enlarge until they become permanent

topographic features.

5.Channel Erosion :

-Introduces gully erosion,

-Stream bank erosion,

-Valley trenching,

-Degradation & flood plain scour.

6. Gross Erosion :-Its the Summation of erosion from all sources within the watershed.

Soil erosion by Wind

Types of soil movement :

1. Suspension : < 0.05mm diameter - silt size & smaller2. Saltation : > 0.05 0.5 mm very fine to medium sand3. Surface creep : > 0.5 mm diameter of particles

Controlling factors of soil Erosion


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Erosive potential of an area depends on :

Climate: rain drop size, intensity, distribution, fall, velocities, total mass of impact &temperature!

Characteristics of soil : texture, structure, permeability, compactness & infiltrationcapacity!

Vegetal cover : vegetation types, density, root systems! Topography : slope length, slope configuration & surficial features! Human activities : landuse, construction practices, agro-applications, landuse

conversion to rocky wastes, deforestation, industrial waste disposals, mine & mine

waste gushings.

MEASUREMENT OF SOIL EROSION

The Universal Soil Loss Equation (USLE) designed by two soil scientists namely,

Wischmeier and Smith during the year 1978 is to predict the soil loss in the field.

A = Soil loss in tons/ha/year

R=rainfall-runoff erosivity factor

K=soil erodability factor

L=slope length factorS=slope steepness factor

C = vegetative cover factor

P = conservation practice factor

SOIL EROSION : IMPACTS

A.Environmental Impacts

Suspended Nutrientstrigger algal bloom---reduces water clarity---depletes Oxygen---fish kill---Odorcreation

Stream bank & adjacent areas erosion destroys: -stream vegetation---endangers

aquatic & wild life!

Excessive stream deposition: Sediment Turbidity: -reduces in-stream Photosynthesis---reduced food supply &

habitat!

Suspended coasts: -Abrades coasts & Aquatic organisms Obstructed Vegetal growth -due erosion removes the nutrients


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B) Economic Impacts

Excessive sediment accumulation: -reduces reservoir storage capacity Erosion: -Severely diminishes the ability of the soil to support plant growth

-thus, the loss in Agricultural Productivity

Damages engineering structures: -eg. Abrasion in Hydel dams & reservationsSOIL CONSERVATION

Why is soil conservation important?

"A nation that destroys its soil destroys itself." - President Franklin D. Roosevelt,1937

Worldwide, an estimated 26 billion tons of topsoil are washed or blown off croplandeach year. Every year 6 million hectares of productive land become desert

Vegetative methods of soil stabilization

Vegetal cover reduces erosion by,- absorbing the impact of raindrops

- reducing the velocity of run-off

- reducing run-off volumes by increasing water

percolation in the soil- Binding soil with roots

- protecting soil from wind

These methods need :

- careful selection of plants,

- Site preparation, seeding,- Fertilizing & mulching

on the basis of effectiveness for soil erosion control in that particular terrain.

Mechanical methods of soil erosion control

Contouring / contour cultivation, contour strip cropping Contour bunds Terracing, Terrace cultivation, Water conveyance structures

- Check dams

- Pipe slope drains

- permanent waterways

- Geotextiles


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DESERTIFICATION

The processes of conversion of crop or rage land into desert-like land, with a drop inagriculture productivity.

Causes: overgrazing, deforestation, surface mining, unscientific farming practice, overcultivation etc.,

Environmental Studies Unit i 1

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Transcript of Environmental Studies Unit i 1