Perspectives in Environmental Studies PDF

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Downloaded From : www.EasyEngineering.net ww w.E a syE ngi nee rin g.n et **Note: Other Websites/Blogs Owners Please do not Copy (or) Republish this Materials, Students & Graduates if You Find the Same Materials with EasyEngineering.net Watermarks or Logo, Kindly report us to [email protected] Downloaded From : www.EasyEngineering.net  Downloaded From : www.EasyEngineering.net ww w.E asy En gin eer ing. net Downloaded From : www.EasyEngineering.net  Downloaded From : www.EasyEngineering.net PERSPECTIVES IN ENVIRONMENTAL STUDIES ww w.E asy En gin ee rin g.n et Downloaded From : www.EasyEngineering.net  Downloaded From : www.EasyEngineering.net THIS PAGE IS ww BLANK w.E asy En gin ee rin g.n et Downloaded From : www.EasyEngineering.net  Downloaded From : www.EasyEngineering.net ww w.E asy En gin ee rin g.n et Downloaded From : www.EasyEngineering.net  Downloaded From : www.EasyEngineering.net ww w.E asy Copyright © 2004, New Age International (P) Ltd., Publishers En Published by New Age International (P) Ltd., Publishers gin All rights reserved. No part of this ebook may be reproduced in any form, by photostat, microfilm, ee xerography, or any other means, or incorporated into any information retrieval system, electronic or mechanical, without the written permission of the publisher. All inquiries should be emailed to [email protected] rin g.n ISBN (13) : 978-81-224-2345-7 et PUBLISHING FOR ONE WORLD NEW AGE INTERNATIONAL (P) LIMITED, PUBLISHERS 4835/24, Ansari Road, Daryaganj, New Delhi - 110002 Visit us at www.newagepublishers.com Downloaded From : www.EasyEngineering.net  Downloaded From : www.EasyEngineering.net ww w.E asy Dedicated with Reverence to Memories of Our En FATHER, LATE PROF. A.K. SINHA gin A Great Philosopher, Educationist and Humanist & ee MOTHER, LATE SMT. ASHA RANI KAUSHIK rin An Embodiment of Love and Dedication g.n et Downloaded From : www.EasyEngineering.net  Downloaded From : www.EasyEngineering.net THIS PAGE IS ww BLANK w.E asy En gin ee rin g.n et Downloaded From : www.EasyEngineering.net  Downloaded From : www.EasyEngineering.net ww w.E asy En gin ee rin g.n et Downloaded From : www.EasyEngineering.net  Downloaded From : www.EasyEngineering.net ww w.E asy En gin ee rin g.n et Downloaded From : www.EasyEngineering.net  Downloaded From : www.EasyEngineering.net ww w.E asy En gin ee rin g.n et Downloaded From : www.EasyEngineering.net  Downloaded From : www.EasyEngineering.net THIS PAGE IS ww BLANK w.E asy En gin ee rin g.n et Downloaded From : www.EasyEngineering.net  Downloaded From : www.EasyEngineering.net (ix) CORE MODULE SYLLABUS FOR ENVIRONMENTAL STUDIES FOR UNDERGRADUATE COURSES OF ALL BRANCHES OF HIGHER EDUCATION Unit 1 : The Multidisciplinary Nature of Environmental Studies Definition, scope and importance (2 Lectures) ww Need for public awareness. Unit : 2 : Natural Resources w Renewable and non-renewable resources : Natural resources and associated problems..Ea (a) Forest resources : Use and over-exploitation, deforestation, case studies. Timber extraction, mining, dams and their effects syE on forests and tribal people. (b) Water resources : Use and over-utilization of surface and benefits and problems. ngi ground water, floods, drought, conflicts over water, dams- (c) Mineral resources : Use and exploitation, environmental ef- nee fects of extracting and using mineral resources, case studies. (d) Food resources : World food problems, changes caused by rin agriculture and over-grazing, effects of modern agriculture, fertilizer-pesticide problems, water logging, salinity, case studies. (e) Energy resources : Growing energy needs, renewable and g.n non-renewable energy sources, use of alternate energy sources, Case studies. (f ) Land resources : Land as a resource, land degradation, man induced landslides, soil erosion and desertification. e t • Role of an individual in conservation of natural resources. • Equitable use of resources for sustainable life styles. (8 Lectures) Unit 3 : Ecosystems • Concept of an ecosystem. • Structure and function of an ecosystem. • Producers, consumers and decomposers. • Energy flow in the ecosystem. • Ecological succession. • Food chains, food webs and ecological pyramids. Downloaded From : www.EasyEngineering.net DHARM D:\N-ENVIR\SYL  Downloaded From : www.EasyEngineering.net (x) • Introduction, types, characteristic features, structure and func- tion of the following ecosystem : (a) Forest ecosystem (b) Grassland ecosystem (c) Desert ecosystem (d) Aquatic ecosystem (ponds, streams, lakes, rivers, oceans, ww estuaries). Unit 4 : Bio-diversity and its Conservation (6 Lectures) w • Introduction—Definition : genetic, species and ecosystem.Ea diversity. • Biogeographical classification of India. syE • Value of biodiversity : consumptive use, productive use, social, ethical, aesthetic and option values. • Biodiversity at global, national and local levels. ngi • India as a maga-diversity nation. • Hot-spots of biodiversity. nee • Threats to biodiversity : habitat loss, poaching of wildlife, man-wildlife conflicts. • Endangered and endemic species of India. rin • Conservation of biodiversity : In-situ and Ex-situ conserva- tion of biodiversity. Unit 5 : Environmental Pollution g.n (8 Lectures) Definition • Causes, effects and control measures of : (a) Air pollution e t (b) Water pollution (c) Soil pollution (d) Marine pollution (e) Noise pollution (f ) Thermal pollution (g) Nuclear hazards. • Solid waste management : Causes, effects and control meas- ures of urban and industrial wastes. • Role of an individual in prevention of pollution. • Pollution case studies. • Disaster management : floods, earthquake, cyclone and land- slides. (8 Lectures) Downloaded From : www.EasyEngineering.net DHARM D:\N-ENVIR\SYL  Downloaded From : www.EasyEngineering.net (xi) Unit 6 : Social Issues and the Environment • From Unsustainable to Sustainable development. • Urban problems related to energy. • Water conservation, rain water harvesting, watershed man- agement. • Resettlement and rehabilitation of people: its problems and ww concerns. Case studies. • Environmental ethics: Issues and possible solutions. w • Climate change, global warming, acid rain, ozone layer de- pletion, nuclear accidents and holocaust. Case studies..Ea • Wasteland reclamation. • Consumerism and waste products. syE • Environment Protection Act. • Air (Prevention and Control of Pollution) Act. ngi • Water (Prevention and Control of Pollution) Act. • Wildlife Protection Act. • Forest Conservation Act. nee • Issues involved in enforcement of environmental legislation. • Public awareness. (7 Lectures) Unit 7 : Human Population and Environment rin • Population growth, variation among nations. • Population explosion—Family Welfare Programme. g.n • Environment and human health. • Human Rights. • Value Education. e t • HIV/AIDS. • Women and Child Welfare. • Role of Information Technology in Environment and human health. • Case Studies. (6 Lectures) Unit 8 : Field Work • Visit to a local area to document environmental assets—river, forest grassland/hill/mountain. • Visit to a local polluted site—Urban/Rural/Industrial/ Agricultural. • Study of common plants, insects and birds. • Study of simple ecosystems—pond, river, hill slopes etc. (Field work Equal to 5 lecture hours) (5 Lectures) Downloaded From : www.EasyEngineering.net DHARM D:\N-ENVIR\SYL  Downloaded From : www.EasyEngineering.net THIS PAGE IS ww BLANK w.E asy En gin ee rin g.n et Downloaded From : www.EasyEngineering.net  Downloaded From : www.EasyEngineering.net Contents (as per UGC module Syllabus) wwPreface 1. Environmental Studies—A Multidisciplinary Subject (vii) 1 w 2. Natural Resources.Ea 2.1 Forest Resources 2.2 Water Resources 5 6 13 syE 2.3 Mineral Resources 2.4 Food Resources 2.5 Energy Resources 23 30 38 3. 2.6 Land Resources Ecosystems ngi 53 65 4. 5. Environmental Pollution nee Biodiversity and its Conservation 98 123 6. 7. Social Issues and the Environment Human Population and the Environment rin 161 211 8. Field Work Suggested Readings g.n 236 243 Glossary Index e 244 254 t (xv) Downloaded From : www.EasyEngineering.net  Downloaded From : www.EasyEngineering.net THIS PAGE IS ww BLANK w.E asy En gin ee rin g.n et Downloaded From : www.EasyEngineering.net  Downloaded From : www.EasyEngineering.net Unit 1 Environmental Studies —A Multidisciplinary Subject ww ‘Environment’ is derived from the French word Environner which means to encircle or surround. All the biological and non-biological things surrounding an organism are thus included in environment. Thus w.Eenvironment is sum total of water, air and land, inter-relationships among themselves and also with the human beings, other living organ- isms and property. The above definition given in Environment (Protec- asy tion) Act, 1986 clearly indicates that environment includes all the physi- cal and biological surroundings and their interactions. Thus, in order En to study environment one needs knowledge inputs from various disci- plines. Life Sciences including Botany, Zoology, Microbiology, Genet- ics, Biochemistry and Biotechnology help in understanding the biotic gin component and their interactions. The physical and chemical struc- ture of the abiotic components and energy transfer and flow are under- ee stood with the help of basic concepts of Physics, Chemistry, Geology, Atmospheric Science, Oceanography and Geography. Mathematics, rin Statistics and Computer Science serve as effective tools in environmental modeling and management. Subjects like Education, Economics, So- g.n ciology and Mass communication provide the inputs for dealing with the socio-economic aspects associated with various developmental ac- ing, Hydraulics and Chemical Engineering form the basis for various et tivities. A synthesis with Environmental Engineering, Civil Engineer- technologies dealing with the control of environmental pollution, waste- treatment and development of cleaner technologies that are important for protection of the environment. Environmental laws provide the tools for effective management and protection of the environment. Environ- mental Studies, therefore, is a multi-disciplinary subject where differ- ent aspects are dealt with a holistic approach. Scope Scope of environmental studies is broad based and it encompasses a large number of areas and aspects, broadly listed below: 1 Downloaded From : www.EasyEngineering.net  Downloaded From : www.EasyEngineering.net 2 Environmental Science and Engineering l Natural Resources—their conservation and management l Ecology and biodiversity l Environmental pollution and control l Social issues in relation to development and environment l Human population and environment These are the basic aspects of Environmental Studies which have a direct relevance to every section of the society. Environmental studies can be highly specialized also which may concentrate on more technical aspects like Environmental Science, Environmental Engineering, ww Environmental Management, Environmental Biotechnology etc. Environment belongs to all and is thus important for all. Whatever be the occupation or age of a person, he or she will be affected by w.Eenvironment and will also affect the environment by his or her deeds. Thus, environment is one subject that is actually global in nature. For example, atmosphere has no boundaries and the pollutants produced asy at one place can be dispersed and transported to another place. The river water polluted by industrial or municipal discharge at one point would seriously affect the downstream aquatic life. Damage to the En forests in a hilly region will have far reaching effect not only on the hills but also on the plains. This is because environment is a closely gin and intricately woven network of components and functions. There are some environmental problems which may be of localized ee importance but there are some major issues like global warming, depletion of ozone layer, dwindling forests and energy resources, loss rin of global biodiversity etc. that are going to affect the mankind as a whole and for that we have to think globally. For dealing with local g.n environmental issues, e.g. the impacts of mining or hydro-electric projects, solid waste management etc. we have to think and act locally. et In order to make the people aware about those aspects of environment with which they are so intimately associated, it is very important to make every one environmentally educated. Environmental studies is very important since it deals with the most mundane issues like safe and clean drinking water, hygienic living conditions, clean and fresh air, fertile land, healthy food and development that is sustainable. There is a need for trained manpower at every level to deal with environmental issues. Environmental law, business administration and environmental engineering are emerging as new career opportunities for environmental protection and management. With the pollution control laws becoming more stringent, industries are finding it difficult to dispose off the produced wastes. In order to avoid expensive litigation, various companies are now trying Downloaded From : www.EasyEngineering.net  Downloaded From : www.EasyEngineering.net Environmental Studies—A Multidisciplinary Subject 3 to adopt green technologies, which would reduce pollution. Investing in pollution control technologies will reduce pollution as well as cut on costs for effluent treatment. Market for pollution control technology is huge the world over. Cleaning up of the wastes produced is another potential market. It is estimated to be more than $ 100 billion per year for all American business. Germany and Japan having more stringent laws for many years have gained more experience in reducing effluents. Still there is a $ 200 billion market for cleaning up the former east Germany alone. In India also the Pollution Control Boards are seriously implementing pollution control laws and insisting on upgradation of ww effluents to meet the prescribed standards before they are discharged on land or into a water body. Many companies not complying with the orders have been closed or ordered to shift. This is infact essential if we w.Ewant to live in a clean, healthy, aesthetically beautiful, safe and secure environment for a long time and wish to hand over a clean and safe earth to our children, grand-children and great grand children. asy Need for Public Awareness The United Nations Conference on Environment and Development En held in Rio de Janeiro in 1992 and popularly known as ‘Earth Sum- mit’ followed by the World Summit on Sustainable Development at gin Johannesburg in 2002, just 10 years after the first summit, have high- lighted the key issues of global environmental concern and have at- ee tracted the attention of the general public towards the deteriorating environment. Any government at its own level cannot achieve the goals rin of sustainable development until the public has a participatory role in it. Public participation is possible only when the public is aware about g.n the ecological and environmental issues. A drive by the government to ban the littering of polythene cannot be successful until the public un- derstands the environmental implications of the same. The public has to be educated about the fact that if we are degrading our environment et we are actually harming our ownselves. This is because we are a part of the complex network of environment where every component is linked to another. It is all the more important to educate the people that some- times the adverse impact of environment are not experienced or no- ticed until a threshold is crossed. So we may be caught unawares by a disaster. There is a Chinese proverb “It you plan for one year, plant rice, if you plan for 10 years, plant trees and if you plan for 100 years, educate people.” If we want to manage our planet earth, we have to make all the persons environmentally educated. Downloaded From : www.EasyEngineering.net  Downloaded From : www.EasyEngineering.net 4 Environmental Science and Engineering In 1991, the Supreme Court of our country issued directive to make all curricula environment-oriented. This directive was, in fact, in response to a Public Interest Litigation (PIL) filed by M.C. Mehta vs. Union of India (1988) that prompted the apex court to give a mandate for creating environmental awareness among all citizens of India. Today everybody talks of environment, but only a few have clear ideas about what needs to be done and still fewer have the actual experience or expertise in the field. Unfortunately, environmental awareness campaigns have very often been exploited for political propaganda rather than being an integral part of our educational ww programmes in theory and practice. “Environment” is very wrongly taken as a “fashion” by all walks of life, hardly realizing that it is our “real-life-situation” and our sustenance and security are at stake. Henry w.ED. Thoreau rightly says “What’s the use of a beautiful house if you don’t have a decent planet to put it on?” Even if we begin today, the restoration is expected in the next 40-50 years. asy QUESTIONS En 1. What is the need for studying environmental issues ? 2. What is the scope of environmental education ? gin 3. How would environmental awareness help to protect our environment ? ee rin g.n et Downloaded From : www.EasyEngineering.net  Downloaded From : www.EasyEngineering.net Unit 2 Natural Resources Life on this planet earth depends upon a large number of things and ww services provided by the nature, which are known as Natural resources. Thus water, air, soil, minerals, coal, forests, crops and wild life are all examples of natural resources. w.E The natural resources are of two kinds: l Renewable resources which are inexhaustive and can be regenerated within a given span of time e.g. forests, wildlife, asy wind energy, biomass energy, tidal energy, hydro power etc. Solar energy is also a renewable form of energy as it is an En inexhaustible source of energy. l Non-renewable resources which cannot be regenerated e.g. gin Fossil fuels like coal, petroleum, minerals etc. Once we exhaust these reserves, the same cannot be replenished. Even our renewable resources can become non-renewable if we ee exploit them to such extent that their rate of consumption exceeds their rin rate of regeneration. For example, if a species is exploited so much that its population size declines below the threshold level then it is not able g.n to sustain itself and gradually the species becomes endangered or extinct. It is very important to protect and conserve our natural resources and use them in a judicious manner so that we don’t exhaust them. It et does not mean that we should stop using most of the natural resources. Rather, we should use the resources in such a way that we always save enough of them for our future generations. In this unit we shall discuss the major natural resources: (i) Forest resources (ii) Water resources (iii) Mineral resources (iv) Food resources (v) Energy resources (vi) Land resources. 5 Downloaded From : www.EasyEngineering.net  Downloaded From : www.EasyEngineering.net 6 Environmental Science and Engineering 2.1 FOREST RESOURCES Forests are one of the most important natural resources on this earth. Covering the earth like a green blanket these forests not only produce innumerable material goods, but also provide several environmental services which are essential for life. About 1/3rd of the world’s land area is forested which includes closed as well as open forests. Former USSR accounts for about a 5th ww of the world’s forests, Brazil for about a 7th and Canada and USA each for 6-7%. But it is a matter of concern that almost everywhere the cover of the natural forests has declined over the years. The greatest loss w.Eoccurred in tropical Asia where one third of the forest resources have been destroyed. asy n USES OF FORESTS Commercial uses: Forests provide us a large number of commercial En goods which include timber, firewood, pulpwood, food items, gum, resins, non-edible oils, rubber, fibers, lac, bamboo canes, fodder, gin medicine, drugs and many more items, the total worth of which is estimated to be more than $ 300 billion per year. ee Half of the timber cut each year is used as fuel for heating and cooking. One third of the wood harvest is used for building materials rin as lumber, plywood and hardwood, particle board and chipboard. One sixth of the wood harvest is converted into pulp and used for paper g.n industry. Many forest lands are used for mining, agriculture, grazing, and recreation and for development of dams. Ecological uses: While a typical tree produces commercial goods worth about $ 590 it provides environmental services worth nearly $ 196, 250. The ecological services provided by our forests may be summed et up as follows: l Production of oxygen: The trees produce oxygen by photo- synthesis which is so vital for life on this earth. They are rightly called as earth’s lungs. l Reducing global warming: The main greenhouse gas car- bon dioxide (CO2) is absorbed by the forests as a raw material for photosynthesis. Thus forest canopy acts as a sink for CO2 thereby reducing the problem of global warming caused by greenhouse gas CO2. Downloaded From : www.EasyEngineering.net  Downloaded From : www.EasyEngineering.net Natural Resources 7 l Wild life habitat: Forests are the homes of millions of wild animals and plants. About 7 million species are found in the tropical forests alone. l Regulation of hydrological cycle: Forested watersheds act like giant sponges, absorbing the rainfall, slowing down the runoff and slowly releasing the water for recharge of springs. About 50-80 %of the moisture in the air above tropical forests comes from their transpiration which helps in bringing rains. l Soil Conservation: Forests bind the soil particles tightly in ww l their roots and prevent soil erosion. They also act as wind- breaks. Pollution moderators: Forests can absorb many toxic gases w.E and can help in keeping the air pure. They have also been reported to absorb noise and thus help in preventing air and noise pollution. asy n OVER EXPLOITATION OF FORESTS En Since time immemorial, humans have depended heavily on forests for food, medicine, shelter, wood and fuel. With growing civilization the gin demands for raw material like timber, pulp, minerals, fuel wood etc. shooted up resulting in large scale logging, mining, road-building and ee clearing of forests. Our forests contribute substantially to the national economy. The international timber trade alone is worth over US $ 40 rin billion per year. Excessive use of fuel wood and charcoal, expansion of urban, agricultural and industrial areas and overgrazing have together g.n led to over-exploitation of our forests leading to their rapid degrada- tion. n DEFORESTATION et The total forest area of the world in 1900 was estimated to be 7,000 million hectares which was reduced to 2890 million ha in 1975 and fell down to just 2,300 million ha by 2000. Deforestation rate is relatively less in temperate countries, but it is very alarming in tropical countries where it is as high as 40-50 percent and at the present rate it is esti- mated that in the next 60 years we would lose more than 90 percent of our tropical forests. The forested area in India seems to have stabilized since 1982 with about 0.04% decline annually between 1982-90. FAO (1983) estimated that about 1.44 m ha of land was brought under afforestation during this period leading to stabilization. As per FAO estimates, the Downloaded From : www.EasyEngineering.net  Downloaded From : www.EasyEngineering.net 8 Environmental Science and Engineering deforestation rate per unit population in India is the lowest amongst the major tropical countries, despite the fact that we have a huge population size and very low per capita forest area (0.075 ha per capita). However, we are still far behind the target of achieving 33% forest area, as per our National Forest Policy, as we are still having only 19.27 % of our land area (63.38m ha) covered by forests based on satellite data (MoEF, 1998) Major Causes of Deforestation (i) Shifting cultivation: There are an estimated 300 million ww people living as shifting cultivators who practice slash and burn agriculture and are supposed to clear more than 5 lakh ha of forests for shifting cultivation annually. In India, we have this practice in North- w.EEast and to some extent in Andhra Pradesh, Bihar and M.P which contribute to nearly half of the forest clearing annually. (ii) Fuel requirements: Increasing demands for fuel wood by the asy growing population in India alone has shooted up to 300-500 million tons in 2001 as compared to just 65 million tons during independence, En thereby increasing the pressure on forests. (iii) Raw materials for industrial use: Wood for making boxes, gin furniture, railway-sleepers, plywood, match-boxes, pulp for paper in- dustry etc. have exerted tremendous pressure on forests. Plywood is in great demand for packing tea for Tea industry of Assam while fir tree ee wood is exploited greatly for packing apples in J&K. rin (iv) Development projects: Massive destruction of forests occur for various development projects like hydroelectric projects, big dams, road construction, mining etc. g.n (v) Growing food needs: In developing countries this is the main reason for deforestation. To meet the demands of rapidly growing by clearing forests. et population, agricultural lands and settlements are created permanently (vi) Overgrazing: The poor in the tropics mainly rely on wood as a source of fuel leading to loss of tree cover and the cleared lands are turned into the grazing lands. Overgrazing by the cattle leads to fur- ther degradation of these lands. Major Consequences of Deforestation Deforestation has far reaching consequences, which may be outlined as follows: (i) It threatens the existence of many wild life species due to destruction of their natural habitat. Downloaded From : www.EasyEngineering.net  Downloaded From : www.EasyEngineering.net Natural Resources 9 (ii) Biodiversity is lost and along with that genetic diversity is eroded. (iii) Hydrological cycle gets affected, thereby influencing rainfall. (iv) Problems of soil erosion and loss of soil fertility increase. (v) In hilly areas it often leads to landslides. CASE STUDIES l Desertification in hilly regions of the Himalayas Deforestation in Himalayas, involving clearance of natural for- ww ests and plantation of monocultures like Pinus roxburghi, Euca- lyptus camadulensis etc. have upset the ecosystem by changing w.E various soil (edaphic) and biological properties. Nutrient cy- cling has become poor, original rich germplasm is lost and the area is invaded by exotic weeds. These areas are not able to asy recover and are losing their fertility. The entire west Khasi hill district of Meghalaya in North-east Himalayas, Ladakh and parts of Kumaon and Garhwal are now facing the serious prob- En lem of desertification. gin Disappearing Tea gardens in Chhota Nagpur ee l This hilly region used to be a good forested area towards the rin turn of the century and used to receive fairly frequent after- noon showers favouring tea plantations. Following the destruc- g.n tion of forests, rainfall declined in Chhota Nagpur to such an extent that tea -gardens also disappeared from the region. l Waning Rainfall in Udhagamandalam (Ooty) et The sub normal rainfall during 1965-84 at Ooty in Nilgiri moun- tains has been found to be closely associated with declining forest cover in this region in the past 20 years. The rainfall pat- tern was found to fluctuate with wooded land area in the hills. When the Nilgiri mountains had luxuriant forest cover annual rainfall used to be much higher. Downloaded From : www.EasyEngineering.net  Downloaded From : www.EasyEngineering.net 10 Environmental Science and Engineering Major Activities in Forests Timber Extraction: Logging for valuable timber, such as teak and Mahogany not only involves a few large trees per hectare but about a dozen more trees since they are strongly interlocked with each other by vines etc. Also road construction for making approach to the trees causes further damage to the forests. Mining: Mining operations for extracting minerals and fossil fuels like coal often involves vast forest areas. Mining from shallow deposits is done by surface mining while that from deep deposits is done by sub-surface mining. More than 80,000 ha of land of the country is ww presently under the stress of mining activities. Mining and its associated activities require removal of vegetation along with underlying soil w.Emantle and overlying rock masses. This results in defacing the topography and destruction of the landscape in the area. Large scale deforestation has been reported in Mussorie and asy Dehradun valley due to indiscriminate mining of various minerals over a length of about 40 Km. The forested area has declined at an average rate of 33% and the increase in non-forest area due to mining activities En has resulted in relatively unstable zones leading to landslides. Indiscriminate mining in forests of Goa since 1961 has destroyed gin more than 50,000 ha of forest land. Coal mining in Jharia, Raniganj and Singrauli areas have caused extensive deforestation in Jharkhand. ee Mining of magnesite and soap- stones have destroyed 14 ha of forest in the hill slopes at Khirakot, Kosi valley, Almora. Mining of radioactive rin minerals in Kerala, Tamilnadu and Karnataka are posing similar threats of deforestation. The rich forests of Western Ghats are also facing the g.n same threat due to mining projects for excavation of copper, chromite, bauxite and magnetite. n DAMS AND THEIR EFFECTS ON FORESTS AND PEOPLE Big dams and river valley projects have multi-purpose uses and have et been referred to as “Temples of modern India”. However, these dams are also responsible for the destruction of vast areas of forests. India has more than 1550 large dams, the maximum being in the state of Maharashtra (more then 600), followed by Gujarat (more then 250) and Madhya Pradesh (130). The highest one is Tehri dam, on river Bhagirathi in Uttaranchal and the largest in terms of capacity is Bhakra dam on river Satluj in H.P. Big dams have been in sharp focus of various environmental groups all over the world which is mainly because of several ecological problems including deforestation and socio-economic problems related to tribal or native people associated with them. The Downloaded From : www.EasyEngineering.net  Downloaded From : www.EasyEngineering.net Natural Resources 11 Silent Valley hydroelectric project was one of the first such projects situated in the tropical rain forest area of Western Ghats which attracted much concern of the people. The crusade against the ecological damage and deforestation caused due to Tehri dam was led by Sh. Sunder lal Bahuguna, the leader of Chipko movement. The cause of Sardar Sarovar Dam related issues has been taken up by the environmental activists Medha Patekar, joined by Arundhati Ray and Baba Amte. For building big dams, large scale devastation of forests takes place which breaks the natural ecological balance of the region. Floods, droughts and landslides become more prevalent in such areas. Forests ww are the repositories of invaluable gifts of nature in the form of biodiversity and by destroying them ( particularly, the tropical rain for- ests) we are going to lose these species even before knowing them. These w.Especies could be having marvelous economic or medicinal value and deforestation results in loss of this storehouse of species which have evolved over millions of years in a single stroke. asy Sardar Sarovar Dam (Uprooted Forests And Tribals): A case study En The dam is situated on river Narmada and is spread over three gin states of Gujarat, Maharashtra and Madhya Pradesh. Although the project is aimed at providing irrigation water, drinking water ee and electricity to the three states, the environmental impacts of the project have raised challenging questions. rin A total of 1,44,731 ha of land will be submerged by the dam, out of which 56,547 ha is forest land. A total of 573 villages are to be submerged by the Narmada Dam. Submergence of about 40,000 ha of forest under Narmada Sagar, g.n 13,800 ha under Sardar Sarovar and 2,500 ha under Omkareshwar would further create pressure on remaining forest areas in et adjoining areas. Submergence area is very rich in wildlife e.g. tigers, panthers, bears, wolves, pangolins, hyenas, jackals, flying squirrels, antelopes, black bucks, chinkara, marsh crocodiles, turtles etc. Many of these species are listed in schedule I & II of Wildlife Protection Act, 1972. Thus massive loss of these wildlife species is apprehended due to the devastation of the forest under the project. As per the estimates of the Institute of Urban Affairs, New Delhi, the Narmada valley project will lead to eventual displacement of more than one million people, which is probably the largest (Contd.) Downloaded From : www.EasyEngineering.net  Downloaded From : www.EasyEngineering.net 12 Environmental Science and Engineering rehabilitation issue ever encountered as per the World Bank. Uprooting of the tribals and their forced shifting in far-flung areas may not be easily adjusted to. Besides serious economic deprivation, the displacement will affect the tribal peoples’ culture, their beliefs, myths and rituals, festivals, songs and dances, all closely associated with the hills, forest and streams. Most of these tribals belong to poor, unprivileged schedule castes and tribes who are being uprooted from a place where they have lived for generations. The displaced persons have to undergo hardship and distress for the sake of development and prosperity of a larger ww section of the society. It is therefore the duty of the project proponents and government to pay maximum attention for proper rehabilitation of the displaced tribals. w.E asy En gin ee rin g.n et Downloaded From : www.EasyEngineering.net  Downloaded From : www.EasyEngineering.net Natural Resources 13 2.2 WATER RESOURCES Water is an indispensable natural resource on this earth on which all life depends. About 97% of the earth’s surface is covered by water and most of the animals and plants have 60-65% water in their body. Water is characterized by certain unique features which make it a marvellous resource: (i) It exists as a liquid over a wide range of temperature i.e. from 0° to100°C. ww (ii) It has the highest specific heat, due to which it warms up and cools down very slowly without causing shocks of tempera- ture jerks to the aquatic life. w.E (iii) It has a high latent heat of vaporization Hence, it takes a huge amount of energy for getting vaporized. That’s why it produces asy a cooling effect as it evaporates. (iv) It is an excellent solvent for several nutrients. Thus, it can serve as a very good carrier of nutrients, including oxygen, which En are essential for life. But, it can also easily dissolve various pollutants and become a carrier of pathogenic microorganisms. gin (v) Due to high surface tension and cohesion it can easily rise through great heights through the trunk even in the tallest of ee the trees like Sequoia. rin (vi) It has an anamolous expansion behaviour i.e. as it freezes, it expands instead of contracting and thus becomes lighter. It is g.n because of this property that even in extreme cold, the lakes freeze only on the surface. Being lighter the ice keeps floating, whereas the bottom waters remain at a higher temperature et and therefore, can sustain aquatic organisms even in extreme cold. The water we use keeps on cycling endlessly through the environment, which we call as Hydrological Cycle. We have enormous resources of water on the earth amounting to about 1404 million Km3. The water from various moist surfaces evaporates and falls again on the earth in the form of rain or snow and passes through living organisms and ultimately returns to the oceans. Every year about 1.4 inch thick layer of water evaporates from the oceans, more than 90% of which returns to the oceans through the hydrological cycle. Solar energy drives the water cycle by evaporating it from various water bodies, which Downloaded From : www.EasyEngineering.net  Downloaded From : www.EasyEngineering.net 14 Environmental Science and Engineering subsequently return through rainfall or snow. Plants too play a very important role by absorbing the groundwater from the soil and releasing it into the atmosphere by the process of transpiration. Global distribution of water resources is quite uneven depending upon several geographic factors. Tropical rain forest areas receive maximum rainfall while the major world deserts occur in zones of dry, descending air (20-40° N and S) and receive very little rainfall. n WATER USE AND OVER-EXPLOITATION ww Due to its unique properties water is of multiple uses for all living organisms. Water is absolutely essential for life. Most of the life processes take place in water contained in the body. Uptake of nutrients, their w.Edistribution in the body, regulation of temperature, and removal of wastes are all mediated through water. Human beings depend on water for almost every developmental asy activity. Water is used for drinking, irrigation, transportation, washing and waste disposal for industries and used as a coolant for thermal En power plants. Water shapes the earth’s surface and regulates our climate. Water use by humans is of two types: water withdrawal: taking gin water from groundwater or surface water resource and water consumption: the water which is taken up but not returned for reuse. Globally, only about 60 percent of the water withdrawn is consumed ee due to loss through evaporation. rin With increasing human population and rapid development, the world water withdrawal demands have increased many folds and a large proportion of the water withdrawn is polluted due to anthropogenic g.n activities. On a global average 70 percent of the water withdrawn is while in a country like Kuwait, which is water-poor, only 4% is used et used for agriculture. In India, we use 93% of water in agricultural sector for watering the crops. About 25% of water on global average is used in industry, which again varies from a high of 70% in European countries to as low as 5% in less developed countries. Per capita use of water shows wide variations. In USA, an average family of 4 consumes more than 1000 M3 of water per year, which is many times more than that in most developing countries. Water: A Precious Natural Resource Although water is very abundant on this earth, yet it is very precious. Out of the total water reserves of the world, about 97% is salty water Downloaded From : www.EasyEngineering.net  Downloaded From : www.EasyEngineering.net Natural Resources 15 (marine) and only 3% is fresh water. Even this small fraction of fresh water is not available to us as most of it is locked up in polar ice caps and just 0.003% is readily available to us in the form of groundwater and surface water. Overuse of groundwater for drinking, irrigation and domestic pur- poses has resulted in rapid depletion of groundwater in various regions leading to lowering of water table and drying of wells. Pollution of many of the groundwater aquifers has made many of these wells unfit for consumption. Rivers and streams have long been used for discharging the ww wastes. Most of the civilizations have grown and flourished on the banks of rivers, but unfortunately, growth in turn, has been responsible for w.Epollution of the rivers. As per the United Nations estimates (2002), at least 101 billion people do not even have access to safe drinking water and 2.4 billion asy do not have adequate sanitation facilities. Increasing population and expanding development would further increase the demands for wastes. It is estimated that by 2024, two-thirds of the world population would En be suffering from acute water shortage. Groundwater gin About 9.86% of the total fresh water resources is in the form of ee groundwater and it is about 35-50 times that of surface water supplies. Till some time back groundwater was considered to be very pure. rin However, of late, even groundwater aquifers have been found to be contaminated by leachates from sanitary landfills etc. g.n A layer of sediment or rock that is highly permeable and contains water is called an aquifer. Layers of sand and gravel are good aquifers low permeability. Aquifers may be of two types: Unconfined aquifers which are overlaid by permeable earth et while clay and crystalline rocks (like granite) are not since they have materials and they are recharged by water seeping down from above in the form of rainfall and snow melt. Confined aquifers which are sandwitched between two impermeable layers of rock or sediments and are recharged only in those areas where the aquifer intersects the land surface. Sometimes the recharged area is hundreds of kilometers away from the location of the well. Fig 2.2.1 shows the groundwater system. Groundwater is not static, it moves, though at a very slow rate of about a meter or so in a year. Downloaded From : www.EasyEngineering.net  Downloaded From : www.EasyEngineering.net 16 Environmental Science and Engineering Unconfined aquifer recharge area Evapo-transpiration Precipitation from croplands Evaporation Evaporation from stream from lake Confined aquifer recharge area Infiltration Permeable ww Infiltration rock Unconfined aquifer w.E Less permeable Impermeable (Water table) Confined aquifer asy material rock layer Fig. 2.2.1. The groundwater system. An unconfined aquifer (water table) is formed when water collects over a rock or En compact clay. A confined aquifer is formed sandwitched between two layers having very low permeability. gin Effects of Groundwater Usage (i) Subsidence: When groundwater withdrawal is more than its ee recharge rate, the sediments in the aquifer get compacted, a phenomenon known as ground subsidence. Huge economic losses may occur due to this phenomenon because it results in rin the sinking of overlying land surface. The common problems associated with it include structural damage in buildings, fracture in pipes, reversing the flow of sewers and canals and g.n tidal flooding. (ii) Lowering of water table: Mining of groundwater is done extensively in arid and semi-arid regions for irrigating crop et fields. However, it is not advisable to do excessive mining as it would cause a sharp decline in future agricultural production, due to lowering of water table. (iii) Water logging: When excessive irrigation is done with brackish water it raises the water table gradually leading to water-logging and salinity problems. Downloaded From : www.EasyEngineering.net  Downloaded From : www.EasyEngineering.net Natural Resources 17 Surface Water The water coming through precipitation (rainfall, snow) when does not percolate down into the ground or does not return to the atmos- phere as evaporation or transpiration loss, assumes the form of streams, lakes, ponds, wetlands or artificial reservoirs known as surface water. The surface water is largely used for irrigation, industrial use, public water supply, navigation etc. A country’s economy is largely depend- ent upon its rivers. Water rich vs. Water poor countries ww The top ten water rich countries are Iceland, Surinam, Guyana, Papua New Guinea, Gabon, Solomon Islands, Canada, Norway, w.E Panama, and Brazil lying in the far north and have low evaporation losses. The water poor countries include Kuwait, Egypt, United Arab asy Emirates, Malta, Jordon, Saudi Arabia, Singapore, Maldovia, Israel and Oman, lying in the desert belt at about 15° to 25° Latitude and some of them like Malta and Singapore are densely En populated areas resulting in low per capita water. n FLOODS gin ee In some countries like India and Bangladesh rainfall does not occur throughout the year, rather, 90% of it is concentrated into a few months rin (June-September). Heavy rainfall often causes floods in the low-lying coastal areas. Prolonged downpour can also cause the over-flowing of lakes and rivers resulting into floods. g.n Deforestation, overgrazing, mining, rapid industrialization, global of floods, which otherwise is a natural disaster. Floods have been regular features of some parts of India and et warming etc. have also contributed largely to a sharp rise in the incidence Bangladesh causing huge economic loss as well as loss of life. People of Bangladesh are accustomed to moderate flooding during monsoon and they utilize the flood water for raising paddy. But, severe floods like that in 1970, 1988 and 1991 resulting from excessive Himalayan runoff and storms, had very disastrous consequences causing massive deaths and damages. In 1970, about one million people were drowned while 1,40,000 people died in 1991. Networking of rivers is being proposed at national level to deal with the problems of floods. Downloaded From : www.EasyEngineering.net  Downloaded From : www.EasyEngineering.net 18 Environmental Science and Engineering n DROUGHTS There are about 80 countries in the world, lying in the arid and semi- arid regions that experience frequent spells of droughts, very often extending up to year long duration. When annual rainfall is below normal and less than evaporation, drought conditions are created. Ironically, these drought- hit areas are often having a high population growth which leads to poor land use and makes the situation worse. Anthropogenic causes: Drought is a meteorological phenomenon, but due to several anthropogenic causes like over grazing, deforestation, mining etc. there is spreading of the deserts tending to ww convert more areas to drought affected areas. In the last twenty years, India has experienced more and more desertification, thereby increasing w.Ethe vulnerability of larger parts of the country to droughts. Erroneous and intensive cropping patter n and increased exploitation of scarce water resources through well or canal irrigation asy to get high productivity has converted drought - prone areas into desertified ones. In Maharashtra there has been no recovery from drought for the last 30 years due to over-exploitation of water by En sugarcane crop which has high water demands. Remedial measures: Indigenous knowledge in control of drought gin and desertification can be very useful for dealing with the problem. Carefully selected mixed cropping help optimize production and ee minimize the risks of crop failures. Social Forestry and Wasteland development can prove quite effective to fight the problem, but it should rin be based on proper understanding of ecological requirements and natural process, otherwise it may even boomrang. The Kolar district of g.n Karnataka is one of the leaders in Social Forestry with World Bank Aid, but all its 11 talukas suffer from drought. It is because the tree the water table because of its very high transpiration rate. n CONFLICTS OVER WATER et used for plantation here was Eucalyptus which is now known to lower Indispensability of water and its unequal distribution has often led to inter-state or international disputes. Issues related to sharing of river water have been largely affecting our farmers and also shaking our governments. Some major water conflicts are discussed here. l Water conflict in the Middle East: Three river basins, namely the Jordan, the Tigris-Euphrates and the Nile are the shared water resources for Middle East countries. Ethiopia controls the head waters of 80% of Nile’s flow and plans to increase it. Downloaded From : www.EasyEngineering.net  Downloaded From : www.EasyEngineering.net Natural Resources 19 Sudan too is trying to divert more water. This would badly affect Egypt, which is a desert, except for a thin strip of irrigated cropland along the river Nile and its delta. The population of Egypt is likely to double in the next 20 years, thereby increasing its water crisis. Likewise there is a fierce battle for water among Jordan, Syria and Israel for the Jordan River water share. Turkey has abundant water and plans to build 22 dams on Tigris-Euphrates for Hydroelectric power generation. But, it would drastically reduce the flow of water to Syria and Iraq, ww lying downstream. Turkey dreams to become the region’s water Super power. It plans to transport and sell water to starved Saudi Arabia, Kuwait, Syria, Israel and Jordan. w.E Probably, the next war in the Middle East would be fought over water and not oil. l asy The Indus Water Treaty: The Indus, one of the mightiest rivers is dying a slow death due to dams and barrages that have been built higher up on the river. The Sukkur barrage En (1932), Ghulam Mohamad Barrage at Kotri (1958) and Tarbela and Chasma Dams on Jhelum, a tributary of Indus gin have resulted in severe shrinking of the Indus delta. In 1960, the Indus water treaty was established vide which Indus, the Jhelum and the Chenab were allocated to Pakistan and the ee Satluj, the Ravi and the Beas were allocated to India. Being rin the riparian state, India has pre-emptive right to construct barrages across all these rivers in Indian territory. However, g.n the treaty requires that the three rivers allocated to Pakistan may be used for non-consumptive purposes by India i.e. without changing its flow and quality. With improving political et relations between the two countries it is desirable to work out techno-economic details and go for an integrated development of the river basin in a sustainable manner. l The Cauvery water dispute: Out of India’s 18 major rivers, 17 are shared between different states. In all these cases, there are intense conflicts over these resources which hardly seem to resolve. The Cauvery river water is a bone of contention between Tamilnadu and Karnataka and the fighting is almost hundred years old. Tamilnadu, occupying the downstream region of the river wants water-use regulated in the upstream. Whereas, the upstream state Karnataka refuses to do so and claims its primacy over the river as upstream user. The river Downloaded From : www.EasyEngineering.net  Downloaded From : www.EasyEngineering.net 20 Environmental Science and Engineering water is almost fully utilized and both the states have increasing demands for agriculture and industry. The consumption is more in Tamilnadu than Karnataka where the catchment area is more rocky. On June 2,1990, the Cauvery Water Dispute Tribunal was set up which through an interim award directed Karnataka to ensure that 205 TMCF of water was made available in Tamil Nadu’s Mettur dam every year, till a settlement was reached. In 1991-92 due to good monsoon, there was no dispute due to good stock of water in Mettur, but in 1995, the situation turned into a crisis due to delayed ww rains and an expert Committee was set up to look into the matter which found that there was a complex cropping pattern in Cauvery basin. Sambra paddy in winter, Kurvai paddy in w.E summer and some cash crops demanded intensive water, thus aggravating the water crisis. Proper selection of crop varieties, optimum use of water, better rationing, rational sharing asy patterns, and pricing of water are suggested as some measures to solve the problem. l En The Satluj-Yamuna link (SYL) canal dispute: The issue of sharing the Ravi-Beas waters and SYL issue between Punjab gin and Haryana is being discussed time and again and the case is in the Supreme Court. The Eradi Tribunal (1985) based the allocation of water on the basis of the time-inflow data of 20 ee years (1960-80), according to which 17.17 MAF (million acre feet) water was available. However, now it is argued by Punjab rin that in the last 17 years there has been consistent decline reducing the quantity to 14.34 MAF. The Supreme Court on g.n January 15, 2002 directed Punjab to complete and commission the SYL within a year, failing which the Center was told to et complete it. However, two years have passed, but neither the SYL has been completed nor the conflict over sharing of Ravi- Beas water is resolved. The conflict is that Punjab being the riparian state for Beas, Ravi and Satluj stakes its claim, Haryana has faced acute shortage of water after it became a state in 1966 and has been trying to help it out by signing an MOU (Memorandum of understanding) with UP, Rajasthan and Delhi for allocation of Yamuna waters. The Yamuna basin covers the state of Haryana while the Indus basin covers Punjab. The conflict revolving around sharing of river water needs to be tackled with greater understanding and objectivity. Downloaded From : www.EasyEngineering.net  Downloaded From : www.EasyEngineering.net Natural Resources 21 Traditional Water Management System In India, even today, there are several villages where water management is done not by the Irrigation Department, but by local managers. In south India, a neerkatti manages the traditional tanks very efficiently based on his/her knowledge of the terrain, drainage and irrigation needs. They usually give preference to the tail end fields and decide per capita allocation of water based on the stock of available water in the tank and crop needs. In Maharashtra, the water mangers are called havaldars or jaghyas who manage and resolve conflicts by overseeing the water channels from main canal to the distributory canals. In ww Ladakh, the water manager is known as churpun who has got complete charge with full powers over allocation of available water. The major source of water is melt water from glaciers and snow supplementary w.Eby water from springs and marshes. The water is distributed to different fields through an intricate network of earthen channels. asy In traditional water management, innovative arrangements ensure equitable distribution of water, which are democratically implemented. The ‘gram-sabhas’ approve these plans publicly. While water disputes En between states and nations often assume battle like situations, our traditional water managers in villages prove to be quite effective. gin n BIG DAMS- BENEFITS AND PROBLEMS Benefits ee rin River valley projects with big dams have usually been considered to play a key role in the development process due to their multiple uses. India has the distinction of having the largest number of river-valley projects. These dams are often regarded as a symbol of national g.n development. The tribals living in the area pin big hopes on these et projects as they aim at providing employment and raising the standard and quality of life. The dams have tremendous potential for economic upliftment and growth. They can help in checking floods and famines, generate electricity and reduce water and power shortage, provide irrigation water to lower areas, provide drinking water in remote areas and promote navigation, fishery etc. Environmental Problems The environmental impacts of big-dams are also too many due to which very often the big dams become a subject of controversy. The impacts can be at the upstream as well as downstream levels. Downloaded From : www.EasyEngineering.net  Downloaded From : www.EasyEngineering.net 22 Environmental Science and Engineering (A) The upstream problems include the following: (i) Displacement of tribal people (ii) Loss of forests, flora and fauna (iii) Changes in fisheries and the spawning grounds (iv) Siltation and sedimentation of reservoirs (v) Loss of non-forest land (vi) Stagnation and waterlogging near reservoir (vii) Breeding of vectors and spread of vector-borne diseases (viii) Reservoir induced seismicity (RIS) causing earthquakes ww (ix) Growth of aquatic weeds. (x) Microclimatic changes. w.E(B) The downstream impacts include the following: (i) Water logging and salinity due to over irrigation (ii) Micro-climatic changes asy (iii) Reduced water flow and silt deposition in river (iv) Flash floods En (v) Salt water intrusion at river mouth (vi) Loss of land fertility along the river since the sediments carry- gin ing nutrients get deposited in the reservoir (vii) Outbreak of vector-borne diseases like malaria ee Thus, although dams are built to serve the society with multiple uses, but it has several serious side-effects. That is why now there is a rin shift towards construction of small dams or mini-hydel projects. g.n et Downloaded From : www.EasyEngineering.net  Downloaded From : www.EasyEngineering.net Natural Resources 23 2.3 MINERAL RESOURCES Minerals are naturally occurring, inorganic, crystalline solids having a definite chemical composition and characteristic physical properties. There are thousands of minerals occurring in different parts of the world. However, most of the rocks, we see everyday are just composed of a few common minerals like quartz, feldspar, biotite, dolomite, calcite, laterite etc. These minerals, in turn, are composed of some elements ww like silicon, oxygen, iron, magnesium, calcium, aluminium etc. n USES AND EXPLOITATION w.EMinerals find use in a large number of ways in everyday use in domestic, agricultural, industrial and commercial sectors and thus form a very important part of any nation’s economy. The main uses of minerals are as follows: asy (i) Development of industrial plants and machinery. En (ii) Generation of energy e.g. coal, lignite, uranium. (iii) Construction, housing, settlements. gin (iv) Defence equipments-weapons, armaments. (v) Transportation means. ee (vi) Communication- telephone wires, cables, electronic devices. rin (vii) Medicinal system- particularly in Ayurvedic System. (viii) Formation of alloys for various purposes (e.g. phosphorite). g.n (ix) Agriculture–as fertilizers, seed dressings and fungicides (e.g. zineb containing zinc, Maneb-containing manganese etc.). (x) Jewellery–e.g. Gold, silver, platinum, diamond. et Based on their properties, minerals are basically of two types: (i) Non metallic minerals e.g. graphite, diamond, quartz, feldspar. (ii) Metallic minerals e.g. Bauxite, laterite, haematite etc. Use of metals by human beings has been so extensive since the very beginning of human civilization that two of the major epochs of human history are named after them as Bronze Age and Iron Age. The reserves of metals and the technical know-how to extract them have been the key elements in determining the economy and political power of nations. Out of the various metals, the one used in maximum quantity is Iron and steel (740 million metric tons annually) followed by manganese, copper, chromium, aluminium and Nickel. Downloaded From : www.EasyEngineering.net  Downloaded From : www.EasyEngineering.net 24 Environmental Science and Engineering Distribution and uses of some of the major metallic and non- metallic minerals are given in Tables 2.3.1 and 2.3.2. Table 2.3.1. Major reserves and important uses of some of the major metals Metal Major World Reserves Major Uses Aluminium Australia, Guinea, Packaging food items, transpor- Jamaica tation, utensils, electronics Chromium CIS, South Africa For making high strength steel ww Copper U.S.A., Canada, CIS, alloys, In textile/tanning industries Electric and electronic goods, w.E Iron Chile, Zambia CIS, South America, building, construction, vessels Heavy machinery, steel produc- Lead asy Canada, U.S.A. North America, U.S.A., tion transportation means Leaded gasoline, Car batteries, Manganese CIS En South Africa, CIS, paints, ammunition For making high strength, heat- Platinum gin Brazil, Gabon South Africa, CIS resistant steel alloys Use in automobiles, catalytic group Gold South Canada ee Africa, CIS, converters, electronics, medical uses. rin Ornaments, medical use, elec- tronic use, use in aerospace Silver Canada, South Africa, Mexico g.n Photography, electronics jewellery Nickel CIS, Canada, New Caledonia et Chemical industry, steel alloys Table 2.3.2. Major uses of some non-metallic minerals Non-metal Mineral Major Uses Silicate minerals Sand and gravel for construction, bricks, paving etc. Limestone Used for concrete, building stone, used in agriculture for neutralizing acid soils, used in cement industry Gypsum Used in plaster wall-board, in agriculture Potash, phosphorite Used as fertilizers Sulphur pyrites Used in medicine, car battery, industry. Downloaded From : www.EasyEngineering.net  Downloaded From : www.EasyEngineering.net Natural Resources 25 It is evident from the Tables that the CIS countries (The Com- monwealth of Independent States i.e. 12 repubics of former USSR), the United States of America, Canada, South Africa and Australia are having the major world reserves of most of the metallic minerals. Due to huge mineral and energy resources, the USA became the richest and the most powerful nation in the world in even less than 200 years. Ja- pan too needs a mention here, as there are virtually no metal reserves, coal, oil and timber resources in Japan and it is totally dependent on other countries for its resources. But, it has developed energy efficient technologies to upgrade these resources to high quality finished prod- ww ucts to sustain its economy. Minerals are sometimes classified as Critical and Strategic. Critical minerals are essential for the economy of a nation e.g. w.Eiron, aluminium, copper, gold etc. Strategic minerals are those required for the defence of a country asy e.g. Manganese, cobalt, platinum, chromium etc. Some Major Minerals of India En (a) Energy generating minerals Coal and lignite: West Bengal, Jharkhand, Orissa, M.P., A.P. gin Uranium (Pitchblende or Uranite ore): Jharkhand, Andhra Pradesh (Nellore, Nalgonda), Meghalaya, Rajasthan (Ajmer). ee (b) Other commercially used minerals Aluminium (Bauxite ore): Jharkhand, West Bengal, Maharashtra, M.P., Tamilnadu. rin A.P., Tamilnadu, Karnataka, Maharashtra and Goa. g.n Iron (haematite and magnetite ore): Jharkhand, Orissa, M.P., Copper (Copper Pyrites): Rajasthan (Khetri), Bihar, Jharkhand, Karnataka, M.P., West Bengal, Andhra Pradesh and Uttaranchal. et n ENVIRONMENTAL IMPACTS OF MINERAL EXTRACTION AND USE The issue related to the limits of the mineral resources in our earth’s crust or in the ocean is not so significant. More important environ- mental concern arises from the impacts of extraction and processing of these minerals during mining, smelting etc. Indian Scenario: India is the producer of 84 minerals the annual value of which is about Rs. 50,000 crore. At least six major mines need a mention here which are known for causing severe problems: Downloaded From : www.EasyEngineering.net  Downloaded From : www.EasyEngineering.net 26 Environmental Science and Engineering (i) Jaduguda Uranium Mine, Jharkhand—exposing local people to radioactive hazards. (ii) Jharia coal mines, Jharkhand—underground fire leading to land subsidence and forced displacement of people. (iii) Sukinda chromite mines, Orissa—seeping of hexavalent chromium into river posing serious health hazard, Cr6+ being highly toxic and carcinogenic. (iv) Kudremukh iron ore mine, Karnataka—causing river pollution and threat to biodiversity. (v) East coast Bauxite mine, Orissa—Land encroachment and ww issue of rehabilitation unsettled. (vi) North-Eastern Coal Fields, Assam—Very high sulphur w.E contamination of groundwater. Impacts of mining: Mining is done to extract minerals (or fossil fuels) from deep deposits in soil by using sub-surface mining or from asy shallow deposits by surface mining. The former method is more destructive, dangerous and expensive including risks of occupational En hazards and accidents. Surface mining can make use of any of the following three types: gin (a) Open-pit mining in which machines dig holes and remove the ores (e.g. copper, iron, gravel, limestone, sandstone, marble, granite). ee (b) Dredging in which chained buckets and draglines are used rin which scrap up the minerals from under-water mineral deposits. g.n (c) Strip mining in which the ore is stripped off by using bulldozers, power shovels and stripping wheels (e.g. phosphate rocks). The environmental damage caused by mining activities are as follows: et (i) Devegetation and defacing of landscape: The topsoil as well as the vegetation are removed from the mining area to get access to the deposit. While large scale deforestation or devegetation leads to several ecological losses as already discussed in the previous section, the landscape also gets badly affected. The huge quantities of debris and tailings alongwith big scars and disruptions spoil the aesthetic value of the region and make it prone to soil erosion. (ii) Subsidence of land: This is mainly associated with underground mining. Subsidence of mining areas often results in tilting of buildings, cracks in houses, buckling of roads, Downloaded From : www.EasyEngineering.net  Downloaded From : www.EasyEngineering.net Natural Resources 27 bending of rail tracks and leaking of gas from cracked pipe- lines leading to serious disasters. (iii) Groundwater contamination: Mining disturbs the natural hydrological processes and also pollutes the groundwater. Sulphur, usually present as an impurity in many ores is known to get converted into sulphuric acid through microbial action, thereby making the water acidic. Some heavy metals also get leached into the groundwater and contaminate it posing health hazards. (iv) Surface water pollution: The acid mine drainage often con- ww taminates the nearby streams and lakes. The acidic water is detrimental to many forms of aquatic life. Sometimes radio- active substances like uranium also contaminate the water w.E bodies through mine wastes and kill aquatic animals. Heavy metal pollution of water bodies near the mining areas is a common feature creating health hazards. asy (v) Air pollution: In order to separate and purify the metal from other impurities in the ore, smelting is done which emits En enormous quantities of air pollutants damaging the vegetation nearby and has serious environmental health impacts. The gin suspended particulate matter (SPM), SOx, soot, arsenic particles, cadmium, lead etc. shoot up in the atmosphere near the smelters and the public suffers from several health problems. ee rin (vi) Occupational Health Hazards: Most of the miners suffer from various respiratory and skin diseases due to constant exposure g.n to the suspended particulate matter and toxic substances. Miners working in different types of mines suffer from asbestosis, silicosis, black lung disease etc. Remedial measures: Safety of mine workers is usually not a et priority subject of industry. Statistical data show that, on an average, there are 30 non-fatal but disabling accidents per ton of mineral produced and one death per 2.5 tons of mineral produced. In order to minimize the adverse impacts of mining it is desirable to adopt eco-friendly mining technology. The low-grade ores can be better utilized by using microbial-leaching technique. The bacterium Thiobacillus ferroxidans has been successfully and economically used for extracting gold embedded in iron sulphide ore. The ores are inoculated with the desired strains of bacteria, which remove the impurities (like sulphur) and leave the pure mineral. This biological method is helpful from economic as well as environmental point of view. Downloaded From : www.EasyEngineering.net  Downloaded From : www.EasyEngineering.net 28 Environmental Science and Engineering Restoration of mined areas by re-vegetating them with appropri- ate plant species, stabilization of the mined lands, gradual restoration of flora, prevention of toxic drainage discharge and conforming to the standards of air emissions are essential for minimizing environmental impacts of mining. CASE STUDIES l Mining and quarrying in Udaipur About 200 open cast mining and quarrying centers in Udaipur, about half of which are illegal are involved in stone mining ww including soapstone, building stone, rock phosphate and dolomite. The mines spread over 15,000 hectares in Udaipur have caused w.E many adverse impacts on environment. About 150 tonnes of explosives are used per month in blasting. The overburden, washoff, discharge of mine water etc. pollute the water. The Maton mines have badly polluted the Ahar river. The hills around the asy mines are devoid of any vegetation except a few scattered patches and the hills are suffering from acute soil erosion. The waste water En flows towards a big tank of “Bag Dara”. Due to scarcity of water people are compelled to use this effluent for irrigation purpose. gin The blasting activity has adversely affected the fauna and the animals like tiger, lion, deer and even hare, fox, wild cats and birds have disappeared from the mining area. l ee Mining in Sariska Tiger Reserve in Aravallis rin The Aravalli range is spread over about 692 km in the North-west g.n India covering Gujarat, Rajasthan, Haryana and Delhi. The hill region is very rich in biodiversity as well as mineral resources. The Sariska tiger reserve has gentle slopy hills, vertical rocky et valleys, flat plains as well as deep gorges. The reserve is very rich in wild life and has enormous mineral reserves like quartzite, Schists, marble and granite in abundance. Mining operations within and around the Sariska Tiger reserve has left many areas permanently infertile and barren. The precious wild life is under serious threat. We must preserve the Aravalli series as a National Heritage and the Supreme Court on December 31st, 1991 has given a judgement in response to a Public Interest Litigation of Tarun Bharat Sangh, an NGO wherein both Centre and State Government of Rajasthan have been directed to ensure that all mining activity within the park be stopped. More than 400 mines were shut immediately. But,