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An overview of natural resources, their classification, examples, and the importance of their conservation. It covers various types of natural resources such as energy, forest, water, land, and mineral resources. The document also discusses renewable and non-renewable resources and their respective advantages and disadvantages. Additionally, it highlights the impact of human activities on water resources and land degradation, and the role of individuals in conserving natural resources.
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Unit-2 Natural Resources and Biodiversity Natural resources- occur naturally within environments that exist relatively undisturbed by mankind, in a natural form. Any component of the natural environment that can be utilized by human beings for their benefit are termed as natural resource. The natural resource can be a substance, an energy unit or a natural process or phenomena e.g. water, air, soil, minerals, coal, forests, crops, and wildlife are all examples of natural resources.
Natural resources are derived from the environment. Some of them are essential for our survival while most are used for satisfying our wants.
There are various methods of categorizing natural resources, these include source of origin, stage of development, and by their renewability, these classifications are described below-
such as uranium, which naturally decay into heavy metals. Of these, the metallic minerals can be re-used by recycling them, but coal and petroleum cannot be recycled. The major natural resources are: •.1. Energy resources •.2. Forest resources •.3. Water resources •.4. Land resources •.5. Mineral resources •.6. Food resources
Energy Resources: Sources from which energy can be obtained to provide heat, light, and power. Sources of energy have evolved from human and animal power to fossil fuels, uranium, water power, wind, and the Sun. The principal fossil fuels are coal, lignite, peat, petroleum, and natural gas. Energy consumption is an index of advancement of a country.
It can be classified as renewable/ non-renewable, conventional/ non-conventional, traditional/ alternative.
i. Renewable/ Non-renewable
Renewable Energy - energy sources which are in-exhaustive and can be regenerated within a given span of time such as sunlight, wind, rain, tides, and geothermal heat. Renewable energy is an alternative to fossil fuels and therefore commonly called alternative energy.
Non-renewable Energy- Energy sources which are exhaustible and cannot be regenerated within a given span of time such as fossil fuel like coal, petroleum, minerals etc.
ii. Conventional/ Non-conventional
Conventional Sources of Energy
(i) The sources of energy which have been in use for a long time, e.g., coal, petroleum, natural gas and water power.
(ii) They are exhaust able except water.
(iii) They cause pollution when used, as they emit smoke and ash.
(iv) They are very expensive to be maintained, stored and transmitted as they are carried over long distance through transmission grid and lines.
Non-Conventional Sources of Energy
(i) The resources which are yet in the process of development over the past few years. It includes solar, wind, tidal, biogas, and biomass, geothermal.
(ii) They are inexhaustible.
(iii) They are generally pollution free.
(iv) Less expensive due to local use and easy to maintain.
iii. Traditional/ Alternative
Advantages of solar Energy:
•.i. It is free of cost.
•.ii. Its supplies are unlimited.
•.iii. It does not produce air or water pollution.
Disadvantages of Solar Energy:
i. It has indirect impacts on the environment.
ii. Large solar thermal farms can harm the desert ecosystems if not managed properly.
iii. The amount of sunlight that arrives at the earth’s surface is not constant. It depends on the location, time of day, time of year and weather conditions.
iv. Since sun doesn’t deliver much energy to a specific place at a specific time, a large surface area is required to collect the energy at a useful rate.
According to International Energy Agency Report 2016, the top ten countries in Installed Solar Power Capacity are:
(9) Australia (10) India
Gujarat has been a leader in solar power generation and contributes 2/3rd of the 900 MW of photovoltaics in the country. The State has commissioned Asia’s biggest solar park at Charanka village, District Patan. The park is already generating 214 MW solar power out of its total planned capacity of 500 MW. Rajasthan and Maharastra are the other leading states generating solar energy.
•.2. Wind Energy: is the energy produced through wind. Wind is air in motion. It is caused by the uneven heating of the earth’s surface by the sun. Wind energy is mainly used to generate electricity. Wind is a renewable source of energy.
Wind energy is harnessed through wind mill. A windmill is a machine that collect the wind kinetic energy and converts the energy into rotational energy by means of vanes called sails. Originally, windmills were developed for milling grain for food production. An important use of it is to pump water, either for land drainage or to extract groundwater.
The operation speed of wind to produce power is 4-5 m/s, maximum power can be obtained when speed of wind is 15 m/s whereas at a speed of 25 m/s the wind farm has to shut down to reduce damage to wind mills.
A wind farm is a group of wind turbines in the same location used to produce electric power. Large wind farms consist of hundreds of individual wind turbines which are connected to the electric power transmission network. A large wind farm may consist of several hundred individual wind turbines, and cover an extended area of hundreds of square miles, but the land between the turbines may be used for agricultural or other purposes. A wind farm may also be located offshore. As of 2013, Denmark is generating
more than a quarter of its electricity from wind. Top 10 wind power countries in the world are (according to Global Wind Energy Council): Top states of India Producing wind energy are
Advantages of Wind Energy
•.4. Geothermal Energy - The word geothermal comes from the greek words geo (earth) and therme (heat). Geothermal energy is heat from within the earth. The steam and hot water produced inside the earth can be used to heat buildings or generate electricity. Geothermal energy is a renewable energy source because the water is replenished by rainfall and the heat is continuously produced inside the earth. Temperature hotter than the sun’s surface are continuously produced inside the earth by the slow decay of radioactive particles. Most geothermal reservoirs are deep underground with no visible clues showing above ground. Geothermal energy can be on the surface in the form of volcanoes, hot springs, geysers. Naturally occurring large areas of hydrothermal resources (resources where ground water trapped in porous rock is heated up by magma) are called geothermal reservoirs. Current worldwide installed capacity is 10,715 megawatts (MW), with the largest capacity in the United States (3,086 MW), Philippines, and Indonesia. Uses of Geothermal Energy iv.1. Direct use - hot springs are used for bathing, cooking and heating. iv.2. Geothermal Power Plants - use hydrothermal resources which have two common ingredients water and heat. They require high temperature (300-700 degree Fahrenheit) These resources can be used by drilling wells into the earth and piping the steam or hot water to the surface.
Advantages
Forests are central to all human life because they provide a diverse range of resources: they store carbon, aid in regulating the planetary climate, purify water and mitigate natural hazards such as floods. Forests also contain roughly 90 percent of the world's terrestrial biodiversity.
India is one of the 12 mega biodiverse regions of the world. Total forest cover of India as by Forest Survey of India 2015 report is 21.34%.
Indian forests types include tropical evergreens, tropical deciduous, swamps, mangroves, sub-tropical, montane, scrub, sub-alpine and alpine forests. These forests support a variety of ecosystems with diverse flora and fauna.
There are three major types of forests according to latitude:
1. Tropical- They are characterised by the greatest diversity of species. They occur near the equator, within the area bounded by latitudes 23.5 oN to 23.5 o^ S. - Only two seasons are present i.e. rainy and dry. The length of daylight is 12 hours and varies little. - The average temperature is 20-25oC and varies little throughout the year.
which they take in carbon dioxide and produce oxygen. •.v. Protective functions- forests protect our waters and manage our climate. When it rains in the forests, the leaves allow the water to slowly drip to the ground. Without trees the rain pours hard on the unprotected soil. The dirt washes into streams, muddying the water. This is unhealthy for the fish and can cause flooding and soil erosion. Also without trees the moisture in the air evaporates quickly, changing the climate of nearby forests. Plant cover, root systems, and the quality of topsoil enable good infiltration and water retention. Forests also play a role as landscape and recreation areas. •.vi. Regulative Functions- forest regulates temperature, humidity, precipitation, shape soil environment and different hydrological cycles.
Deforestation- is the permanent destruction of indigenous forests and woodlands. It is the complete cleaning of tree formation and their replacement by using land for other purpose. According to Forest Survey of India Report (2011), forest cover of India is 21.05%.
Factors causing deforestation
3.1. Natural- forest fire, soil erosion, drought
3.2. Economical- agriculture (growing food needs), establishment of heavy industries, development projects, urbanization (population growth), mining, quarrying, agribusiness (growing oil palm, rubber, fruit trees, ornamental plants) 3.3. Traditional- shifting cultivation, grazing, fuelwood gathering
Effects of Deforestation
3.1.Soil erosion 3.2.Expansions of deserts 3.3.Decrease in rainfall 3.4.Loss of fertile land 3.5.Effect of climate 3.6.Lowering of water table 3.7.Loss of flora and fauna 3.8.Environmental changes 3.9.Lack of fuelwood for tribal people Timber Extraction- unlimited exploitation of timber for commercial use leading to decimation of forests. The major effects of timber extraction on forests and tribal people include:
recycled in the environment through hydrological cycle (water cycle). Due to human activities like industrialization, urbanization the surface water as well as ground water is depleting. Excessive use of fertilizers (Nitrogen, Phosphorous) is causing eutrophication.
Eutrophication
When aquatic plant growth is stimulated to produce excessive choking growth eutrophication occurs. The process involves a complex series of inter-related changes in the chemical and biological status of a water body mostly due to a depletion of the oxygen content caused by decay of organic matter resulting from a high level of primary productivity and typically caused by enhanced nutrient input. Sewage is an important source of organic materials in water bodies. Fertilizers and detergents containing Nitrogen and Phosphorous are also the major sources of nutrients. These nutrients greatly increase the productivity in aquatic environments and contribute to eutrophication. Algal blooms are an indication of eutrophication of a water body. A small part of the algal blooms are consumed by zooplanktons and other aquatic organisms like fishes and most of them stay and decay in the water depleting dissolved oxygen. Toxic gases like Hydrogen sulphide is generated. An unpleasant greenish slimy layer is formed on the surface of the water body. This results in the suffocation and eventually death of aquatic organisms. The water body emits bad odor. The anaerobic conditions (Lack of Oxygen) generate toxins in the algae, which can kill surface organisms like birds and animals. The water body cannot be used as a source of water supply nor used for any other activity like recreational use. Acquifer- is an underground layer of water bearing permeable rock from which ground water is extracted using a water well. It is of two types: Unconfined acquifer - water seeps through the permeable layer (permeable rocks or soil) present above it. Confined acquifer - impermeable layer (impermeable rocks) exist above it; water seeps from farther away where the impermeable layer doesn’t exist. Rainwater Harvesting - is the method of utilizing rainwater for domestic and agricultural use by capturing and storing the rainwater above the ground or recharge the underground for its later use. It is essential because-
Rainwater harvesting has the following objectives
The following methods are adopted for modern and traditional harvesting:
Components of Rainwater harvesting systems have the following 5 basic components:
Land Resources Land is finite and valuable resource on which we depend for our housing, food, fibre and fuel wood. Soil, especially the top soil is considered as renewable resources because it is continuously regenerated but the rate of regeneration is a slow process. It take almost 200-1000 year for the formation of 2.5 cm soil, depending upon
When they strike the surface again they either rebound back into the air or knock other particles into the air.
Water logging and induced salinity: Mainly occurs due to faulty irrigation practice, where farmers applied more irrigation water than actually needed for the crop growth. However due to inadequate drainage water get accumulated and form a continuous column with water table. These type of soil are call waterlogged soil which affect crop production due to inhibition of exchange of gases. Water logging is most often associated with the salinity because irrigation water contain salts which get accumulated on soil during evaporation process. Desertification: Desertification is a process whereby the productive potential of arid and semi-arid lands falls by 10% or more. It can be categories as moderate(10-25%), severe ( 25-50%) and very severe( > 50%) drop in productivity. It leads to the conversion of rangelands or irrigated crop land to desert like condition in which agricultural production fall. It is characterized by devegetation, depletion of ground water, salinization and severe soil erosion.
Causes of Desertification: It can be natural due to change in the climate of any area or due to excess exploitation of land to human pressure. The major anthropogenic activities responsible for desertification are as follows:
Conservation of natural resources: Role of an Individual Natural resources like forest, water, soil, food, mineral, energy and land plays a key role in the development of a nation. However these resources are facing risk of depletion due to increased exploitation for human need and required to conserve for future utilization. Conservation efforts are underway at national and international level however individual efforts are also necessary for the resource conservation. Some of the examples of individual conservation efforts are: Water resource:
Environmental problem associated with food resources: Environmental problem associated with food resources are associated with the production of food resources either from agriculture, cattle and poultry breeding and harvesting of fish and other aquatic products. a. Agricultural: Initially agricultural practice were less energy intensive with lower chemical inputs in form of fertilizers and pesticides. However with growing needs of food production agriculture become more energy intensive with more chemical inputs leading to degradation of water and land environment. Main problem associated with the modern agricultural are: