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Environmental Studies Unit 3: Natural Resources

Semester-2 Ability Enhancement Compulsory Course-2 (AECC-2) …………………………………………………

Compiled by Dr Harisadhan Ghosh

___________________________________________________________________________________ Calcutta University Syllabus: • Concept of Renewable and Non-renewable resources • Land resources and land use change; Land degradation, soil erosion and desertification. • Deforestation: Causes, consequences and remedial measures • Water: Use and over-exploitation of surface and ground water, floods, droughts, conflicts over water

(international & inter-state). • Energy resources: Environmental impacts of energy generation, use of alternative and nonconventional

energy sources, growing energy needs. ___________________________________________________________________________________ Renewable and Non-Renewable Resources: - Natural Resources are, all of the Earth’s organisms, such as air, water, soil and the materials which are removed from the ground like oil, coal and various ores. These resources cannot be produced by our man-kind. Natural Resources can be classified in two broad categories-

1. Renewable Resources 2. Nonrenewable Resources

1. Renewable Resources Resources that can be replenished (i.e replaced) naturally in the course of time are called Renewable Resources. Examples:

(i) Wind–caused by the uneven heating of the Earth Not only renewable but in exhaustible. (ii) Water–constantly renewed/replenished by the water cycle. (iii) Sun–light from the sun supports all the life on Earth as we know it. Also considered

inexhaustible. (at least for the next 5 billion years) Besides that, other Renewable Resources are-

(iv) Soil–a mixture of living organisms and dirt. Even though it initially takes thousands of years to form, the rate at which soil can regenerate depends on the climate of an area.

(v) Food and fiber–are renewable agricultural resources that can be harvested or raised indefinitely unless their use exceeds the rate they can be replaced

2. Non-renewable Resources Resources that exist in limited supply and cannot be replaced if they are used up are called Non-Renewable Resources. They took thousands of years to form and exist in fixed amounts in the Earth and need to be conserved before they become depleted.

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Examples: (i) Ores-Ores are mineral deposits from which valuable metals and nonmetals can be recovered

for profit. Metallic ores include: gold, silver, copper, aluminum, zinc, etc. Non-metallic ores include: salt, sand, gravel, clay, diamonds, gemstones, etc.

(ii) Fossil Fuels- They are nonrenewable because they take thousands of years to form. In developing countries, the fossil fuels are fossilized wood, charcoal, and peat. In developed countries, the fossil fuels are mainly coal, natural gas, and oil.

(iii) Coal– It is the remains of wetland plants that have been compressed over millions of years. Different types of coal are- Peat, Lignite, Bituminous, Anthracite.

(iv) Petroleum and Natural Gas–They are the remains of mainly marine organisms. …………………………………………………………………………………………………………… Land Resources:- Land is among the most important natural resources. It covers up only 29% of the earth’s surface and all parts of the land are not habitable. The uneven distribution of population in different parts of the world is mainly due to varied characteristics of land and climate. § Uses of Land:

1. For Residential and for Construction purpose. 2. For the construction of roads. 3. For Agricultural and for Gardening purpose. 4. For creating Forests. 5. For the construction of big Industrial Units. 6. For preparing canal and water resources.

§ Misuses of Land: 1. Destruction of forests. 2. Unused grass land. 3. Non planned urbanization. 4. Excess use of chemical fertilizers. 5. Use of land for mineral industries.

Land Resources in India: -

Soil Erosion:

Soil erosion is a naturally occurring process that affects all landforms. In agriculture, soil erosion refers to the wearing away of a field's topsoil by the natural physical forces of water. Erosion, whether it is by water, wind or tillage, involves three distinct actions – soil detachment, movement and deposition. Topsoil, which is high in organic matter, fertility and soil life, is relocated elsewhere "on-site" where it builds up over time or is carried "off-site" where it fills in drainage channels.

Land resources in India

• Land Resources in India

enclose approximately 1.3

million sq. miles and is a cape,

protruding into the

Indian Ocean, in between the

Bay of Bengal on the east and

Arabian Sea on the west.

Indian land resources are

segmented into varied relief

features, 43% of land area is

plain region; Indian mountain

region constitutes 30% of the

area, where as plateaus

account for 27 % of the total

surface area on the nation.

Land resources in India

• Land Resources in India

enclose approximately 1.3

million sq. miles and is a cape,

protruding into the

Indian Ocean, in between the

Bay of Bengal on the east and

Arabian Sea on the west.

Indian land resources are

segmented into varied relief

features, 43% of land area is

plain region; Indian mountain

region constitutes 30% of the

area, where as plateaus

account for 27 % of the total

surface area on the nation.

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Causes of Erosion- The main cause of soil erosion is the removal of vegetation. Vegetation removal takes place due to removal of forest covers. Unscientific farming has also led to barren lands. The removal of vegetation exposes the topsoil to water and wind. Water and wind cause the topsoil to be removed. Water Erosion: Removal of topsoil by water is called water erosion. It takes place in the following ways: • Sheet erosion • Rill erosion • Gully erosion • Riparian erosion Sheet Erosion: The removal of the entire topsoil as a result of heavy rains is called sheet erosion. Rill Erosion: Runoff water moves across the soil forming small streams. The topsoil is removed only in these rills formed by the water streams. Gully Erosion: Deep depressions called the gullies are formed by swiftly moving waters causing soil erosion by them. Riparian Erosion: The banks of rivers lose top soil due to the action of the fast moving rivers waters.These waters remove the underlying Prevention & Control of Soil Erosion- • Increase of Vegetation

When the land is covered with vegetation, the roots of the plants and trees interlock and interlace to bind the soil particles. This helps in two ways:

• does not allow the soil particles to be carried away by wind or water • does not allow free flow of water over the soil which prevent erosion of soil by flowing water • the falling leaves of the plants get converted to humus by decomposing action of the soil microbes.

This enriches the soil. Several methods can be employed to increase the vegetation cover of land. Some of them are as follows: • Crop Rotation- The practice of growing different crops at different times on the same land is called crop rotation. This keeps the topsoil covered with vegetation. Rotation of cereal crops with legumes also keeps the soil enriched with nitrogen (from the legumes). • Reforestation- Slopes are more subject to soil erosion by running water. Growing trees on lands which have lost their vegetation is called reforestation. Trees like Albizia, Cassia, Butia, etc. are suitable for this. • Strip Cropping- It involves growing of crops in strips. The most common method followed is the contour farming where the strips of crop are at right angles to the slope. Wind-strip cropping is when the strips of crop are place at right angles to the direction of wind. • Restoring Soil Fertility- Fertile soil supports vegetation. Loss of fertility results in loss of vegetation and this exposes the land to erosion. Fertility of soil can be increased by addition of natural and synthetic fertilizers.

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• Control of Grazing- Covering the land with small plants and grasses helps the topsoil to remain in place as the roots of these plants bind with the soil particles. Cattle graze on these plants and expose the topsoil Thus, grazing should be allowed only on the land meant for the purpose and other areas should be protected from grazing. • Terracing- Fields are cut at right angles to the slope. This slows down the flowing water and allows it to irrigate the crops, as well. • Dam Building With the dams the speed and amount of water flowing can be controlled. This will control the soil erosion of the river banks. • Wind Breakers Trees are planted across the wind direction to protect against the high velocity winds. These rows of trees are called shelter belts or wind breakers

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Desertification: Desertification is a type of land degradation in drylands in which biological productivity is lost due to natural processes or induced by human activities whereby fertile areas become increasingly more arid. It is the spread of arid areas caused by a variety of factors, such as through climate change(particularly the current global warming) and through the overexploitation of soil through human activity.

When deserts appear automatically over the natural course of a planet's life cycle, then it can be called a natural phenomenon; however, when deserts emerge due to the rampant and unchecked depletion of nutrients in soil that are essential for it to remain arable, then a virtual "soil death" can be spoken of, which traces its cause back to human overexploitation. Desertification is a significant global ecological and environmental problem with far reaching consequences on socio-economic and political conditions.

Cause of desertification: Overgrazing of drylands by poorly managed traditional herding is one of the primary causes of desertification. Overgrazing is not necessarily caused by nomadic grazers in large travelling herd populations. The immediate cause is the loss of most vegetation. This is driven by a number of factors, alone or in combination, such as drought, climatic shifts, tillage for agriculture, overgrazing and deforestation for fuel or construction materials. Vegetation plays a major role in determining the biological composition of the soil. Studies have shown that, in many environments, the rate of erosion and runoff decreases exponentially with increased vegetation cover. Unprotected, dry soil surfaces blow away with the wind or are washed away by flash floods, leaving infertile lower soil layers that bake in the sun and become an unproductive hardpan. Many scientists think that one of the most common causes is overgrazing, too much consumption of vegetation by cattle or other livestock.

Scientists agree that the existence of a desert in the place where the Sahara deserts is now located is due to a natural climate cycle; this cycle often causes a lack of water in the area from time to time. There is a suggestion that the last time that the Sahara was converted from savanna to desert it was partially due to overgrazing by the cattle of the local population.

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Overpopulation is one of the most dangerous factors contributing to desertification. Human populations are increasing at exponential rates, which leads to overgrazing, over-farming and deforestation, as previously acceptable techniques are becoming less sustainable.

Climate change is likely a major contributing factor in the desertification process, as simulations suggest the greenhouse effect may increase the spread of deserts by as much as 20%.

There are multiple reasons farmers use intensive farming as opposed to extensive farming but the main reason is to maximize yields. By increasing productivity, they require a lot more fertilizer, pesticides, and labor to upkeep machinery. This continuous use of the land rapidly depletes the nutrients of the soil causing desertification to spread.

Effect of desertification:

Sand and dust storms-

There has been a 25% increase in global annual dust emissions between the late nineteenth century to present day. The increase of desertification has also increased the amount of loose sand and dust that the wind can pick up ultimately resulting in a storm. For example, dust storms in the Middle East “are becoming more frequent and intense in recent years” because “long-term reductions in rainfall promot[ing] lower soil moisture and vegetative cover”.

Dust storms can contribute to certain respiratory disorders such as pneumonia, skin irritations, asthma and many more. They can pollute open water, reduce the effectiveness of clean energy efforts, and halt most forms of transportation.

Dust and sand storms can have a negative effect on the climate which can make desertification worse. Dust particles in the air scatter incoming radiation from the sun. The dust can provide momentary coverage for the ground temperature but the atmospheric temperature will increase. This can disform and shorten the life time of clouds which can result in less rainfall.

Food security-

Global food security is being threatened by desertification and overpopulation. The more the population grows, the more food that has to be grown. The agricultural business is being displaced from one country to another. For example, Europe on average imports over 50% of its food. Meanwhile, 44% of agricultural land is located in dry lands and it supplies 60% of the world's food production. Desertification is decreasing the amount of sustainable land for agricultural uses but demands are continuously growing. In the near future, the demands will overcome the supply.

Vegetation patterning

As the desertification takes place, the landscape may progress through different stages and continuously transform in appearance. On gradually sloped terrain, desertification can create increasingly larger empty spaces over a large strip of land, a phenomenon known as "brousse tigrée". A mathematical model of this phenomenon proposed by C. Klausmeier attributes this patterning to dynamics in plant-water interaction. One outcome of this observation suggests an optimal planting strategy for agriculture in arid environments.

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Deforestation:

The earth’s land area where the vegetations are grown naturally in groups is known as a forest. Vegetations means trees, shrubs, creepers or any woody vegetations having a closed canopy.

Classification of Indian Forests

1. Evergreen forests. 2. Deciduous forests 3. Dry forests 4. Mountain or Hill forests 5. Tidal forests

Reasons for Deforestation

1. For obtaining raw materials for industry. 2. For obtaining timber for furniture and construction work. 3. For obtaining fire wood. 4. For developing the mineral industry. 5. For constructing projects on rivers. 6. For expanding Agricultural land. 7. For the purpose of constructing the roads. 8. For establishing industries. 9. For the construction of railway tracks. 10. Human accommodation. 11. Over grassing of forest by live stocks. 12. Destruction by insects and pests. 13. Forest fires. 14. Extreme weather conditions.

Threats associated with Deforestation:

1. Increase in the possibilities of flash floods. 2. Decrease in the rain fall. 3. Increase in the atmospheric temperature. 4. Increase in the amount of soil erosion. 5. Migration of tribal population leads to mental frustration. 6. Extinction of some useful medicinal species. 7. Shelter problem for forest animals will increase. 8. Problem of urbanization will arise. 9. Atmosphere will become adverse. 10. Desertification of forests and agricultural land. 11. Forest dwellers will have a problem of survival. 12. Decrease in the population of animal species. 13. Increased chances of cyclone due to climate change.

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Need and measures of Forest Conservation:

Needs:

1. To maintain equilibrium in Ecosystem. 2. To maintain Bio-diversity.

Measures:

1. Forest fires should be prevented. 2. Use of pesticides to eliminate the risk of pests. 3. Plantation of resistant varieties. 4. Replacements of trees (aforestation) 5. Replacing the fire woods by biogas and solar cooker. 6. Implementation of social forestry programmes. 7. Aforestation programmes should be undertaken on wastelands. 8. Trees of aesthetic value should be planted. 9. Renewal of forest crops. 10. Reforestation by suitable monoculture. 11. Unwanted felling of trees should be restricted.

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Water Resources:

Water is a vital elixir for all living beings. Although it is a renewable resource, scarcity of quality water is felt in many parts of the world. We need water to grow food, keep clean, generate electricity, control fire, and last but not the least, we need it to stay alive.

Water Cycle

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World Ocean water covers about 75 percent of the surface of the earth. Therefore, the earth is called the water planet. Ocean water is saline and not fit for human consumption. Fresh water is just about 2.7 percent of the total water. Global warming and perpetuating water pollution have made a considerable part of available freshwater unfit for human consumption. As a result, water is very scarce.

Steps need to be taken to conserve water. Water is renewable, but its overuse and pollution make it unfit for use. Sewage, industrial use, chemicals, etc. pollute water with nitrates, metals, and pesticides.

Use of Water Resources

Water resources are used for agricultural, industrial, domestic, recreational, and environmental activities. Majority of the uses require fresh water.

However, about 97 percent of water found on the earth is salt water and only three percent is fresh water. A little over two-thirds of the available fresh water is frozen in glaciers and polar ice caps. The remaining freshwater is found mainly as groundwater and a negligible portion of it is present on the ground or in the air.

Following is a brief account of how water is used in different sectors.

Agricultural Use

Agriculture accounts for 69 percent of all water consumption basically in agricultural economies like India. Agriculture, therefore, is the largest consumer of the Earth’s available freshwater.

By 2050, the global water demand of agriculture is estimated to increase by a further 19% due to irrigational needs. Expanding irrigation needs are likely to put undue pressure on water storage. It is still inconclusive whether further expansion of irrigation, as well as additional water withdrawals from rivers and groundwater, will be possible in future.

Industrial Use

Water is the lifeblood of the industry. It is used as a raw material coolant, a solvent, a transport agent, and as a source of energy. Manufacturing industries account for a considerable share in the total industrial water consumption. Besides, paper and allied products, chemicals and primary metals are major industrial users of water.

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Worldwide, the industry accounts for 19 percent of total consumption. In industrialized countries, however, industries use more than half of the water available for human use.

Domestic Use

It includes drinking, cleaning, personal hygiene, garden care, cooking, washing of clothes, dishes, vehicles, etc. Since the end of World War II there has been a trend of people moving out of the countryside to the ever-expanding cities. This trend has important implications on our water resources.

Government and communities have had to start building large water-supply systems to deliver water to new populations and industries. Of all water consumption in the world, domestic use accounts for about 12 percent.

Use for Hydropower Generation

Electricity produced from water is hydropower. Hydropower is the leading renewable source of electricity in the world. It accounts for about 16 percent of total electricity generation globally. There are many opportunities for hydropower development throughout the world.

Today, the leading hydropower generating countries are China, the US, Brazil, Canada, India, and Russia.

Use for Navigation and Recreation

Navigable waterways are defined as watercourses that have been or may be used for transport of interstate or foreign commerce. Agricultural and commercial goods are moved on water on a large scale in a number of regions in the world.

Water is also used for recreational purposes such as boating, swimming, and sporting activities. These uses affect the quality of water and pollute it. Highest priority should be given to public health and drinking water quality while permitting such activities in reservoirs, lakes, and rivers.

Overutilization of Surface and Ground Water

Water scarcity has become a burning global issue. The UN has held several conventions on water in recent decades. Continuous overutilization of surface and ground water has led to virtual water scarcity in the world today.

The depleting sources for high growth in human population over the centuries and increased man-induced water pollution across the world have created unforeseen water scarcity around the globe. As a result, there has been continuous overutilization of the existing water sources due to mammoth growth in world population.

Groundwater is the major source of water in many parts of the world. However, there has been continuous depletion of this source due to its overexploitation by rising human population and the rapid rise in industrialization and urbanization in modern times.

Consequences of Overutilization

Water scarcity now becomes an important topic in international diplomacy. From village to the United Nations, water scarcity is a widely-discussed topic in decision making.

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Nearly three billion people in the world suffer from water scarcity. International, intrastate and regional rivalries on water are not new to world. The ongoing Jordan River conflict, Nile River conflict, and Aral Sea conflict are cases in point. The intra-state issues such as Cauvery Water dispute in South India, 2000 Cochabamba protests in Bolivia is still a simmering cauldron causing periodic tension at the national and regional levels.

According to World Health Organization (WHO) sources, a combination of rising global population, economic growth and climate change means that by 2050 five billion (52%) of the world’s projected 9.7 billion people will live in areas where fresh water supply is under pressure. Researchers expect about 1 billion more people to be living in areas where water demand exceeds surface-water supply.

Climate Change

Scientists, environmentalists, and biologists worldwide are now alarmed that climate change can have an impact on the drainage pattern and hydrological cycle on the earth thereby severely affecting the surface and groundwater availability.

Climate change is believed to rise the global temperature at an increasing pace. Temperature increase affects the hydrological cycle by directly increasing evaporation of available surface water and vegetation transpiration.

As a result, precipitation amount, timing and intensity rates are largely affected. It impacts the flux and storage of water in surface and subsurface reservoirs.

Floods & Draughts

Floods and droughts are two well-known natural hazards in the world. The former is due to excess in water flow and the latter is due to scarcity of water.

The amount of rainfall received by an area varies from one place to another depending on the location of the place. In some places it rains almost throughout the year whereas in other places it might rain for only few days. India records most of its rainfall in the monsoon season.

Heavy rains lead to rise in the water level of rivers, seas, and oceans. Water gets accumulated in the coastal areas, which results in floods. Floods bring in extensive damage to crops, domestic animals, property and human life. During floods, many animals get carried away by the force of water and eventually die.

On the other hand, droughts set in when a particular region goes without rain for a long period of time. In the meantime, the soil will continuously lose groundwater by the process of evaporation and transpiration. Since this water is not brought back to earth in the form of rains, the soil becomes very dry.

The level of water in the ponds and rivers goes down and in some cases water bodies get dried up completely. Ground water becomes scarce and this leads to droughts. In drought conditions, it is very difficult to get food and fodder for the survival. Life gets difficult and many animals perish in such conditions.

Frequent floods and droughts are mostly due to climate change and global warming. Various environmental organizations world over are of the view that climate change is a long-term change in weather patterns, either in average weather conditions or in the distribution of extreme weather events.

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Recharging and Conservation of Water:

1. Construction of small Dams and artificial lakes for the water storage purpose. 2. Construction of ponds for the purpose of storing rain water. 3. Grow more trees to increase the chances of Rain. 4. Economical use of water. (avoid water wastage) 5. Try to reuse the water. e.g:

(a) water used for bathing can be reused for vegetation in the veranda. (b) reuse of water by spraying it on dusty roads to prevent small particles to mix with air.

6. Use based water charges for controlling water usage. 7. After purification of Dirty water it should be used in farms or grass lands.

Conflicts over water (international & inter-state):-

Water conflict is a term describing a conflict between countries, states, or groups over an access to water resources. Inter-state Water Conflict: India mainly depends on Agriculture. There are multi purposes projects and irrigation projects constructed across the rivers for the efficient supply of water for the agricultural purposes. So, the sharing of river water resources plays an important role for the welfare of the people The inter sate water disputes arising among the states in sharing the river water. Many river water disputes have erupted since Indian independence. As per the Inter-State River Water Disputes Act, 1956 (ISRWD Act, 1956) when the water dispute arises among two or more State Governments, the Central Government receives a request under Section 3 of the Act from any of the basis States with regard to existence of water dispute. The status of such inter-State water disputes under ISRWD Act, 1956 is shown below

Source : Ministry of Water Resources, Govt of India

River(s) States Date of Constitution of Tribunal

Date of Award

Krishna Maharashtra, Karnataka, Andhra Pradesh

April 1969 May 1976

Godavari Maharashtra, Andhra Pradesh, Karnataka, Madhya Pradesh, Orissa

April 1969 July 1980

Narmada Rajasthan, Madhya Pradesh, Gujarat, Maharashtra

October 1969 December 1979

Cauvery Karnataka, Kerala,Tamil Nadu and union territory of Pondicherry

June 1990 Febrauary 2013

Krishna Maharashtra, Karnataka, Andhra Pradesh

April 2004 December 2010

Model/Mandovi/ Mahadayi

Goa, Karnataka and Maharashtra

November 2010 Pending

Vansadhara Andhra Pradesh, Orissa

June 2009 Pending

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Kaveri river water dispute (Karnataka and Tamil Nadu):- The genesis of this conflict rests in two agreements in 1892 and 1924 between the erstwhile Madras Presidency and Princely State of Mysore Karnataka contends that it does not receives its due share of water from the river. It claims that the agreements were skewed heavily in favour of the Madras Presidency and has demanded a renegotiated settlement based on equitable sharing of the water. Tamil Nadu, on the other hand plead that it has already developed almost 3,000,000 acres of land and so has come to depend very heavily on the existing pattern of usage. Any change, will adversely affect the livelihood of millions of families in the state. The Government of India gave final verdict on 5th February 2007, allocated 419 billion cubic feet of water annually to Tamil Nadu and 270 billion cubic feet to Karnataka; 30 billion cubic feet of Kaveri river water to Kerala and 7 billion cubic to Puducherry. All four states deciding to file review petitions seeking clarifications and possible renegotiation of the order. On 20 February 2013, based on the directions of the Supreme Court, the Indian Government has notified the final award of the Cauvery Water Disputes Tribunal (CWDT). The Supreme Court on 10 May 2013 issued an interim direction to the Government of India to establish a temporary. Supervisory Committee to implement the Cauvery Tribunal order.

International Water Conflict:-Tsangpo-Brahmaputra (Indo – China conflict) China’s grand plans to harness the waters of the Brahmaputra River have set off ripples of anxiety in the two lower riparian countries- India and Bangladesh. China’s construction of dams and the proposed diversion of the Brahmaputra’s waters is expected to have repercussions for water flow, agriculture, ecology, and lives and livelihoods downstream. The Chinese government has approved hydropower projects along the Brahmaputra. It maintains that all these are run-of-the-river projects that involve no storage or diversion and that they will not affect the river’s downstream flow into northeast India. Still, its plans have generated apprehensions in India’s Northeast and in Bangladesh, where the Brahmaputra is a veritable lifeline. More worrying than China’s construction of hydropower dams on the Brahmaputra is the proposed northward rerouting of its waters. This diversion would result in a significant drop in the river’s water level as it enters India. It will have a serious impact on agriculture and fishing in the downstream areas as the salinity of water will increase. The lack of communication on the issue is deepening suspicion and tension. This underscores the need for dialogue that includes all the riparian countries. China must share data on its dam construction and other plans for the Brahmaputra. ……………………………………………………………………………………………………………...

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Energy Resources: -

“Energy” Meaning:

o Energy is the amount of force or power when applied can move one object from one position to another. o Energy defines the capacity of a system to do work. o Energy exists in everybody whether they are human beings or animals or non-living things e.g: Jet, Light, Machines etc. o Energy is intimately related to power. o According to the law of conservation of energy, any form of energy can be converted into another form, the total energy will remain the same. For example: when you charge your mobile phone the electrical energy is converted into the chemical energy which gets stored inside the battery.

Energy and Environment:-

Ø Energy and environment have a strong relationship. The production and consumption of energy is one of the biggest causes of environmental damage on earth. Ø It leads to large amounts of destruction of natural landscapes and habitants through the process of fuel extraction, pollution of soil, climate change, etc. Ø Energy is at the heart of many of the world’s current environmental problems, and posses many problems for the sustainable development. Renewable Energy:-

Ø Renewable energy is energy which is generated from natural sources i.e. sun, wind, rain, tides and can be generated again and again as and when required. Ø They are available in plenty and by far most the cleanest sources of energy available on this planet. Ø Renewable technologies are suited to large-scale production small off grid applications Main forms of renewable energy:- § Wind energy § Hydro energy § Solar energy § Bio-fuel § Geothermal energy

Wind Power

• Air flows can be used to run wind turbines. • Areas where winds are stronger and more constant, such as offshore and high altitude sites, are

preferred locations for wind farms. • Wind energy is believed to be five times total current global energy production, or 40 times current

electricity demand.

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• This could require large amounts of land to be used for wind turbines, particularly in areas of higher wind resources. Offshore resources experience wind speeds of ~90% greater than that of land.

• Wind power produces no greenhouse gases during operation, and power is growing at the rate of 30% annually, with a worldwide installed capacity of 157,900 MW.

Solar energy

§ Solar energy is the energy derived from the sun through the form of solar radiation. § Solar powered electrical generation relies on photovoltaic and heat engines. A partial list of other solar applications include day lighting, solar hot water, solar cooking and high temperature process heat for industrial purposes. § Solar technologies are broadly characterized as either passive solar or active solar depending on the way they capture, convert and distribute solar energy.

Ø Active solar techniques include the use of photovoltaic panels and solar thermal collectors to harness the energy. Ø Passive solar techniques include orienting a building to the Sun, selecting materials with favourable thermal mass or light dispersing properties, and designing spaces that naturally circulate air.

Advantages of Renewable resources § Wide availability §Lower running cost § Decentralized power production § Low pollution § Available for the foreseeable future Disadvantages of Renewable Resources: § Unreliable supply § Usually produced in small quantities § Often very difficult to store § Currently per unit cost of energy is more compared to other types

Non-Renewable Energy Resources:- A non-renewable resource is a natural resource that cannot be re-made or re-grown at a scale comparable to its consumption.

• Nuclear Energy • Coal, Petroleum, and Gas • Fossil Fuels

Advantages of Non-renewable Resources: • Available in highly concentrated form • Easy to store • Reliable supply • Lower cost per unit of energy produced as the technology is matured

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Disadvantages of Non-renewable resources:-

• When coal is burnt it produces carbon dioxide that causes global warming. • Since coal contains impurities like S and N, it produces toxic gases during burning which causes

acid rain and air pollution. § Traces of mercury and radioactive compounds are also released when coal is burned. § Severe human health threat.(lung disease)

Use of Alternate Energy Sources:- There is a need to develop renewable energy sources which are available and could be utilized (solar or wind) or the sources which could be created and utilized (bio-mass). The main renewable energy sources for India are solar, wind, hydel, waste and bio-mass. Bio-mass are resources which are agriculture related like wood, bagasse, cow dung, seeds, etc. Hydel energy India has a total hydro energy potential of about 1.5 lakh MW, of which only about 20% is installed. Small hydro plant potential is about 15000 MW and most of it is in the northern and eastern hilly regions. Wind energy The wind power potential of India is about 45,000 MW out of which capacity of 8748 MW has been installed in India till 2008. India is one of the leading countries in generating the power through wind energy. Gujarat, AP, Karnataka, MP and Rajasthan are states having more than 5000 MW potential each. These potentials could be improved if the technology of putting turbines in sea is embraced. There are wind farms on sea generating as high as 160 MW of power. Geothermal energy Geothermal energy is thermal energy generated and stored in the Earth. Thermal energy is the energy that determines the temperature of matter. Earth's geothermal energy originates from the original formation of the planet (20%) and from radioactive decay of minerals (80%). Geothermal power is cost effective, reliable, sustainable, and environmentally friendly, but has historically been limited to areas near tectonic plate boundaries. Recent technological advances have dramatically expanded the range and size of viable resources, especially for applications such as home heating, opening a potential for widespread exploitation. Geothermal wells release greenhouse gases trapped deep within the earth, but these emissions are much lower per energy unit than those of fossil fuels. As a result, geothermal power has the potential to help mitigate global warming if widely deployed in place of fossil fuels. Ocean thermal energy conversion (OTEC) Ocean Thermal Energy Conversion (OTEC) uses the difference between cooler deep and warmer shallow or surface ocean waters to run a heat engine and produce useful work, usually in the form of electricity. A heat engine gives greater efficiency and power when run with a large temperature difference. In the oceans the temperature difference between surface and deep water is greatest in the tropics, although still a modest 20 to 25 °C. It is therefore in the tropics that OTEC offers the greatest possibilities. OTEC has the potential to offer global amounts of energy that are 10 to 100 times greater than other ocean energy options such as wave power.

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Biomass energy Biomass is the oldest means of energy used by humans along with solar energy. As soon as the fire was discovered, it was used widely among humans mainly for heat and light. Fire was generated using wood or leaves, which is basically a biomass. The biomass could be used to generate steam or power or used as a fuel. Power is generated using rice husk in Andhra Pradesh, while several bagasse based plants are there. India has a potential of 3500 MW from bagasse. Other fast growing plants could be planned over a huge area, so that it provides biomass for generating power. Organic waste such as dead plant and animal material, animal dung, and kitchen waste can be converted by the anaerobic digestion or fermentation into a gaseous fuel called biogas. Biogas is a mixture of 65% methane (CH4) and of 35% CO2 and may have small amounts of hydrogen sulphide (H2S), moisture and siloxanes. It is a renewable energy resulting from biomass. Biogas can be used as a fuel in any country for any heating purpose, such as cooking. It can also be used in anaerobic digesters where it is typically used in a gas engine to convert the energy in the gas into electricity and heat. Biogas can be compressed, much like natural gas, and used to power motor vehicles. Bio-fuels India has more than 50 million hectare of wasteland, which could be utilized for cultivating fuel plants. Jatropha is one of the options which can be planted on arid lands and be used for production of bio fuels. Solar energy India being a tropical country has potential to use solar energy on commercial bases. According to estimates, 35 MW of power could be generated from one sq km. With such potential, solar energy has bright future as energy source for the development of the country. Initial cost is the biggest limitation which has led to the low realization of its potential. For solar energy to become one of the front runners, it will require lot of research, cheap technology and low capital. Problems Relate To the Use of Energy Resources

1. Fossil fuel • Global warming • Acid rains • Dangers posed by leaded fuels ,Oil spills • Water pollution caused by poorly managed coal mines • Air pollution.

2. Alternate energy resources-

• The initial cost of establishment of alternate energy generation is costlier than conventional resources

• Maintenance of these structures is difficult. • It requires more space. • Energy supply is unpredictable during natural calamities.

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Demand for “Energy Resources”: Importance of the energy resources in present economy and as a base for our future can be underlined by the fact that recent confrontations between some powerful nations of the world have primarily been attributed driven by objective to secure their energy supplies. Examples of this have been the two gulf wars. It was the hunger for energy resources that drove Iraq to lead an offensive over Kuwait and also reason for second Gulf war has been attributed to energy security by defence experts. In recent times, world has witnessed a confrontation at South China Sea between India, Vietnam and China over the issue of exploring natural gas and petroleum under the sea bed.

References: Various Internet Sources such as Wikipedia, Slide Share and Journals.

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Natural Resources-MCQ

1. What is a natural resource?

a. A natural resource is anything found in nature.

b. A natural resource is a small cabin in the woods.

c. A natural resource is something that lives outdoors.

d. A natural resource is something found in nature that people use.

2. What is a renewable natural resource?

a. A natural resource that can regrow or be replaced in a person’s life span.

b. A natural resource that is used up quickly and not replaced

c. A natural resource that can never be replaced in a person’s life span.

d. A natural resource that can be recycled, like glass and paper

3. What does recycling mean?

a. To use a natural resource to make something new.

b. To use less of a natural resource than is possible.

c. To reuse natural resources or old products to make new things

d. To put old products in the trash.

4. Soil erosion can be prevented by

(a) Raising forests

(b) Deforestation

(c) Excessive use of fertilizer

(d) Overgrazing by animals

5. What happens when rain falls on soil without vegetational cover?

(a) Rain water percolates in soil efficiently

(b) Rain water causes loss of surface soil

(c) Rain water leads to fertility of the soil

(d) Rain water does not cause any change in soil

6. Total earth’s surface covered by water is

(a) 75%

(b) 60%

(c) 85%

(d) 50%

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7. Top-soil contains the following

(a) Humus and living organisms only

(b) Humus and soil particles only

(c) Humus, living organisms and plants

(d) Humus, living organisms and soil particles.

8. Biogas is which type of natural resources-

(a) Renewable (b) Inexhaustible (c) Non-conventional (d) Both(a) and(c)

9. An inexhaustible and renewable source of energy is

(a) Wood (b) Natural gas (c) Fossil fuel (d) Hydropower

10. An exhaustible renewable resource is-

(a) Coal (b) Solar energy (c) Fresh water (d) Petroleum

11. A renewable exhaustible natural resource is-

(a) Forest (b) Coal (c) Petroleum (d) Minerals

12. Deforestation brings about-

(a) Soil erosion (b) Weed control (c) Decreases drought (d) Increased sunlight

13. Deforestation is caused due to

(a) Silviculture (b) Construction of roads (c) Rainfall (d) Plantation of trees

14 Deforestation is the major causal agent of

(a) Depletion of natural resources (b) Environmental pollution (c) Desertification of habitat

(d) Genetic erosion

15. Deforestation will decrease

(a) Soil erosion (b) Landslides (c) Soil fertility (d) Rainfall

16. Maximum use of fresh water is in

(a) Agriculture (b) Domestic use (c) Industry (d) Pisciculture

17. Reforestation is

(a) Plantation of forests (b) Plantation forests in deforested areas (c) Cutting down of forest

(d) Management of forest

18. Resources which are available in unlimited quantity are

(a) National resources (b) Exhaustible resources (c) Inexhaustible resources (d) Natural

resources

19. Solar energy is which type of natural resources

(a) Renewable (b) Non-renewable (c) Exhaustible (d) Inexhaustible

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20. The natural resources which are continuously consumed by man but are replenished by

nature with a reasonable period of time is called

(a) Exhaustible (b) Inexhaustible (c) Exhaustible renewable (d) Exhaustible non-renewable

21. There is decrease in _____ because of deforestation

(a) Soil erosin (b) Global warming (c) Rainfall (d) Drought

22. Which has caused maximum damage to Indian forests

(a) Selective harvesting (b) Block cutting (c) Taungya cultivation (d) Jhum cultivation

23. Which of the following acts as a main source of ground water?

(a) Rain (b) River (c) Ocean (d) Canals

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