AECC Unit 2 Natural Resources PDF

Natural Resources We will discuss and learn in this unit about: Natural resources: definition, concept and types Land resources Forest resources Water resources Food resources Energy resources ❖ Syllabus of this Unit as per CD is: Natural resources: Land resource...

Natural Resources We will discuss and learn in this unit about: Natural resources: definition, concept and types Land resources Forest resources Water resources Food resources Energy resources ❖ Syllabus of this Unit as per CD is: Natural resources: Land resources and land use change, land degradation, soil erosion and desertification. Deforestation: causes and impacts due to mining, dam building on environment, forests, biodiversity and tribal population. Water Resources: Use and over-exploitation of surface and groundwater, floods, drought, conflicts over water (international and inter-state). Heating of earth and circulation of air; air mass formation and precipitation. Energy resources- renewable and non-renewable energy sources, use of alternate energy sources, Growing energy needs, Case studies.  Life on the earth depends upon a large number of things and services which are provided by nature and are, thus, known as Natural Resources. Water, Air, Soil, Minerals, Coal, Forests, Crops and Wildlife. Natural resources vary in their nature, origin, availability, exhaustibility, extent, etc. Some natural resources, like air, solar energy, etc. are inexhaustible and thus can be used unlimitedly while as others exhaustible resources get consumed on being used and require judicious utilization.  Renewable resources have the capability to renew themselves if used within certain limits. All natural resources, however, demand a proper and clever use. Reckless and injudicious utilization of natural resources is bound to lead us to an era full of all sorts of crises. Reckless use not only leads to the acute shortage of resources but may also result in generation of unmanageable wastes and contamination of our environment which is a storehouse of all the resources. There must be sustainable use of natural resources in order to safeguard our own persistent survival. 3.1. Introduction: Any material which is naturally available and can be used or transformed to be used in any way by man for his well being is called a Natural Resource. Thus a natural resource is anything that we can use and which comes from nature. Air, water, sun, wood, oil, iron, and coal etc are all examples of natural resources. Natural resources, thus, must: Be naturally occurring on the earth. Useful to man in any way that is either directly in its original form or indirectly after certain modification. Accessible to man. If something very useful to man is known to occur somewhere but is out of human reach or we do not have appropriate tools and technology to extract or use it, it is not a natural resource for us. Modifiable or convertible to more useful products. It means we should have appropriate technology to make use of a natural resource.  Refined oil and hydro-electric energy are not natural resources because people make them. The earth is seemingly an inexhaustible storehouse of innumerable natural resources. Although there are vast treasures of different resources on the earth, they are not unlimited or inexhaustible. Some resources are renewable while others are not. Man has been exploiting major groups of resources including land, fossil fuels, forests, wildlife, etc. Which have now been depleted to an irreparable extent. We need to switch over to alternative and nonconventional resources in order to avoid problems associated with scarcity of resources. 3.2. Classification of Natural Resources: There are numerous natural resources required and utilized by man in his day-to-day life. There are various basis of classifying natural resources into various groups. These bases include ✓ On the basis of origin Biotic such as forest, coal, food, etc Abiotic such as water, air, land, minerals, etc ✓ On the basis of nature Organic such as coal, oil, etc Inorganic such as coal, mica, gold, etc ✓ On the basis of renewability Renewable such as forest Non-renewable such as coal  ✓ On the basis of exhaustibility Exhaustible such silver, gold, forest, oil, coal, etc Inexhaustible such as wind, solar energy, etc ✓ On the basis of tradition/convention Conventional such as oil, coal, etc. Non-conventional such as wind, tidal energy, solar energy, etc. We often hear there are two kinds of natural resources: Renewable resources and Non-renewable resources. ✓ A renewable resource grows again and comes back again after we use it. For example, soil, sunlight, water and wood are renewable resources. ✓ A non-renewable resource is a resource that does not grow and come back, or a resource that would take a very long time to come back. For example, coal is a non-renewable resource. When we use coal, there is less coal afterward. One day, there will be no more of it to make goods. The non-renewable resource can be used directly (for example, burning oil to cook), or we can find a renewable resource to use (for example, using wind energy to make electricity).  Most natural resources are limited. This means they will eventually run out. A perpetual or endless resource has a never-ending supply. Some examples of perpetual resources include solar energy, tidal energy, and wind energy. It is very important to protect and conserve our natural resources and use them in a judicious manner so that we do not exhaust them. It 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 the coming slides we ‘ll discuss some important natural resources such as forest resources, water resources, food resources, energy resources and land resources in detail 3.3. Land Resources: Land in general refers to any piece or entire of the terrestrial earth but as a natural resource it means that component of the earth which is of direct economic use for the human population living on it. In fact land is one of the most important natural resources upon which we depend for our food, fibre and fuel wood, the basic amenities of life. But this resource is not infinite. There are limited land resources available for direct human use. It is the top soil or the uppermost portion of the earth crust that actually forms useful land resource.  Land is classified as a renewable natural resource because it is continuously regenerated by natural process though at a very slow rate. But, when rate of erosion is faster than rate of renewal, the soil becomes a non- renewable resource. It is said that about 200-1000 years are needed for the formation of one inch of soil. Following are some important factors which affect or decide the value of land as a significant natural resource: Soil and terrain conditions ✓ Thus, natural resources, in the context Freshwater conditions of “land”, are taken to be those components of land units that are of Climatic conditions, and direct economic use for human Biotic(vegetation and animal life) population living in the area, or conditions expected to move into the area. The basic functions of land in supporting human and other terrestrial ecosystems are: Land is a store of wealth in its own. Land is a storehouse of minerals and raw materials for human use. Land helps in the production of food, fibre, fuel, etc. Land is the biological habitat for many plants, animals and microorganisms. Land regulates flow of surface water and stores groundwater. Land enables or hampers movement of people and animals between one place to another. Land is a buffer, filter or modifier for chemical pollutants. Land is co-determinant in the global energy balance and the global hydrological cycle, which provides both a source and sink for greenhouse gases.  Land is the physical space for settlements, industry and recreation. Land stores and protects evidence of past climates, archaeological remains from the historical or prehistorical record. 3.3.1. Texture, Structure and Composition of Soil: Soil is an uncemented aggregate of mineral grains and decayed organic matter with water and air occupying the void spaces between particles. Soil Texture: Soil texture refers to the size distribution of soil particles and the relative percentage of sand, silt and clay in a soil. Three sizes of particles are recognized in soil. These are tabulated below: The relationship between particle size and class names is: It is to be noted that a clay soil remains clay and a sandy soil remains sandy because the size of particles in the soil is not subject to ready change.  Soil texture controls the following properties of soil with respect to plant growth: aeration, availability and movement of water, content of plant nutrients, and workability. ✓ For instance, movement of water in various soil-textured types is illustrated Water drainage from various types of soils Soil Structure: Soil structure refers to the arrangement of soil particles into groups or aggregates. The peds are natural, fairly water stable aggregates; and clods are artificial, water unstable aggregates. Ploughing of wet clay soil makes the soil cloddy. Soil structure is divided into the following groups: (a) Types of soil structure. Examples: Platy, spheroidal, etc (b) Class of soil structure. Examples: Fine, medium, coarse, etc. (c) Grades of soil structure. Examples: Weak, strong, etc. Soil Composition: ✓ Four major components of soils are mineral materials, organic matter, water and air. Approximate composition of soil is given below: (i) Mineral Materials (a) Mineral materials are elements (Si, Fe, O, Mg, Al, Ca, Na and K), finely divided quartz (SiO2), iron-silicates and aluminium silicates. (b) They are derived from the underlying bedrock or from materials transported and deposited by surface run-off, wind fl ow, etc. (c) Secondary minerals (viz., Na+, K+, Ca2+, Mg2+, H+, NH+4) are held at the surface of all the silicate clays. These are not leached by water and are exchanged. Thus, they are available as plant nutrients. (ii) Organic Matter (a) Organic matter can be crop residues, weeds, grasses, bacteria, fungi, other microorganisms and animal manures. (b) They come from the residues of plants and animals. (c) Functions They provide food for microorganisms, other nutrients to plants. Thus, soil productivity is controlled by them. They provide a storehouse for nutrients. They increasing water holding capacity of soil. (iii) Water It is a good solvent for many nutrients which move into plant roots. Water is also important to maintain the proper form and position of leaves and new shoots for capturing sunlight and satisfactory growth. (iv) Air Soil air encourages optimum rate of the essential metabolic processes of various organisms. Land Resources  Land is very basic requirement of man for various types of life-related activities. As a valuable resource land is, used for: building houses, constructing roads and railways, installing industries and developing towns and cities on it. cultivating food and fodder for humans and their livestock production of raw materials for industries raising forests and other industrial woodlands damping of waste generated during domestic and industrial processes In addition, we have to conserve wilderness area in forests, grasslands, wetlands, mountains, coasts, etc. to protect our vitally valuable biodiversity. This use of land is equally important. It demands a rational use of land resources, and it can be achieved through careful planning.  Land use involves the management and modification of natural environment or wilderness into built environment such as settlements and semi-natural habitats such as arable fields, pastures, and managed woods. Land use planning refers to policy of using a portion of land strictly for the purpose it is suitable. Different types of land are classified into various categories. Each category is assigned a suitable type of use and it should be utilized for the purpose fixed for it. 3.3.2. Global Land Use Patterns: Though the earth is a vast planet with huge surface area but 71% of it is under oceans. The Earth’s total land area is 148,939,063.133 km². Out of this terrestrial surface very limited land area is effectively useful or accessible for man.  A large proportion of it is either inaccessible or unfit for any cultivation or residential uses. About 15.46% of the land occurs in the cold tundra zone, which is not easily amenable to normal agriculture. Land which is capable of being ploughed and used to grow crops is called arable land. Major categories of land include: Urban or Built-up Land Degraded Land Agricultural Land Tundra Rangeland Perennial snow or ice Forest Land Wetland Barren Land Landform Types According to Buringh (1989) 11 to 12 % of the land surface is generally suitable for food and fiber production, 24 % is used for grazing, forests occupy about 31 % and the remaining 33 % has too many constraints for most uses. Land is being put to varied types of uses worldwide. With increase in human population and advancement in the technology, more and more land had been brought under various types modifications. Now more land is required to be used for agricultural purposes to meet the growing needs of food production. With his economic developmental activities gaining momentum, man put land to various other uses including establishment of industrial areas, mining, transportation, urbanization, etc. As a result:  Agricultural lands are expanding More and more land has been brought under industrial or urban setup Forest lands, grasslands and wetlands has been cleared of their natural cover Large portions of land are rendered degraded due to overexploitation Soil is dumped with various kinds of wastes and toxic materials 3.3.3. Land Degradation: Land degradation means reduction in the quality or value of land. When land is put to extensive use or over exploitation its quality degrades. Sometimes land is put to uses which are not suitable for that piece of land. It also degrades the land. Farmland is under serious threat due to more and more intense utilization. Every year, between 5 to 7 million hectares of land worldwide is added to the existing degraded farmland. Some factors responsible for degradation of land include: Dumping of harmful wastes on land Over irrigation of farmland that leads to salinization Pollution of land due to use of fertilizers and pesticides Unsuitable land use Soil erosion and landslides Wrong agricultural practices Deforestation  Mechanisms that initiate land degradation include physical, chemical, and biological processes. ✓ Physical processes: Decline in soil structure leading to crusting, compaction, erosion, desertification, anaerobism, environmental pollution, and unsustainable use of natural resources. ✓ Chemical processes: Acidification, leaching, decrease in cation retention capacity, and fertility depletion. ✓ Biological processes: Reduction in total and biomass carbon, and decline in land biodiversity. Soil structure is an important property that affects all three degradative processes. Sustainable Land Management Land Resource Management 3.3.4. Soil Erosion: Soil erosion is the most common form of land degradation. It is the removal of outer layer of soil. It is defined as the movement of soil components, especially surface-litter and top soil from one place to another. Besides causing pollution in water bodies, soil erosion badly affects soil fertility. It is the top layer of soil that contains most nutrients and if most fertile. When this layer gets eroded it results in the loss of fertility. Almost one third of the world’s cropland is affected by soil erosion. Soil erosion is a natural process but it gets accelerated due various human activities. Deforestation, mining, overgrazing, cultivation, etc enhances the rate of soil erosion. Causes of soil erosion: Various human activities like mining, deforestation, farming, overgrazing, etc are the major causes responsible for soil erosion. Due to these processes the top soil is disturbed or rendered devoid of vegetation cover. So the land is directly exposed to the action of various physical forces facilitating erosion. Overgrazing is responsible for 35% of the world’s soil erosion while 30% of the serious soil erosion has been caused by deforestation. Unsustainable methods of farming cause 28% of soil erosion. Mechanism of soil erosion: There are two main agents which cause soil erosion. These are water and wind. Water erodes soil by washing its particles along with its flow. Wind also detaches and removes the soil particles and causes their movement from one place to another. ✓ Soil erosion caused by water is of following types: Sheet erosion: when there is uniform removal of a thin layer of soil from a large surface area, it is called sheet erosion. This is usually due to run-off water. Rill erosion: When there is rainfall and rapidly running water produces finger shaped grooves or rills over the area, it is called rill erosion. Gully erosion: It is a more prominent type of soil erosion. When the rainfall is very heavy, deeper cavities or gullies are formed on the ground. Slip erosion: This occurs due to heavy rainfall on slopes of hills and mountains.  Stream bank erosion: During the rainy season, when fast running streams take a turn in some other direction, they cut the soil and make caves in the banks. ✓ Soil erosion caused by wind is of following three types: Saltation: This occurs under the influence of direct pressure of stormy wind and the soil particles of 1-1.5 mm diameter move up in vertical direction. Suspension: Here soil particles of small size suspended in the air are kicked up and taken away to distant places. Surface creep: Here larger particles (5-10 mm diameter) creep over the soil surface along with wind. Preventing Soil Erosion Preventing soil erosion requires political, economic and technical changes. Political and economic changes need to address the possibility of incentives to encourage farmers to manage their land sustainably. ✓ Aspects of technical changes in agriculture that could substantially contribute to the prevention of soil erosion are: Use of contour ploughing and wind breaks Leaving unploughed grass strips between ploughed land Making sure that there are always plants growing on the soil, and that the soil is rich in humus (decaying plant and animal remains). This organic matter is the “glue” that binds the soil particles together and plays an important part in the prevention of erosion Avoiding overgrazing and the over-use of crop lands  Allowing indigenous plants to grow along the river banks instead of ploughing and planting crops right up to the water’s edge Encouraging biological diversity by planting several different types of plants together Conservation of wetlands. 3.3.5. Land Slides: Geologists use a variety of classification schemes to describe the causes of landslides. Because of wide variety of causes, no single scheme has yet been developed that addresses or describes all types of landslides. Even the terms assigned to types of landslides are undergoing standardization among geological and scientific international agencies. The major causes of landslides can be classified into two groups, namely external and internal as illustrated below: All the major causes of landslides point towards some or other form of human activity and hence it is essential to be discreet about developmental activities in areas prone to landslides. 3.3.6. Desertification: Desertification is a form of land degradation occurring particularly, but not exclusively, in semi-arid areas. While there is a clear distinction between ‘soil’ and ‘land’ (the term land refers to an ecosystem comprising land, landscape, terrain, vegetation, water, climate), there is no clear distinction between the terms ‘land degradation’ and ‘desertification’. Desertification refers to land degradation in arid, semi-arid, and sub- humid areas due to anthropogenic activities. Causes of Desertification: Natural causes of desertification: ✓ Decreased rainfall ✓ Increased temperature ✓ Lowering of water table ✓ Soil erosion ✓ Soil compaction Human-aided desertification: ✓ Overgrazing ✓ Destruction of forest belts (Deforestation) ✓ Salinization ✓ Exhaustion of the soil by intensive cultivation without restoration of fertility 3.4. Forest Resources: ❖ He we will learn and understand about the significance of forest resources and the major threats to it such as mining and dams. Due to rapid urbanization, the area of forest is decreasing all over the world. The protection of forest resources is essential for the survival of our species. Below observe the various living and non-living components of a natural forest. A. Types of Forest Resources: Forests are broadly classified into three categories from the point of view of use as a resource: (i) Old-Growth or Ancient Forests: These are uncut forests that have not been seriously disturbed by natural disasters or human activities. As a result, they have attained great age, and thereby exhibit unique ecological features. Components of Forest (ii) Second-Growth Forests: They result from secondary ecological succession that takes place when forests are cleared and then left undisturbed for long periods of time. (iii) Plantations: These are (large, artificially established) forests of commercially valuable trees. These are created mostly by clearing old-growth or second-growth forests. Differentiation characteristics of forests “Automated analysis of forest satellite imagery is not reliable for estimating forest cover.” Explanation: The Forest Survey of India (FSI) reported in 2009 that Indian forests had grown by almost 5% per year from the 1990s. They used automated analysis of forest satellite imagery. But, the above method cannot differentiate between native forests and exotic tree plantations (such as rubber, teak, pine, eucalyptus trees). The plantation forest covers have very limited value for biodiversity. Monoculture plantations are expanding by nearly 6,000 to 18,000 square kilometres per year in India. If one subtracts plantations from total forest cover then India’s native forests have actually declined at an alarming pace, from 0.8% to 3.5% per year from 2000–2005. B. Functions of a Forest: ❖ Forests help in production of timber, regulation of stream flow, control of erosion, recreation, provision of wildlife habitat, etc. Beneficial functions of forests are the following: (i) Influence on Climate The crowns of the trees hold the moisture in because the force of the wind is broken. It makes the forest cool in the summer and warm in the winter. (ii) Control of Run-off Leaves and branches of trees break the impact of rain, causing it to drip rather than have a strong force. Rain is absorbed by the ground, reducing surface run- off. (iii) Flood Control Forested watersheds help in avoiding extremes of water flow and so help in flood prevention. (iv) Wildlife Habitat Provision Wildlife uses the products of trees and forests as food and shelter respectively. (v) Prevention of Soil Erosion Water moves slowly through forested soils and stays free of sediments. (vi) Reduction of Wind Erosion Trees are used as windbreaks and slow down the force of wind. (vii) Removal of Pollutants The roots of trees absorb soil and water pollutants. Sulphur dioxide is used for metabolism of trees. Thus, forests aid in the cleansing of air, water and soil. (viii) Noise Abatement Trees act as a sound barrier. (ix) Recycling of Nutrients Forests help in nutrient recycling. (x) Provisions for Healthy Survival of Local Communities and Mankind Forests provide employment and income, aesthetic pleasure and spiritual solace. They also provide food, fiber, honey, medicinal plants and minerals. Environmental and commercial value of forests Some Uses and Benefits of Forests for Humans 3.4.1. Deforestation: Deforestation refers to the loss of forest cover; land that is permanently converted from forest to agricultural land, golf courses, cattle pasture, homes, lakes, or desert. The depletion of forest tree crown cover less than 90% is considered forest degradation. Logging most often falls under the category of forest degradation and thus is not included in deforestation statistics. Therefore, forest degradation rates are considerably higher than deforestation rates. If the current rate of deforestation continues, the world’s forests will vanish within the next 100 years—causing unknown effects on global climate and eliminating the majority of plant and animal species on the planet. A. Causes of Deforestation: The causes of deforestation are very complex. A competitive global economy drives the need for money in economically weak developing countries. At the national level, governments sell timber to raise money for projects, to pay international debt, or to develop industry. ✓ Population explosion ✓ Agriculture: shifting cultivation, overgrazing, cash-crop economy, etc. ✓ Commercial logging: cutting trees for sale as timber or pulp ✓ Poverty ✓ Mining ✓ Dams ✓ Infrastructure creation for logging ✓ Forest fires ✓ Acid rain ✓ Development projects and housing projects. Major Causes of Deforestation B. Ill effects of Deforestation: Since many people are dependent on the world’s forests, deforestation will have many social, economic and ecological effects. ✓ The major effects of deforestation on the environment are: Ill Effects of deforestation C. Environmental Impacts of Deforestation: (i) Atmosphere Less CO2 taken in, burned trees add even more CO2, which traps heat, causes more evaporation, and this leads to more precipitation. More sunlight reaches surface, less photosynthesis, increased risk of fire. This is responsible for global warming, which in turn causes deforestation (a). (ii) Hydrosphere Run-off increases, turbidity increases. More sediment at mouth of rivers, more flash floods. Increase of water temperature near river banks results in less availability of oxygen in water ways. This is responsible for degradation of aquatic habitat (b) & (d). (iii) Geosphere/Lithosphere Increased erosion from water and wind, top soil carried away, loss of minerals (C, N, etc.), soil depleted quicker, less wood for construction, fuel and other products (b). (iv) Biosphere Loss of vegetation, change of food supply, decreased habitat, decrease in number of species, decrease of diversity, decrease of pollinators and seed dispersers, loss of human cultural diversity (c) & (d). D. Solutions to the Problems of Deforestation Deforestation is a serious problem, but humans can make a difference. An individual as well as a society can practice green consumerism. The following actions could serve as effective solutions to the problem of deforestation. Reduce the consumption of forest and related products. Avoid harmful products by consumer boycotts, such as tropical rainforest wood, old-growth wood from the tropical rainforest. Boycott products of companies involved in deforestation. Compel government and industry to make changes in the forest policies. Individuals may communicate their uncertainty about the future of the world’s forests to politicians, corporate executives and non-governmental organizations through personal communication or in groups using petitions and rallies. Environmental conservation may be given importance in school curricula. E. The Measures Taken for Conserving Forest Wealth Sustainable Forest Management (SFM): SFM is the use of the world’s forests in such a way that they continue to provide resources in the present, without depriving future generations of their use. Forest Certification: Be responsible consumers. Buy wood only from companies that follow sustainable practices. Involve Local Communities in Joint Forest Management (JFM): As local communities want to continue to get the benefits they previously enjoyed, they provide labour and help in conserving biodiversity. The Government should provide them extractive reserves. These are protected forests in which local communities are allowed to harvest fruits, nuts, medicines, fibres, rubber, etc., in ways that do not harm the forest.  Improve Governance and Accountability: The Government must take bold political decisions and develop new civil society institutions to improve governance and accountability regarding forest use. Stop harmful subsidies to timber companies. Accelerate Education, Research and Training: This is to ensure that SFM and JFM can quickly become a reality. ❖ In 1988, the Government of India introduced a new forest policy that called for significant change in the management of forest land. ❖ The draft National Forest Policy 2016 continues with the national goal of maintaining a minimum of one-third of the geographical area under forest or tree cover. Types of Timber Extraction Case Studies: (i) Chipko Movement ‘ Chipko’ in Hindi means hugging or embracing. Contractors used to make huge profi ts, from the feeling of trees in the hills. The Chipko movement was the hill communities’ response to the unfair and destructive nature of this contract system. The Chipko movement spread through India during the 1970’s. As per the folk-poet Ghansyam Returi, Chipko movement is “Embrace the trees in the forests and save them from being felled! Save the treasure of the mountains from being looted away from us!” The slogan of the Chipko movement was “What do the forests bear? Soil, water, and pure air!” The Chipko movement ensured that the contract system was abolished and the indiscriminate felling of trees stopped. The Forest Development Corporation (FDC) department was formed which works for the welfare of hilly areas and the people living there. It enlightened the people about the necessity of ecological balance in the nature.  The Chipko movement took place under the leadership of Sunder Lal Bahuguna (an environmentalist and journalist) and Chandi Prasad Bhatt in Tehri Garhwal (Uttarakhand). Sunderlal along with his wife, Vimla, has given his time and talent freely to work for the good of India. He has been the catalyst of change, encouraging thousands of people to work without pay for the good of India’s people and ecology, through non-violent resistance. As a Gandhian peace worker, they do not resort to violence to achieve the change. Chandi Prasad Bhatt encouraged the development of local industries based on the conservation and sustainable use of forest weather for local benefit. Forests in Uttarakhand district covered more than 81% of its geographical area in 1950. The Government initiated the process of development by allowing a pulp and paper mill, a plywood factory and a chain of hydroelectric dams on rivers. Over-exploitation of forest resources by these industries and submergence of huge forests and agricultural areas by dams resulted in shrinking of the forests to nearly 25% of the district’s area by 1980. The poor, local population was forced to displace. The conversion of the natural mixed forests into eucalyptus and teak plantations dried up the water resources, directly affecting forest dwellers, and resulted in poverty instead of intended development.  The Chipko protests in Uttar Pradesh achieved a major victory in 1980 with a 15- year ban on green felling in the Himalayan forests of UP by the order of the then Prime Minister of India (Mrs Indira Gandhi). Since then, the movement has spread to many states in India. The movement has also helped in stopping deforestation in the Western Ghats and the Vindhyas. (ii) The Bishnois Jambhoji, a resident of a village near Jodhpur, Rajasthan had a vision in the fifteenth century that the people’s interference with nature like felling of trees, killing of animals would result in drought. Thereafter, he become a sanyasi and initiated the Bishnoi sect. He came to be known as Swami Jambeshwar Maharaj. He laid down tenets (including a ban on killing animals, a ban to the felling of khejri and other trees) for his followers. Once the Maharaja of Jodhpur sent his men to the area around the village of Jalnadi to fell the trees as he required wood for building a new palace. When Amrita Devi (a Bishnoi rural woman) saw this, she rushed out to prevent the men and hugged the first tree, but the axe fell on her. Before dying, she uttered the now famous couplet of the Bishnois, ‘A chopped head is cheaper than a felled tree’. To prevent the Maharaja’s men from felling the trees, people from 83 surrounding villages rushed to the spot and by the end of the day more than 350 had lost their lives. When the Maharaja heard about this, he was filled with regret and came to the village to personally apologize to the people. He promised them that they would never again be asked to provide timber to the ruler, no khejri tree would ever be cut, and hunting of animals would be banned near the Bishnoi villages. The village of Jalnadi thus came to be called khejari. The Bishnois have proved that human lives are a small price to pay to protect the wildlife and the forests around them. 3.4.2. Mining: Mining is the extraction (removal) of metals and minerals from the earth. A. Sustainable Mining Extraction and beneficiation of raw materials has to be Environmentally compliant (agreement or as per rules) Socially acceptable ‘‘Sustainable” Economic A mining operation is socially acceptable if It obeys standards in occupational safety and health It is accepted by the society It obeys national and international guidelines and laws It provides resettlement help It considers cultural and social constraints It provides suitable working conditions for the workers  A mining operation is economic if It fulfills the needs of the society with material and immaterial goods It is working for the long-term maximization of revenues and profit A mining operation is environmentally compliant if It does not impose any harm to the environment. B. Mining Process and the Environment Some of the major environmental impacts of mining are a result of associated mining operations as summarized below. Mining process and the environment C. Environmental Impacts of Mining Some of the major environmental impacts of mining are the following: Ecological Impacts Degradation of Land: Due to leaching out of toxic elements, the growth of vegetation is adversely affected. Loss of fauna and flora is also observed. Socio-economic Impacts Pollution of Water Resources: Even when drainage is controlled, some leaching and release of harmful elements (e.g. Pb, Cd, etc.) into the surface and groundwater occurs. It affects the ecosystem stability adversely due to alterations in water quality and availability. Pollution of Air: Mining processes emit dust and gases which cause air pollution. These air pollutants have adverse impacts on historical monuments and religious places. Problems in Rehabilitation of Affected Population: It is one of the biggest problems due to economic constraints.  To sum up, Mines Always cause Environmental impacts…… But... it is usually cheaper to prevent the impacts than to deal with them after they have already happened. It is easier to prevent the impacts if one knows about them in advance. Impacts of mining activities D. Impact of Mining Activities on Labourers Studies on mining activities in the Aravalli's have shown that Labourers are not provided with any health care Tuberculosis, silicosis and other lung diseases are very common Diseases make labourers invalid and even kill them by the age of 40 The condition of women workers (30–40%) and child labourers (10–15%) is the worst. E. Impact of Mining on the Culture and Lifestyle of People From the gold and copper project, 1000 m3 of conc. cyanide were released into a river in 1984 on the OK Tedi Island in new Guinea. It caused extensive environmental damage, devastated the ecosystem and destroyed the culture and lifestyle of the native Wopkaimin people. Case Studies: (i) Impact of Coal Mining on Vegetation Meghalaya, one of the seven states of North-East India, is honoured with rich natural vegetation as well as large reserves of mineral resources. In the early 1970s, coal mining was initiated in the Jaintia Hills district of Meghalaya. Since then, mining and the area affected by it is increasing day by day. The dense forest areas were converted into open forests and the considerable area of the forests was converted into a nonforest. Extensive coal mining has led to landscape damage and damage to the biological communities in enormous ways. The number of trees and shrub species drastically decreased due to mining. The unfavourable habitat conditions prevailing in the coal-mining areas has reduced the chances of regeneration of species, thereby, reducing the number of plant species in the mined areas. (ii) Marble Mining and Drying of Lakes in Rajasthan The Aravalli Hills are the lifeline of Haryana, Rajasthan, and Gujarat. They control the climate and drainage systems of the region. The hills also act as a watershed for the region. The hills are also known for their rich deposits of teak, marble and granite. About 1,75,000 workers are employed in mining and related industries. About 9700 industrial units are connected with mining in Rajasthan alone. Over the past 20 years, the forest cover has been depleted by 90% in Rajasthan due to large-scale mining. When the mines reach below the underground water l evel, a cone of depression is formed that sucks water from the surrounding areas, drying up wells and lakes and affecting agriculture. The Rajasamand Lake in Rajasthan had not dried up for at least 300 years. However, in 2001, this finally did happen because of a decade of marble mining in the Rajnagar area. While mining has led to the depletion of water, mining waste has destroyed fertile land. (iii) Jhansi Open-Cast Mining Site: Uttar Pradesh, India The Bundelkhand region occupying about 71818 km2 in Uttar Pradesh is known for its rich deposits of graphite, saltpetre, sand, etc. Presently there are more than 300 active mining sites in the Jhansi district alone. Mining and its allied activities significantly contributed towards infrastructure development and raising the living standards of the people. Deforestation, dust generation, noise, air and water pollution as well as resource depletion are common hazards associated with open-cast mining widely prevalent in the Jhansi region. 3.4.3. Dams and their Effects on Forest and Tribal People: A dam is a huge and giant barrier constructed across a river to obstruct its natural flow. Consequently, an enormously large artificial lake is created to store water. The water thus stored is utilized for multipurpose services such as power generation, irrigation, flood and drought control, etc. Construction of dams in countries like India and China displace a large number of people because of the high population densities of these countries. In India, dams account for 75–80% of displacement of about 4–5 crore people. Out of the total people displaced, only 25% have been rehabilitated so far. Tribal people are economically, socially and politically the weakest and the most deprived community in India. A. Problems associated with effects of dams on tribal people are: No Human Rights Human rights violations create unrest among tribals. No Basic Amenities They are forced to migrate to urban slums in search of employment. They become landless labourers in rural areas. A majority of tribal people end up with less income than before, less resources of the common people, inferior houses, etc. They are forced to live without drinking water, sanitation, health care, and other basic amenities. No Benefit Sharing They hardly get to share the benefits of development projects that cause their displacement.  No Home Tribal people have been forced to leave their ancestral homes and go elsewhere. No Cultural Identity Tribal communities get dispersed, traditional support systemsget broken and cultural identity gets devaluated because of dams. Problems associated with effects of dams on tribal people: Loss of B. Major effects of Dams on Forests are: All major dams are constructed in mountainous regions, where there is plenty of rainfall. These places are covered with rich vegetation and forests. The forests area which is supposed to get submerged is cleared off by the contractors. The forest is also cleared for approach roads, offices, residences and for storage of construction material. As more and more workers occupy the dam sites, forests are destroyed for getting fuel and timber. Irrecoverable Loss to Ecosystems and Biodiversity Forest fragmentation causes serious irrecoverable loss of species and ecosystems. This is because some species of animals and plants require large continuous areas of similar habitat to survive. 3.5. Water Resources: Water resources are sources of water that are useful or potentially useful to humans. Water is a prerequisite for the existence of life. Plants, animals, and human beings cannot survive without water. Water is used in agricultural, household, industrial, recreational and environmental activities. Water is essential for economic growth, environmental stability, biodiversity conservation, food security and health care. A. The Water Cycle: Water cycle is the continuous movement of water above and below the surface of the earth. It is driven by the sun. The sun heats water in seas and oceans. Water evaporates into the air as water vapour. Snow and ice can sublime directly into water vapour. Rising air currents take the water vapours into the atmosphere where cooler temperatures help them to condense into clouds.  Air currents move clouds; they collide, grow, and fall out of the sky as precipitation. Some precipitation falls as snow, and can accumulate as ice caps and glaciers. Most water falls back into the oceans or onto land as rain where the water flows over the ground as surface run-off. Much of the run-off is soaked into the ground as infiltration. Some run-off is stored as fresh water in lakes. Some run-off enters rivers in valleys in the landscape. Some water infiltrates deep into the ground and replenishes aquifers. This helps in the long-term storage of freshwater. Some groundwater finds openings in the surface of land and freshwater springs come out. Some rainwater flows through rivers back into the ocean, where the water cycle begins again. B. Sources of Water: 97.5% of water on the earth is salt water in oceans. Only 2.5% is fresh water. Sources of fresh water are briefly described below: Surface Water: Water in a lake, river or freshwater wetland is known as surface water. Groundwater: Fresh water located in the pore space of soil and rocks is called groundwater. Ice Caps and Glaciers: Fresh water from ice caps and glaciers is relatively inaccessible. Distribution of the earth’s water C. Availability of Water: World’s water content  Water availability versus population Availability of Water in India India is the wettest country in the world, but rainfall is highly uneven with space and time. Rainfall is high in the North-East but extremely low in Rajasthan. Out of 4000 billion cm3 rainfall received, about 600 billion cm3 is put to use so far. With 16% of the world’s population, India has only 4% of global water resources. The city of the Delhi gets 60 hours of rain a year, and only 11 hours of it are contained while the rest is wasted. Every monsoon we see flooded underpasses and buses floating by. D. Causes of Water Crisis in the World Growing population and with better lifestyles, per capita use of fresh water is increasing, causing shortage of water. Spatial and temporal variations in available water is also responsible for water crisis. Freshwater resources are reduced by pollution. Industrial wastes, chemicals, human waste and agricultural wastes (fertilizers, pesticides and pesticide residues) are disposed off within water. Increase in extreme weather conditions like floods, droughts, typhoons, cyclones, etc., are also responsible for worsening of water quality and availability. Recently, it is estimated that ✓ Climate change will account for about 20% of the increase in global water scarcity ✓ 50% of the population of developing countries are exposed to polluted water sources (E) Importance of Water: Next to air, water is the most essential thing for our survival. We must drink water to avoid dehydration which means less or insufficient levels of water and important body salts of sodium and potassium in our body. The kidneys, brain, heart and other important body organs cannot function properly without salt and water. Water is also helpful in maintaining the relatively constant body temperature through the homeostasis process. It helps in avoiding upsetting of metabolic reactions by preventing sudden changes in temperature. Water helps in the digestion process. Different types of food products, after being broken down to simple molecules (e.g. large starch molecules are broken down to simple sugars) are solubilized in the universal solvent ‘water’. Different enzymes facilitate this digestion process.  Oxygen gas is also dissolved in water to some extent. This Dissolved Oxygen (DO) helps in the respiration process of many organisms who live in water and spend most of their time underwater. “Life is impossible without water. It is needed for health, ecosystem services, economic development, poverty reduction, protection of greenery, production of food and imparting of aesthetic beauty.” (F) Impacts of Over-utilisation of Underground and Surface Water The over-utilisation of underground and surface water has the potential to alter, sometimes irreversibly, the integrity of freshwater ecosystems. Some of the major impacts are summarised below: Loss of Integrity of Freshwater Ecosystems: Human activities for infrastructure development like creation of dams, land conversion, etc., are responsible for this loss of integrity of freshwater ecosystems. Water quality and quantity, fisheries, habitats, etc., are at risk due to this loss of integrity.  Risk to Ecosystem Functions: Population and consumption growth increases water abstraction and acquisition of cultivated land. Virtually all ecosystem functions including habitat, production and regulation functions are at risk. Depletion of Living Resources and Biodiversity: Overharvesting and exploitation causes groundwater depletion, collapse of fisheries. Production of food, quality and quantity of water and supply of water gets badly affected by these depletions of living resources and biodiversity. Pollution of Water Bodies: Release of pollutants to land, air or water alters chemistry and ecology of water bodies. Greenhouse gas emissions produce significant changes in run-off and rainfall patterns. Because of water pollution, water supply, habitat, water quality, food production, climate change, etc., are at risk. 3.5.1. Uses and Overuses of Water Resources (A) Uses of Good-Quality Water Good-quality water is needed for all direct or indirect uses of water as illustrated below: Direct and indirect uses of water resources by humans and ecosystems  According to the Union Ministry of Water Resources (MoWR), 80 per cent of India’s utilizable water is devoted to agriculture, mostly for irrigation. Demand from the domestic sector is about 5% of the annual freshwater withdrawals in India. The industrial sector in India is the second largest user of water. As a result of growing sectoral demands and declining water supplies, competition is growing rapidly. From public systems, allocation of water is not based on fundamental rights consideration or social, economic or environmental considerations, Thus, water allocation is inequitable. Growing inequity in access to and control over water leads to conflicts among different sectors. The poor need water for both domestic as well as productive purposes which include growing food, fruit, vegetables, rear livestock, etc.  The rich residents of cities consume around 200 litres per capita per day. It is believed that finding ways of providing similar quantity of water in support of the livelihoods of the rural poor is vital. India’s supply of water is rapidly decreasing mainly due to mismanagement of water resources, although over-extraction and pollution are also significant contributors. (B) Sectoral Demand of Water: As per the ministry of Water Resources (MoWR) assessment, 2000; water requirements for various sectors in India is: Over-exploitations of water resources and the problem of availability of safe drinking water: Excessive Withdrawal from Surface Waters Size of the sea is shrinking (e.g. the Aral sea in the former Soviet Union) primarily by the diversion of the inflowing rivers to irrigate water-intensive cotton and rice crops. In 2007, about 60% of the Aral Sea’s volume had been lost, its depth had declined by 14 metres. Moreover, its salt concentration had doubled. Inefficient Use of Freshwater Excessive consumption by individuals, leakage in water delivery systems, inefficient use by industry and poor irrigation practices can all contribute to situations where there is not enough water for all uses. Excessive Withdrawal of Water from Underground Aquifers Excessive freshwater abstraction along much of the west coast of India has allowed sea water to enter aquifers. It resulted in making the water saline and unfit for human use. The above problem has worsened due to leaching of excess irrigation water containing pesticides, fertilizers, etc., into these aquifers. (C) Water Conservation “ Water conservation is the most cost-effective and eco-friendly way to reduce our demand for water.” Need for Water Conservation: On an average, a citizen in most parts of the world is allocated 2.5 gallons of water per day for sustainability. However, the average American citizen uses 80–100 gallons of water per day. The poor do not have access to safe drinking water. More than 4000 children are dying every day as a result of diarrhoeal diseases caused from unsafe drinking water, lack of access to sanitation and inadequate availability of water. Thus, it is very essential to conserve water. Measures to Conserve Water: Recharge groundwater by harvesting rainwater. Use water wisely for household, agricultural and domestic purposes. Reuse water whenever possible. For example, waste water after bath can be used for the toilet. Avoid transmission and distribution losses by checking leaks in pipes, hoses, etc. Prevent flow of untreated sewage to lakes and rivers. This will reduce the likelihood of water pollution and help in water conservation. Collect water by building dams and reservoirs, and digging wells. Use drip irrigation, precision sprinklers for agriculture. Practice organic farming. Adopt fairer policies for treatment, access and pricing of water. Prevent flow of industrial effluents to natural water resources to avoid water pollution. Do protect forests to protect rivers, lakes, wells and other sources of water. (D) Quality Aspects Impacts of Poor Water Quality Poor water qualities are responsible for public health hazards, damage to ecosystems, and adverse economic consequences. A good status of water biology and healthy aquatic organisms are necessary for obtaining a good status of water quality. Characteristics of a Good-Quality Water It is transparent, colorless and odourless. It has sufficient oxygen concentration for marine life to survive. It is free from bacteriological contamination. It is free from any water pollution. It is free from excessive nutrients like N, P, etc., which are responsible for eutrophication. It is fit for the intended use. (E) Self-Purification of Rivers A variety of plant and animal species live in seas and rivers. If pollution does not attain a critical level, water can purify itself, i.e. progressively eliminate polluting agents. The phenomena of filtration and oxidation, combined with the action of organisms (insects, bacteria, plants, etc.) living in the water and on the banks helps water maintain its quality and preserve its ecosystem’s balance. Various river-self purification mechanisms are: (i) Phyto-remediation Aquatic plants and vegetation on the river banks absorb (nitrate, phosphate and other nutrients) and remove pesticides and heavy metals from water. In this way quality of water in the river is largely improved. (ii) Aeration When a river runs through hills, turbulence mixes air into water increasing the dissolved oxygen (DO). The increased DO concentration facilitates many chemical and microbiological processes in water to reduce the pollutant concentration. (iii) Sedimentation In this mechanism, sand in the riverbed acts as a sink for the pollutants. From the hills, when river reaches flat lands, it spreads, its velocity reduces and suspended pollutants settle on the sand bed. (iv) Adsorption Pollutants are adsorbed onto sand particles, plant surfaces, rocks, etc., and thereby their concentrations get reduced in the river water. (v) Dilution When a polluted river is joined by less polluted tributaries or during the rainy seasons, the volume of water in the river is increased. It reduces the concentrations of pollutants by dilution process. vi. Floatation After rapid mixing of water in falls, air bubbles act as vehicles to lift many pollutants to the water surface in the form of froth (or a layer of foam). This froth is exposed to the atmosphere, and it facilitates oxidation of pollutants to less harmful forms. The top layer is also directly exposed to sunlight; so either by increased temperature or due to various photochemical reactions, volatile organic compounds are removed from the top layer. At different sections of the river, various artificial traps help in the removal of this froth and thus rivers get self-purified. vii. Microbial Degradation The shallow and turbulent water results in high aeration of water. It helps in growth of bacteria and other microorganisms. They help in river purification by microbial degradation of pollutants. (F) Major Water-Quality Issues: Wastes introduced by humans into rivers, lakes, groundwater aquifers and the oceans modify the environmental water quality and make huge quantities of water unsuitable for various uses. (G) Major Factors Responsible for Water-Quality Degradation: (i) Insufficient and incomplete treatment of domestic and industrial wastewater (ii) Eutrophication (iii) Pathogens, and pesticide contamination (iv) Stagnation of domestic sewage and contamination of groundwater Important quality issues of water (H) Water-Borne Diseases Water-borne diseases are illnesses caused by consuming water contaminated by pathogenic microorganisms. Illnesses caused by consuming contaminated water  Often lack of access to hygienic water, poor sanitation and rise in population of pathogenic microorganisms like protozoa, viruses, bacteria and intestinal parasites breeding in on water are considered the main causes of water-borne diseases. According to the World Health Organization, diarrhoeal disease is responsible for the deaths of 1.8 million people every year and a majority of them are children in developing countries. A few water-borne diseases are summarized as:  The best ways to prevent water-borne diseases are: (i) avoid drinking untreated water, (ii) avoid consuming undercooked food, (iii) maintain good personal hygiene (e.g. wash hands before eating), and (iv) educate for clean sanitation. (I) Fluoride Problem in Drinking Water At low concentrations in drinking water, fluoride has beneficial effects on teeth. But excessive exposure to fluoride in drinking water can give rise to number of adverse effects. Although the concentration (mg/litre) of fluoride added to water can be controlled, but we cannot control the dose (mg/day). This is because one cannot control how much water people drink or how much fluoride they get from other sources. (i) Sources of Fluoride (a) Fluoridated water supplies (b) Food processed with fluoridated water (c) Mouthwash enhanced with fluoride (d) Toothpaste enhanced with fluoride (e) Food supplements (ii) Fluoridation is not Necessary (a) The level of fluoride in mother’s milk is 0.004 ppm. It means a bottle-fed baby, where fluoridated tap water (with 1 ppm fluoride) is used to make up the formula milk, will get 250 times more fluoride than nature intended. (b) Fluoride works from the outside of the tooth, not from inside the body, so it is not required to swallow fluoride or drink fluoridated water. (iii) Fluoride’s Dangers Fluoride damages teeth, bone, brain and endocrine system. It may cause osteosarcoma. (a) Fluoride damages the teeth: A permanent discoloration and mottling of the tooth enamel (dental fluorosis) is caused by a child’s ingestion of fluoride (0.5–1.5 ppm) before its permanent teeth have erupted. (b) Fluoride damages the bone: In an area of high natural levels of fluoride (1.5–5.5 ppm), fluoride can weaken bone and increase the risk of fractures. c) Fluoride damages the brain: Fluoride lowers the IQ of children, even when present at 1.8 ppm in water. It is apparent that fluorides have the ability to interfere with the functions of the brain. Dangers of fluoride consumption: (iv) Defluoridation of Water Defluoridation of water can be carried out by (a) Reverse osmosis filtration (b) Activated alumina defluoridation filter (c) Nalgonda technique (J) Pesticide Removal Methods from Drinking Water  Water contaminated or suspected of being contaminated by pesticide and synthetic/volatile organic compounds can be purified using following methods 3.5.2. Floods Waterways are formed slowly over time, and their size is proportionate to the amount of water that normally accumulates in that area. Sometimes, due to excessive runoff from precipitation or snowmelt or by coastal storm surges or other tidal phenomenon, there is suddenly a much greater volume of water. As a result, the normal waterways overflow, and the water spreads out over the surrounding land. This anomalous accumulation of water in an area of land is called flood. Flood can be defined as a temporary rise of the water level, as in a river or lake or along a seacoast, resulting in its spilling over and out of its artificial or natural confines onto land that is normally dry or flood is a temporary covering by water of land not normally covered by water. (A) Effects of Flood The effects of flood are briefly described below: (i) Primary Effects Flood can cause either physical damage or casualties. (a) Physical Damage: Flood can damage any type of structure resulting in physical damage to canals, bridges, sewerage systems, roadways, cars, buildings, etc. (b) Casualties: Humans and animals die due to drowning. Floods can also cause casualties through epidemics and water-borne diseases. The spawning grounds for fish and other wildlife can become polluted or completely destroyed. (ii) Secondary Effects Secondary effects of floods are briefly summarized below: (a) Contamination of Water: Clear drinking water becomes scarce because of contamination of water due to floods. (b) Spread of Water-borne Diseases: Floods are responsible for unhygienic conditions leading to various diseases. c) Loss of Harvest: The entire harvest can be lost due to floods leading to shortage of food crops and this badly affects the food supplies. d) Death of Some Nontolerant Tree Species: Floods can lead to suffocation and death of some nontolerant tree species. (iii) Tertiary Effects / Long-term Effects Floods are responsible for food shortage, leading to price increases. They are also responsible for temporary decline in tourism. Money is also, needed for rebuilding any type of structure damaged by flood. All the above effects (where economic hardship in concerned) is discussed in tertiary effects or long-term effects. (B) Benefits of Floods The more frequent and smaller floods can bring following benefits: (i) Water Availability: Floods helps in recharging of groundwater. Flood waters provide much-needed water resources in arid and semi-arid regions where precipitation events are unevenly distributed throughout the year. (ii) Ecosystem Services: Specially freshwater floods play an important role in maintaining ecosystems in river corridors and in maintaining floodplain biodiversity. (iii) Increase in Soil fertility: Floods help in making the soil more fertile by providing nutrients to soil. (iv) Improved Fisheries: Flooding adds a lot of nutrients to lakes and rivers which help in improved fisheries for some years. Fish, like weather fish, make use of floods to reach new habitats.  (v) Benefits to Birds: Birds profit from the boost in production caused by flooding. (vi) Higher Viability of Hydro-energy Projects: The viability for hydrological based renewable source of energy is higher in flood-prone regions. (C) Flood Disaster Impact Minimisation (i) If it has been raining hard for several hours, or steadily raining for several days, individuals must listen carefully to the radio or TV flood forecasts issued by the Central Water Commission. (ii) They should listen to and follow the instructions of the emergency services. (iii) They should extend all possible help to the administrative and engineering agencies of the states/union territories to take appropriate measures. 3.5.3. Drought Drought may be defined as the deficiency of rainfall (relative to the statistical multi- year average for a region ) over an extended period of months or years. (A) Types of Drought (i) Meteorological Drought It is brought about when there is a prolonged period with less than average rainfall. As per the India Meteorological Department (IMD), meteorological drought occurs when the seasonal rainfall received over an area is less than 75% of its long-term average.  The drought can be classified as ‘moderate’ or ‘severe’ depending on the rainfall deficit between 26% to 50% or exceeds 50% respectively. Usually, meteorological drought precedes the other kinds of drought. (ii) Agricultural Drought It is a drought that affects crop production or the ecology of the range. It is caused by extended period of below-average rainfall resulting in a shortfall in water for the crops. It is typically witnessed after a meteorological drought but before a hydrological draught. (iii) Hydrological Drought It is brought about when the water reserves available in sources such as reservoirs, lakes or aquifers fall below the statistical average. It tends to show up more slowly because it involves stored water that is used but not replenished. (B) Consequences of Drought The impacts of drought are (i) Impact on Agriculture: Droughts are responsible for diminished crop growth or diminished production yields due to lack of water for irrigation. Famine may also be caused. (ii) Impact on Environment: When drought hits an area suffering from desertification and erosion, dust storms and/or dust bowls result which further erode the landscape. Drought also affects both terrestrial and aquatic wildlife through habitat damage. (iii) Impact on Health: Drought is responsible for malnutrition, dehydration and related diseases. Drought can also reduce water quality, because lower water flows reduce dilution of pollutants and increase contamination of remaining water sources. (iv) Social Impacts: Subsistence farmers are forced to migrate during drought because they do not have alternative food sources.  Mass migration results in internal displacement and international refugees. Droughts are also responsible for snake migration and increases in snakebites. In totality, a situation of social unrest arises because of drought. A war can also happen over natural resources including water and food. (v) Economic Impacts Droughts lead to reduced electricity production due to reduced water flow through hydroelectric dams and insufficient available coolant for power stations. Droughts also lead to shortages of water for industrial users Effects of drought (C) Strategies for Mitigation of Drought Impacts Society’s vulnerability to drought is minimized through the following actions: (i) An artificial technique of cloud seeding helps in inducing rainfall. (ii) For consumption or irrigation, desalination of sea water can be done in times of scarcity. (iii) Carefully planned crop rotation can help to minimize soil erosion. This also allow farmers to plant less water-dependent crops in drier years. (iv) Collection and storage of rainwater through rainwater harvesting is very useful. (v) Regulating the use of water-intensive home maintenance tasks and the use of sprinklers, hoses, etc., on outdoor plants. (vi) Redirecting rivers for irrigation in drought-prone areas. (vii)Treatment and purification of sewage wastewater for reuse. (viii) Continuous observation of rainfall levels and comparisons with current usage levels can help prevent man-made drought. 3.5.4. Conflicts Over Water Water might be the source of the world’s next big conflict. This is because fresh water availability is limited but its demand is rising day by day. Demand for water (i) Infrastructure Failure The cost and environmental risks due to failure of drinking and wastewater infrastructure are very high, costing billions of rupees. (ii) Rapid Urbanization It requires significant investment in water infrastructure in order to deliver water to individuals and to process the wastewater so as to avoid unacceptable public health risks. (iii) Population Growth The demand of water for residential and industrial purposes increases with increase in population. (iv) Increasing Affluence Increasing affluence especially in India and in China, inevitably means more water consumption. Expansion of business activity requires more water supply. (v) Climate Change Climate change poses a series of risks to water availability as a result of the following: (a) Rising temperatures could increase the rate of evaporation from surface waters and reservoirs and lead to loss of freshwater held in glaciers. (b) Increased rainfall might come in the form of storms that lead to floods. (c) Climate change could increase annual precipitation and make more freshwater available in some places leading to difficulty in water management systems.  Where water crosses cultural, economic, political or legal boundaries, the stage is set for disputes between different users. The users try to safeguard access to a vital resource, while protecting the natural environment. Management and transformation of water conflicts require implementation of right strategies for anticipation, addressing and mediation between competing users. If the strategies are not implemented, the conflicts over water are likely to become more frequent, more intense and more disruptive around the world. Water conflicts in India: Water conflicts in India can be classified as per the following themes: Conflicts over (a) equity, access and allocations, (b) water quality, (c) dams and displacement, (d) privatization, (e) contending water uses, (f) sand excavation and mining, (g) trans-boundary conflicts, and (h) micro-level conflicts are also present. Some specific examples of conflicts over water: (i) Conflict between Poor and Rich The rural peasants are poor and only require a pot full of drinking water. The urban elite is rich and uses large quantities of water for meeting the requirements of water-intensive sewage systems, space cooling, gardening, etc. This results in conflict. (ii) Conflicts between Agricultural Usage of Water Conflict also exists between water-intensive cultivation of commercial crops for high cash returns and wise water use for protective irrigation of necessary food crops essential for survival. (iii) Interstate Conflicts Sometimes water projects of upstream states influence the quantity and quality of water flow in the basin. This reduces the possibilities of water use by downstream states resulting in inter-state conflicts. (iv) Intrastate Conflicts State-planned extraction of timber or minerals in the river catchment affect the river flow and generate conflicts downstream. State-planned agricultural production based on large irrigation projects to generate marketable surpluses of cash crops conflicts with people’s needs for local food production. (v) Across Borders Conflicts India, Bangladesh and Nepal are disputing the best use of water of the Ganges–Brahmaputra basin. India and Nepal want to exploit the basin’s huge hydroelectric power-generating potential, whereas Bangladesh wants the water management in such a way so as to minimize water shortages during dry months and flooding during monsoon months. 3.6. Heating of earth and circulation of air; air mass formation and precipitation: 3.6.2. Heating of Earth:  Atmosphere is more transparent to incoming short-wave radiation than to outgoing long-wave radiation The temperature of a body determines wavelengths of energy emitted. Solar radiation has high energy (shortwave) that readily penetrates the atmosphere. Earth emits low-energy (longwave) radiation that is absorbed by different gases in the atmosphere  Energy in = energy out Half of solar radiation reaches Earth (latent & sensible heat). The atmosphere is transparent to shortwave but absorbs longwave Radiation (greenhouse effect). The atmosphere is heated from the bottom by longwave radiation and convection.  The atmosphere is heated from the bottom. Therefore it is warmest near the bottom, and gets colder with increasing elevation. Except the stratosphere is heated from the top – ozone absorption of incoming UV. Mesosphere and Thermosphere have little impact on the biosphere.  Earth rotates on its axis from west to east, the Moon and the Sun (and all other celestial objects) appear to move from east to west across the sky. Because of the Earth’s magnetic field, it rotates from west to east. Earth rotation appears counterclockwise when viewed from above the North Pole, and appears clockwise when viewed from above the South pole. It is common to all the planets in our solar system except Venus and Uranus, according to NASA 3.6.2. Air Pressure (High or Low): Standing on the ground and looking up, you are looking through the atmosphere. It might not look like anything is there, especially if there are no clouds in the sky. But what you don’t see is air – lots of it. We live at the bottom of the atmosphere, and the weight of all the air above us is called air pressure. Above every square inch on the surface of the Earth is 14.7 pounds of air. That means air exerts 14.7 pounds per square inch (psi) of pressure at Earth’s surface. High in the atmosphere, air pressure decreases. With fewer air molecules above, there is less pressure from the weight of the air above. Pressure varies from day to day at the Earth’s surface - the bottom of the atmosphere. This is, in part, because the Earth is not equally heated by the Sun. Areas where the air is warmed often have lower pressure because the warm air rises. These areas are called low pressure systems. Places where the air pressure is high, are called high pressure systems.  Air near the surface flows down and away in a high pressure system (left) and air flows up and together at a low pressure system (right). A low pressure system has lower pressure at its center than the areas around it. Winds blow towards the low pressure, and the air rises in the atmosphere where they meet. As the air rises, the water vapor within it condenses, forming clouds and often precipitation. Because of Earth’s spin and the Coriolis effect, winds of a low pressure system swirl counterclockwise north of the equator and clockwise south of the equator. This is called cyclonic flow. On weather maps, a low pressure system is labeled with red L.  A high pressure system has higher pressure at its center than the areas around it. Winds blow away from high pressure. Swirling in the opposite direction from a low pressure system, the winds of a high pressure system rotate clockwise north of the equator and counterclockwise south of the equator. This is called anticyclonic flow. Air from higher in the atmosphere sinks down to fill the space left as air is blown outward. On a weather map, you may notice a blue H, denoting the location of a high pressure system. Air Pressure was measured by using Barometers, how much the Mercury liquid present in barometer was pushed by the air (pressure) and the measurement was made/denoted in Millibars (mb) Air Pressure depends on Temperature and Density of the air. If pressure increases on air, the temperature of air increases and if pressure decreases automatically the temperature of air decreases. This explains why air gets colder at higher altitudes, where pressure is lower. 3.6.3. Circulation of Air/Atmospheric Circulation: Even with disruptions like weather fronts and storms, there is a consistent pattern to how air moves around our planet’s atmosphere. This pattern, called atmospheric circulation, is caused because the Sun heats the Earth more at the equator than at the poles. It's also affected by the spin of the Earth. In the tropics, near the equator, warm air rises. When it gets about 10-15 km (6- 9 miles) above the Earth surface it starts to flow away from the equator and towards the poles. Air that rose just north of the equator flows north. Air that rose just south of the equator flows south. When the air cools, it drops back to the ground, flows back towards the Equator, and warm again. The, now, warmed air rises again, and the pattern repeats. This pattern, known as convection, happens on a global scale. It also happens on a small scale within individual storms.  Even with disruptions like weather fronts and storms, there is a consistent pattern to how air moves around our planet’s atmosphere. This pattern, called atmospheric circulation, is caused because the Sun heats the Earth more at the equator than at the poles. It's also affected by the spin of the Earth. In the tropics, near the equator, warm air rises. When it gets about 10-15 km (6- 9 miles) above the Earth surface it starts to flow away from the equator and towards the poles. Air that rose just north of the equator flows north. Air that rose just south of the equator flows south. When the air cools, it drops back to the ground, flows back towards the Equator, and warm again. The, now, warmed air rises again, and the pattern repeats. This pattern, known as convection, happens on a global scale. It also happens on a small scale within individual storms. Air in the atmosphere moves around the world in a pattern called global atmospheric circulation  But because Earth is spinning, the air that moves north and south from the equator also turns with the spin of the Earth. Air going north turns to the right. Air traveling south turns to the left. The power of Earth’s spin to turn flowing air is known as the Coriolis Effect. If the Earth didn’t spin, there would be just one large convection cell between the equator and the North Pole and one large convection cell between the equator and the South Pole. But because the Earth does spin, convection is divided into three cells north of the equator and three south of the equator – Hadley Cell, Ferrel Cell and Polar Cell. Formation of Hadley Cell (1): Insolation in tropical areas causes warm air to rise and spread polewards, carrying heat energy. Formation of Hadley Cell (2): Air cools and begins to fall at about 30ºN and 30ºS of Equator. Cooled air returns to the Equator. This circulation of air is caused by solar heating. Heat energy is transferred from the Equator to subtropical latitudes. It is called the HADLEY CELL Formation of Polar Cell (1): Intensely cold, dense air sinks at the poles, then blows as surface winds towards the Equator. Formation of Polar Cell (2): At about 60ºN and 60 ºS, the cold polar air is warmed in contact with the earth’s surface. This warmed air rises and returns polewards, carrying heat energy. This circular motion is called POLAR CELL Formation of Ferrel Cell (1): The Hadley Cell is driven by differences in heat energy at the Equator. As the air in the Hadley Cell falls at about 30ºN and 30ºS, it pulls the air beside it down as well, due to friction Formation of Ferrel Cell (2): The Polar Cell is driven by differences in heat energy. Cold polar air falls and spreads towards the Equator. As the air in the Polar Cell rises at about 60ºN and 60ºS, it pulls the air beside it up as well, due to friction. Formation of Ferrel Cell (3): Unlike the Hadley and Polar Cells, the Ferrel Cell is not driven by differences in heat energy. The Ferrel Cell is caused by friction where air is in contact with the other two cells. The Hadley Cell drags air down at about 30ºN and S The 3 Cell together: The transfer of Heat Energy from Equatorial to Polar Areas: Air carrying energy from the Equator in the Hadley Cell comes into contact with air in the Ferrel Cell, there is a transfer of heat energy into the Ferrel Cell. There is a similar transfer of heat energy from the Ferrel Cell to the Polar Cell. In this way, heat energy is transferred from the Equator, where there is a surplus of energy, to the poles where there is a deficit. The corresponding movement of colder air: In the Polar cell cold air from polar regions flows to mid-latitudes as polar easterly winds. In the Ferrel Cell there is a movement of cold air at high altitude. In the Hadley Cell, cooler air moves from the subtropics to the Equator. Pressure Belts: Rising air at the equator causes the equatorial belt of low pressure. Descending air at about 30oN and 30oS causes the sub-tropical belt of high pressure. Rising air at about 60oN and 60oS causes a mid-latitude belt of low pressure. Descending air at the poles causes the polar high pressure areas Surface wind patterns: Winds always blow from high pressure to low pressure. They are deflected because of the Coriolis Force which come about because of the rotation of the earth. Winds in Northern Hemisphere are deflected to the right. Winds in the southern hemisphere are deflected to the left. These wind belts shift seasonally. Seasonal shift of the cells or Seasonal shift of Radiation on Globe: Tilt of the Earth’s axis towards or away from the sun creates the seasons When the north pole tilts toward the sun, it gets more radiation – more warmth during the summer When the north pole tilts toward the sun, the south pole tilts away So when it’s summer in the north, it’s winter in the south.  When the north pole tilts away from the sun, it gets less radiation – So it’s colder during the winter When the north pole tilts away from the sun, the south pole tilts toward it. When it’s winter in the north, it’s summer in the south. Air Circulation patterns are modified by the distribution of oceans and continents: High heat capacity of water and ocean currents buffer ocean temperatures Land temperatures fluctuate more, especially in higher latitudes These differences in surface energy balance influence air movements, and create prevailing winds In summer at 60 ºN & S, air descends over cold ocean (high pressure) and rises over warm land (low pressure) Cool equator-ward flow of air on West coast of continents Warm poleward flow of air on East coasts of continents 3.6.4. Air Mass formation and Precipitation: Air mass is an extremely large body of air in the atmosphere whose properties – temperature, humidity and lapse rate, which is the decrease of atmospheric temperature with height, are largely uniform over an area which can be several hundred kilometers across the surface of the earth. Climate science defines air mass as a relatively huge bulk of air that is distinctive by its homogeneity of temperature and moisture content. Another definition is “An air mass is a large body of air with generally uniform temperature and humidity”. The area over which an air mass originates is what provides it’s characteristics. The longer the air mass stays over its source region, the more likely it will acquire the properties of the surface below. As such, air masses are associated with high pressure systems. Two different air masses can be separated and the line of distinction is called a front. It is along with these fronts that weather formation occurs.  Air masses are slowly pushed along by high-level winds, when an air mass moves over a new region, it shares its temperature and humidity with that region. So the temperature and humidity of a particular location depends partly on the characteristics of the air mass that sits over it. Storms arise if the air mass and the region it moves over have different characteristics. For example, when a colder air mass moves over warmer ground, the bottom layer of air is heated. That air rises, forming clouds, rain, and sometimes thunderstorms. When a warmer air mass travels over colder ground, the bottom layer of air cools and, because of its high density, is trapped near the ground. In general, cold air masses tend to flow toward the equator and warm air masses tend to flow toward the poles. This brings heat to cold areas and cools down areas that are warm. It is one of the many processes that act towards balancing out the planet’s temperatures. Formation of Air Masses: Differences in air pressure are caused by unequal heating of earths surface. Hot air rises and cool air sinks. Air Masses are most common in the tropics, subtropics, and high latitudes. The zones from which air masses grow are called “source regions.” These are generally tracts of ocean, desert or snow-covered plains. The large surfaces with uniform temperatures and humidity, where air masses originate are called source regions. Uneven warming and cooling of the earth’s surface by the Sun gives rise to air masses. Ideal source regions are areas of High Pressure. Map showing position of various Air masses Cold Front: A cold front forms when a cold air mass is actively underriding a warm air mass. As a cold front advances, the warm air ahead of it is forced upward. This displacement often creates cloudiness and relatively heavy precipitation along and immediately behind the ground level position of the front.  Because of friction with the ground, the advance of the lower portion of a cold air mass is slowed relative to the upper portion. As a result, a cold front tends to become steeper as it moves forward and usually develops a protruding “nose” a few hundred meters above the ground. The average cold front is twice as steep as the average warm front. Moreover, cold fronts normally move faster than warm fronts because the dense, cold air mass easily displaces the lighter, warm air. This combination of steeper slope and faster advance leads to rapid lifting and adiabatic cooling of the warm air ahead of the cold front. The rapid lifting often makes the warm air very unstable, and the result is blustery and violent weather along the cold front. Vertically developed clouds, such as cumulonimbus clouds, are common, with considerable turbulence and showery precipitation. Both clouds and precipitation tend to be concentrated along and immediately behind the ground-level position of the front. Precipitation is usually of higher intensity but shorter duration than that associated with a warm front Warm Front: A warm front forms when a warm air mass is actively overriding a cold air mass. As warm air rises above cooler air, widespread cloudiness and precipitation develop along and in advance of the ground-level position of the front. Higher and less dense clouds are often dozens or hundreds of kilometers ahead of the ground-level position of the front. The slope of a typical warm front is more gentle than that of a cold front. As the warm air pushes against and rises over the retreating cold air, it cools adiabatically, usually resulting in clouds and precipitation. 3.7. Energy Resources: Almost all the developmental activities of modern society are directly or indirectly dependent upon energy. Energy consumption of a nation is usually considered as an index of its development. There is clear difference in per capita energy use between the developed and the developing nations. Utilization of energy probably first started when primitive man learnt to use fire which produced heat and the early man used it for cooking and heating purposes. Wind and hydropower have also been in use for the traditional society. The invention of steam engines replaced the burning of wood by coal and coal was later replaced to a great extent by oil. 3.7.1. Growing Energy Needs Modern society heavily relies upon various forms of energy. With growing populations, industrialization and other developmental sectors demands for energy is increasing world over. The fossil fuels like coal, oil and natural gas supply about 95% of the commercial energy in the world.  Our changing life style and quest for a more and more luxurious life has further increased the demand of energy. Increasing numbers of electric gadgets in our homes and rising number of cars in our localities demand increased amounts of energy with every passing day.  The consumption and demand of energy is much higher in developed countries. Countries like U.S.A. and Canada constitute only 5% of the world’s population but consume 25% of global energy resources. Energy consumption of a single person in these countries is about 300 GJ (Giga Joules) per year.  Whereas an average man in a poor country like Bhutan, Nepal or Ethiopia consumes less than 1 GJ in a year. So a person in a rich country consumes almost as much energy in a single day as one person does in a whole year in a poor country. This clearly depicts that our modernized way of life needs much more energy.  It indicates very high demands of energy in the world in future as the world as a whole is shifting from a simple way of life to a modern and sophisticated way of life. Thus, there is very high pressure on the existing conventional sources of energy. But, unfortunately, these sources of energy are not going to last forever. Worlds Growing Energy Needs 3.7.2. Growing Energy Needs ( Energy Scenario in India) (A) Energy Import India, though rich in coal and abundantly endowed with renewable energy in the form of hydro, wind, solar and bio-energy, has very small hydrocarbon reserves. India is a net importer of energy, more than 25% of primary energy needs being met through imports mainly in the form of natural gas and crude oil. (B) Energy Production Pattern Coal and oil account for 54% and 34% respectively, with natural gas, hydro, solar and nuclear contributing to the balance. Nearly 62% of power generation is from coal-fi red thermal power plants and 70% of the coal produced every year in India has been used for thermal power generation.  Energy Distribution in India (C) Distribution of Primary Commercial Energy Resources The distribution is non-uniform. The northern and north-eastern regions account for 70% of the total hydro potential, whereas the eastern region accounts for about 70% of the total coal reserves in India. The southern region has most of the lignite deposits in the country. (D) Energy-Consumption Pattern The industrial sector consumes about 52% of commercial energy production. The energy consumption per unit of GDP (energy intensity) is one of the highest in comparison to other developed and developing countries. Thus, there is a huge scope for energy conservation in India. (E) Future The long-term availability of energy from sources that are affordable, accessible and environmentally friendly will govern the future economic growth in India. (F) Over-exploitation of Energy Resource in India Power demand in India touched an all-time high of 99,027 MW recently, a year- on-year growth of over 16%. In our country, economic growth is very fast which is responsible for the growing energy demands of the country. India’s demand for energy is set to increase to as much as 415,000 MW by 2020 at an average GDP growth rate of 8% per year as per the forecast from Mckinsey and company in 2008. (F) Over-exploitation of Energy Resource in India To meet this energy requirement, the country has to overexploit all its energy resources. Presently the power needs of the country are primarily met by thermal power stations (about 60%), followed by hydro, wind and nuclear power stations. India is experiencing shortages in the production of domestic coal. Many of the thermal power stations, including NTPC, faced critical coal stock levels and had to cut down their production levels. The obvious result was power cut. In 2008–09 due to non-availability of power, India Inc. has supposedly lost `43,205 crore as pera study. The coal reserves of India may get exhausted by 2040 at the current rate of coal consumption. India may have to depend entirely on coal imports. (H) Problems due to Over-exploitation of Energy In the US, nonrenewable fossil fuels provide 92% of the energy used. The US has 3% of the world’s oil and petroleum resources, but consumes 25% of the crude oil extracted in the world. US citizens also waste tremendous amount of energy. Higher consumption of energy resources means larger emissions of greenhouse gases which lead to global warming and consequent problems. Many developing countries are striving to reach the level of prosperity of the US. It has been estimated that if world starts consuming at the same rate as the US, the world could run out of fossil fuels in a few years. Problems due to over-exploitation of energy resources 3.7.3. Sources of Energy A source of energy is a substance or means that can provide adequate amount of energy in a usable form over a long period of time. These sources can be of two types: A. Non-renewable Energy Resources Energy sources which have accumulated in nature over a long span of time and cannot be quickly replenished when exhausted e.g. coal, petroleum, natural gas and nuclear fuels like uranium and thorium. They are also known as conventional sources of energy B. Renewable Energy Resources Energy Sources which can generate energy continuously in nature and are inexhaustible or regenerable e.g. wood, solar energy, wind energy, tidal energy, hydropower, biomass energy, bio-fuels, geo-thermal energy and hydrogen. They are also known as non-conventional sources of energy and they can be used again and again in an endless manner. Important Energy Sources Differences between conventional and nonconventional sources of energies A. Non-Renewable Energy Resources i. Fossil Fuels: Fossil fuels like coal, petroleum and natural gas are the major sources of energy in the present world. They are used as fuels and are nonrenewable. These were formed by the decomposition of the remains of plants and animals buried under the earth millions of years ago. Nuclear energy is another form which is very effective but has also its own demerits. a. Coal: Coal is defined as stratified rock, consisting of organic matter of fuel value derived from the partial decay and alteration of accumulated plant materials by the action of heat and pressure over millions of years. India has about 5% of world’s coal though Indian coal is not very good in terms of heat capacity.  Coal is of the following four types: Major coal fields in India are Raniganj, Jharia, Bokaro, Singrauli, and Godavari valley. On burning coal causes serious environmental pollution including release of carbon dioxide a major green house gas, SO2, NOx, Ash, and Particulate matter. b. Petroleum: It is the most important energy source in the world. There are 13 countries in the world having 67% of the petroleum reserves which together form the OPEC (Organization of Petroleum exporting countries). About 1/4th of the oil reserves are in Saudi Arabia. Crude petroleum is a complex mixture of alkane hydrocarbons. Hence it has to be purified and refined by the process of fractional distillation, during whi