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Note for Environment Science and Engineering - ESE by Rupesh Kumar Nayak

  • Environment Science and Engineering - ESE
  • Note
  • Biju Patnaik University of Technology Rourkela Odisha - BPUT
  • Computer Science Engineering
  • B.Tech
  • 8 Topics
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3 c. Land bank d. Atmospheric regulation 2) Productive functions a. Fodder for cattle b. Fuel wood and charcoal c. Poles for building homes d. Food: (consumptive use) e. Sericulture & Apiculture f. Medicinal plants for traditional medicines 3) Recreational and educational functions 4) Development functions a. Employment functions b. Revenue Commercial uses  Man depends heavily on a larger number of plant and animal products from forests for his daily needs.  The chief product that forests supply is wood, which is used as fuel, raw material for various industries as pulp, paper, newsprint, board, timber for furniture items, other uses as in packing articles, matches, sports goods etc.  Indian forests also supply minor products like gums, resins, dyes, tannins, fibers, etc.  Many of the plants are utilized in preparing medicines and drugs; Total worth of which is estimated to be more than $300 billion per year.  Many forests lands are used for mining, agriculture, grazing, and recreation and for development of dams. Ecological uses The ecological services provided by our forests may be summed up as follows:  Production of Oxygen: The main green house gas carbon dioxide is absorbed by the forests as a raw material for photo synthesis. Thus forest canopy acts as a sink for carbon dioxide thereby reducing the problem of global warming caused by green house gas CO2  Wild life habitat: Forests are the homes of millions of wild animals and plants. About 7 million species are found in the tropical forests alone.

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4  Regulation of hydrological Cycle: Forested watersheds act like giant sponges, absorbing the rainfall, slowing down the runoff. They control climate through transpiration of water and seed clouding.  Soil Conservation: Forests bind the soil particles tightly in their roots and prevent soil erosion. They also act as wind breakers.  Pollution moderators: Forests can absorb many toxic gases and can help in keeping the air pure and in preventing noise pollution. OVER EXPLOITATION OF FORESTS  Man depends heavily on forests for food, medicine, shelter, wood and fuel.  With growing civilization the demands for raw material like timber, pulp, minerals, fuel wood etc. shot up resulting in large scale logging, mining, road- building and clearing of forests.  Our forests contribute substantially to the national economy.  The international timber trade alone is worth over US $ 40 billion per year.  The devasting effects of deforestation in India include soil, water and wind erosion, estimated to cost over 16,400 cores every year. Ecological Significance of Forests 1) Balances CO2 and O2 levels in atmosphere. 2) Regulates earth temperature and hydrological cycle 3) Encourage seepage and reduces runoff losses, prevents drought 4) Reduces soil erosion (roots binding), prevents siltation and landslides thereby floods 5) Litter helps in maintaining soil fertility 6) Safe habitat for birds, wild animals and organisms against wind, solar radiation and rain. DEFORESTATION Deforestation refers to the loss of forest cover; land that is permanently converted from forest to agricultural land, golf courses, cattle pasture, home, lakes or desert. Causes for Deforestation  Agriculture: Conversion of forests to agricultural land to feed growing numbers of people.  Commercial logging: Destroys

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5  The cash crop economy: Raising cash crops for increased economy.  Mining  Increase in population: The needs also increase and utilize forests resources.  Urbanization & industrialization  Mineral exploration  Construction of dam reservoirs  Infrastructure development  Forest fires  Human encroachment & exploitation  Pollution due to acid rain Environmental effects /Consequences of deforestation  Food problems  Ecological imbalance  Increasing CO2  Floods leading to soil erosion  Destruction of resources  Heavy siltation of dams  Changes in the microclimate  Loss of biodiversity  Desiccations of previously moist forest soil  Environmental pollution  Global warming CONSERVATION Conservation derived from two Latin words, con – together, servare – to keep or guard measures, i.e. an act of preservation or to keep together. Concepts in conservation  Restraining cutting of trees and submerging the forests  Reforestation  Afforestation  Control forest diseases and forest fire  Recycling forest products

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6  Replacing forest products TIMBER EXTRACTION AND MINING The major activities in forest area are 1) Timber extraction 2) Mining The important effects of timber extraction are i) Thinning of forests ii) Loss of biodiversity, particularly tree breading species iii) Soil erosion and loss of soil fertility iv) Migration of tribal people from one place to another in search of new forest v) Extinction of tribal people and their culture Mining is a process of removing ores from area which is very much below the ground level. Mining is done for the extraction of several minerals of metals like Fe, Mn, Au, Ag, etc. The minerals are especially found in thick forests. Mining can be carried out in two ways 1) Surface mining 2) underground mining or sub-surface mining The effects of under ground mining on forest reserves are comparatively less than that of surface mining. DAMS – BENEFITS AND PROBLEMS River valley projects with big dams are considered to play a key role in the development of a country. India has large number of river valley projects. 1. These dams are regarded as symbol of national development. 2. Provides large scale employment of tribal people and increase the std. of living of them 3. Contribute for economic uplift and growth 4. Help in checking flood 5. Generate electricity 6. Reduce power and water shortage 7. Provide irrigation water 8. Provide drinking water to remote areas 9. Promote navigation and fishery.

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