LESSON 3.pdf

LESSON 3- NATURAL RESOURCES Many forests lands are used for mining, agriculture, grazing, and recreation and for development of dams. NATURAL RESOURCES -Any component of the environment which has...

LESSON 3- NATURAL RESOURCES Many forests lands are used for mining, agriculture, grazing, and recreation and for development of dams. NATURAL RESOURCES -Any component of the environment which has intrinsic value Ecological Uses of its own is called as resource. Any component which can be The ecological services provided by our forests may be transferred in a way such that it becomes more valuable and summed up as follows: useful is termed as resource. Production of Oxygen: The main greenhouse gas carbon dioxide is absorbed by the forests as a raw material for The main problem associated with natural resources is photosynthesis. Thus forest canopy acts as a sink for carbon unequal consumption. A major part of natural resources are dioxide thereby reducing the problem of global warming consumed in the ‘developed’ world. The ‘developing nations’ caused by greenhouse gas CO2 also over use many resources because of their greater human Wild life habitat: Forests are the homes of millions of wild population. animals and plants. About 7 million species are found in the tropical forests alone. However, the consumption of resources per capita (per Regulation of hydrological Cycle: Forested watersheds act individual) of the developed countries is up to 50 times like giant sponges, absorbing the rainfall, slowing down the greater than in most developing countries. Advanced runoff. They control climate through transpiration of water countries produce over 75% of global industrial waste and and seed clouding. greenhouse gases. Soil Conservation: Forests bind the soil particles tightly in their roots and prevent soil erosion. They also act as wind Energy from fossil fuels consumed in relatively much greater breakers. quantities in developed countries. Their per capita Pollution moderators: Forests can absorb many toxic gases consumption of food too is much greater as well as their and can help in keeping the air pure and in preventing noise waste. The USA for example with just 4% of the world’s pollution. population consumes about 25% of the world’s resources. Over Exploitation of Forests Producing animal food for human consumption requires Man depends heavily on forests for food, medicine, shelter, more land than growing crops. Thus countries that are highly wood and fuel. dependent on non-vegetarian diets need much larger areas With growing civilization, the demands for raw material like for pastureland than those where the people are mainly timber, pulp, minerals, fuel wood etc. shot up resulting in vegetarian. large scale logging, mining, road- building and clearing of forests. FOREST RESOURCES Our forests contribute substantially to the national -A forest can be defined as a biotic community predominant economy. of trees, shrubs or any other woody vegetation usually in a The international timber trade alone is worth over US $ 40 closed canopy. It is derived from latin word ‘foris’ means billion per year. ‘outside’. The devasting effects of deforestation in India include soil, water and wind erosion, estimated to cost over 16,400 cores Forest Functions: every year. 1) Protective and ameliorative functions Ecological Significance of Forests a. Watershed protection 1) Balances CO2 and O2 levels in atmosphere. b. Erosion control 2) Regulates earth temperature and hydrological cycle c. Land bank 3) Encourage seepage and reduces runoff losses, prevents d. Atmospheric regulation drought 4) Reduces soil erosion (roots binding), prevents siltation and 2) Recreational and educational functions landslides thereby floods 5) Litter helps in maintaining soil fertility 3) Development functions 6) Safe habitat for birds, wild animals and organisms against a. Employment functions wind, solar radiation and rain b. Revenue DEFORESTATION 4) Productive functions - refers to the loss of forest cover; land that is permanently a. Fodder for cattle converted from forest to agricultural land, golf courses, cattle b. Fuel wood and charcoal pasture, home, lakes or desert. The FAO (Food and c. Poles for building homes Agriculture Organization of the UN) defines tropical d. Food: (consumptive use) deforestation as“ change of forest with depletion of e. Sericulture & Apiculture tree crown cover more than 90%” depletion of forest tree f. Medicinal plants for traditional medicines crown cover less than 90% is considered forest degradation. Commercial Uses Causes for Deforestation Man depends heavily on a larger number of plant and Agriculture: Conversion of forests to agricultural land to animal products from forests for his daily needs. feed growing numbers of people The chief product that forests supply is wood, which is used Commercial logging: Destroys as fuel, raw material for various industries as pulp, paper, The cash crop economy: Raising cash crops for increased newsprint, board, timber for furniture items, other uses as in economy. packing articles, matches, sports goods etc. Mining Many of the plants are utilized in preparing medicines and Urbanization & industrialization drugs; Total worth of which is estimated to be more than Increase in population: The needs also increase and utilize $300 billion per year. forests resources.  Mineral exploration Construction of dam reservoirs Clean water is universal right. It is the responsibility of Infrastructure development everyone to ensure the purity of water. Water is a valuable Forest fires commodity and it has to be conserved. Human encroachment & exploitation Pollution due to acid rain Surface water: When evaporation and transpiration rates are lower than the rainfall, surface water body like lake, Environmental effects /Consequences of deforestation river,pond, streams etc. are formed. Floods leading to soil erosion Flood: over flow of water, whenever the water in flow is Destruction of resources greater than the carrying capacity of the channels flood Heavy siltation of dams occurs. Changes in the microclimate Desiccations of previously moist forest soil Causes: Global warming Heavy rainfall, snow melt, sudden release of water from Loss of biodiversity dams. Food problems Prolonged down pour leading to overflowing of rivers and Ecological imbalance lakes Increasing CO2 Reduction in carrying capacity due to obstructions or Environmental pollution sediments etc. Deforestation, overgrazing, mining increases water run off CONSERVATION Removal of dense forests from hilly regions -derived from two Latin words, con – together, servare – to keep or guard measures, i.e. an act of Effects: preservation or to keep together. Submerges the flooded area Loss of soil fertility due to soil erosion Concepts in conservation Extinction of civilization at coastal area Restraining cutting of trees and submerging the forests Reforestation Drought Afforestation -Unpredictable delay in climatic condition occurring due to Control forest diseases and forest fire monsoon rain failure. Recycling forest products Types: Replacing forest products Meteorological: in order of month or year, actual moisture supply at a given place consistently falls below critical level. WATER RESOURCES Hydrological: iciency in surface and subsurface water -an indispensable resource. Around 97% of world surface is supplies covered with water. Most of the animals and plants have 60- Agricultural: inadequate soil moisture to meet the need of 65% of water in their body. a particular crop at particular time or susceptibility of crops during different stages in its development Unique features of water: Socioeconomic: reduction in the availability of food and High specific heat social securing of people High latent heat of vaporization Good solvent for oxygen, nutrients and pollutants Causes: Anomalous expansion on freezing Deforestation and lesser rainfalls coupled with cutting of High surface tension trees for timber leads to desertification. Over drafting of ground water, subsidence of soil, drying of Global distribution of water is very much random depending wetlands on the geographical conditions. The availability of water Pollution of soil with solid waste, industrial effluents etc. decreases in the following order. makes land useless and dry Tropical rain forest Population explosion in man and livestock leads to Temperate regions enhanced requirement of timber, fuel wood, grazing Deserts Shifting cultivation Water is used for domestic, irrigation and also industrial Effects: purposes. Out of the total available water 75% is used for Increase of water in stream pond agriculture, 20% for industrial usage. Ground water table get declined Loss of agricultural crops Ground water: 9.86% of fresh water is ground water and it is Loss of biodiversity 35-50% greater than surface water. Government spent a lot of money as drought relief fund Aquifer: The layer of soil which is permeable has the ability to store water is called an aquifer. It is generally made up of Control Measures: gravel, sand etc. Rain water harvesting Unconfined aquifer: it is covered by permeable layer. The Watershed management recharge of this layer is by rainfall or snowmelt. Prevent deforestation Confined aquifer: sandwiched between impermeable layers. Encourage afforestation The recharge is through unconfined aquifer layers. CONFLICTS OVER WATER Over Utilization of Ground Water -Due to increase in population and decrease in -Over utilization of water leads to rapid depletion of water waternresources conflicts over water starts Conflicts over the resources, ground subsidence, lowering of water table and water around world was classified as water logging. Control of water resources  Military food resources Medical system- particularly in Ayurvedic System Political resources Formation of alloys for various purposes Terrorism Agriculture- as fertilizers, seed dressings and fungicides Military targets Jewelry- e.g. Gold, silver, platinum, diamond Development disputes Environmental impacts of mineral extraction Causes: Environmental impacts of over extraction of mineral Conflicts through use: resources: 1. Shipping traffic in international water 2. Dam construction Depending on the conditions of the terrain and depth of 3. Construction of power stations deposits, 2 types of mining operations are carried out. 4. Conflicts through pollution-rhine river, Europe 1. Open cast mining 5. Distributional conflict-relative storage 2. Underground mining In both types, each steps in mining processing produce Conflicts management: several environmental effects such as, Enact laws to check practices to control water pollution Sharing river solved by interlinking river Great volume of debris has been generated which disrupt Power must be given to national water authority the surface and ground water circulation. It also reduces the water carrying capacity of streams very close to mining area. DAMS –BENEFITS AND PROBLEMS The stacking of over burden and building of soil banks -Dams are built across the river in order to store water for creates problems of landslides. drinking, agricultural, industrial purpose. Now days they are Mining and ore processing normally causes air pollution mainly used for the hydropower production. and water pollution. The acid water generated in coalmines can pose a serious Benefits problem of water pollution, which adversely affects the flora River valley projects with big dams play a key role in the and fauna. development process due to their multiple uses. Deeper excavation of ground causes lowering of water These dams aim at providing employment for tribal people table, which leads to drying of wells or sea water intrusion. and raising the standard and quality of life. Deforestation takes place due to removal of vegetal covers. -Dams can help in checking floods and generate electricity Underground fire in coalmines is a hazard that is difficult to and reduce water and power shortage, provide irrigation control. water to lower areas, provide drinking water in remote areas In stone quarries, blasting of rocks not only annoying the and promote navigation, fishery. people nearby, but also cause hazard from fly rocks and dusts and damage to buildings due to vibrations. Problems The disposal of waste material produced after The impacts of big dams can be upstream as well as concentrations of ore create increase concentration of heavy downstream levels. The upstream problems include the metals and toxic elements in the environment. following: Displacement of tribal people Impacts of mining: Loss of forests, flora and fauna Mining is done to extract minerals from deep deposits in soil. Changes in fisheries Environmental damages caused by mining activities are as Saltation and sedimentation of reservoirs follows: Loss of non-forest land Stagnation and water logging near reservoir Devegetation and defacing of lands: Mining requires removal Breeding vectors and spread of vector –borne diseases of vegetation along with underlying soil mantle and overlying Reservoir induces seismicity causing earthquakes rock masses. This results in destruction of landscape in the Microclimatic changes area. Growth of aquatic weeds Subsidence of land: Subsidence of mining areas results in Downstream problems include the following: tilting of buildings, cracks in houses, buckling of roads, Water logging and salinity due to over irrigation bending of rail tracks and leaking of gas from cracked pipe Microclimatic changes lines leading to serious disasters. Reduced water flow and slit deposition in river Flash foods Groundwater contamination: Mining pollutes the Salt water intrusion at river mouth groundwater. Sulphur, usually present as an impurity in many Loss of land fertility ores is known to get converted into sulphuric acid through Outbreak of vector-borne diseases like malaria. microbial action, thereby making the water acidic. MINERALS RESOURCES Occupational Health Hazards: Miners working in different -Minerals are naturally occurring substances with definite type of mines suffer from asbestosis, silicosis, black lung chemical and physical properties. Mineral is an element or disease. inorganic compound that occurs naturally Surface water pollution: The acid mine drainage often Uses of minerals contaminates the nearby streams and lakes. The acidic water, Development of industrial plants and machinery radioactive substances like uranium, heavy metals also Generation of energy e.g. coal, lignite, uranium contaminate the water bodies and kill aquatic animals. Construction, housing, settlements Defense equipments- weapons, settlement Air pollution: In order to separate and purify the metal from Transportation other impurities in the ore, smelting is done which emits Communication-telephone wires, cables, electronic devices enormous quantities of air pollutants. Oxides of sulphur, arsenic, cadmium and lead etc. shoot up in the atmosphere Monoculture is the same genotype is grown over vast areas. near the smelters and the public suffers from several health Disease spread easily problems. Micronutrient imbalance e.g. Zinc deficiency-affect soil productivity Remedial measures Nitrate pollution-nitrogenous fertilizers applied deep soil Adopting eco-friendly mining technology contaminates ground water. cause blue baby syndrome Utilization of low grade ores by using microbial – leaching methaemoglobinemia- affects infants technique. In this method, the ores are inoculated with the Eutrophication: Over nourishment of lakes due to desired strains of bacteria like Thiobacillus ferroxidans, which agriculture remove the impurities and leave the pure mineral. field wash out-leads to algal bloom-dead organic matters Re-vegetating mined areas with appropriate plants increases due to decomposition-leads to oxygen demand Gradual restoration of flora Prevention of toxic drainage discharge Problems associated with pesticide use: Evolution of genetic resistance FOOD RESOURCES Imbalance in ecosystem Overgrazing: Creation of new pest Land degradation Persistence, Bioaccumulation and Biomagnification Soil erosion Mobility through soil, water, air, washed away into rivers, Loss of useful species streams, when it rains can harm fishes Problems Faced by Food Resources Creating super pest Modern agriculture: Death of non-target organisms High yield variety crops Salinity Micronutrients imbalance Water logging Nitrate pollution Eutrophication Water logging / salinization: Pesticide related problems Saturation of soil with irrigation water or excessive Water logging precipitation. So that water table rises close to surface. Salinity Water logging results when soils are over irrigated without World Food Problems drainage. Occurs in clayey soil, soil root zone becomes Problems mainly under nutrition and malnutrition saturated with so much water blocking oxygen supply for Natural calamities: famine, drought, earthquake, flood, gale, growth and soil becomes unsuitable. storm Disease and medical facilities Carbon dioxide and ethylene accumulate around roots affect Pest damage: insects, bacteria, viruses, parasites consume the plants. 60% of worlds food production Hunger ENERGY RESOURCES Population explosion in rural areas -Growing energy needs: Population explosion, Luxurious life, Industries, Agriculture, mining, transportation, lighting, World Food Problems cooling, heating, building all need energy. Fossil fuels like coal, Environmental pollution oil, natural gas produce 95% of energy. Lack of water for irrigation Less rainfall due to deforestation SOURCES OF ENGERY Livestock overgrazing Primary: Overfishing Renewable energy – resources which can be generated continuously in nature and are in exhaustible and can be CHANGES CAUSED BY OVERGRAZING AND AGRICULTURE used again endlessly. Wood, Tidal, Solar, wind, hydropower, biomass, biofuel, geothermal, hydrogen Overgrazing: Process of eating away the vegetation along Non-renewable energy – Resources which have with its roots without giving a chance to regenerate accumulated in nature over a long span of time and cannot Land degradation-leads to organically poor, dry, be quickly replenished when exhausted coal, petroleum, compacted soil cannot be used for further cultivation natural gas Soil erosion-cover of vegetation gets removed from soil Secondary: Petrol, electrical energy, coal burning. Loss of useful species-good quality grasses and herbs with high nutritive value, when grazed lose even the root stocks Use of alternate energy sources: which carry the reserve food for regeneration get destroyed -Refers to energy sources which are not based on the burning which gives raise to secondary species like parthenium, of fossil fuels or the splitting of atoms. Lantane, Xanthium etc. To prevent –match the forage supplement to the herds Solar energy: requirement Total energy from sun per year-35,000 times the energy used by man Modern agriculture: The practice through which specific Used to run car, power plants and spaceships plant species are cared and managed so as to obtain maximum yield of consumable parts of plants – agriculture Energy harvesting devises: makes use of hybrid seeds and selected and single crop Solar heat collectors variety, high tech equipment and lots of energy subsides in Solar cells the form of fertilizers, pesticides and irrigation water e.g. Solar cooker green revolution Solar water heater Solar furnace Impacts related to high yielding varieties: Solar power plants  Road building Wind energy: Unscientific quarrying etc. Average wind velocity of earth - 9 m/sec and power produced Engineering Constructions when a windmill is facing the wind is 10 miles/hr-50 watts. eg. largest wind farm-Kanyakumari in tamilnadu is generating Soil erosion: 380 MW electricity. 1. Terracing: Terracing reduces soil erosion on steep slopes by concerting the land into a series of broad, level terraces. Hydro power: This retains water for crops at each level and reduces soil Comes from damming of rivers and utilization of high erosion by water runoff. pressure, its kinetic energy is transformed into turbine blades and used to generate electricity 2. Contour Farming: This method is adopted for gently sloped Minimum water falls height-10 m land. This involves planting crops in rows across the contour of gently sloped land. Tidal Energy: Uses the natural motion of tides to fill reservoirs which are 3. Alley Cropping or Agro forestry: In this method crops are then slowly discharged through electricity producing turbines. planted together in strips or alleys between trees and shrubs that can provide fruits and fuel wood. The trees and shrubs Ocean thermal energy: provide shade which reduce water loss by evaporation and Energy available due to the difference in water temperature. preserve soil moisture. The surface of the tropical ocean and at deeper level is called OTE. A difference of 20 degree celcius or more is required for 4. Wind Breaks or Shelter Belts: Wind breaks and shelter operating OTE power plants. belts or trees are established to reduce wind erosion and also for retaining soil moisture. Geothermal energy: Energy harassed from the hot rocks inside earth. E.g. Natural ROLE OF INDIVIDUAL IN CONSERVATION OF NATURAL geysers in Manikaran RESOURCES Natural resources-forest, water, soil, food, mineral and LAND RESOURCE energy -Land is critically important national resource which supports Overuse of these resources cause problems all living organisms including plants and animals. The soil profile of land determines its ability to serve socioeconomic Protect soil: needs. Don’t uproot plants -It has been estimated that more than 5000 million tons of Grow grass which binds soil and prevent erosion top soil is eroded annually along with 5 million tons of Make compost nutrients. About 1/3 of this is lost in sea while the rest in Use green manure reservoirs and rivers leading to flood. Don’t over irrigate -Effective steps have to be taken for preventing diversion of Use mixed cropping land suitable for sustainable farming to non-farm uses. Simultaneously, degraded lands and waste lands have to be Conserve water: improved by ecological restoration. The Department of Land Don’t keep water taps running Resources was setup in April 1999 by ministry of Rural Install water saving toilets Development to act as nodal agency for land resource Check for water leaks management. Reuse soapy water Use drip and sprinkling irrigation Land Degradation: Conserve energy Land degradation is defined as the reduction in soil capacity Turn off lights, fan when not in use to produce in terms of quality, quantity goods and services. Use solar cooker for cooking The definition is also based on Try riding bicycle 1. Sustainability or ability to produce continuously and indefinitely. 2. Quality of land resource that makes it sustainable or resistant to degradation 3. Carrying capacity or the number of people and animals the land can normally support without significant stress. Landscapes generally undergo degradation but are usually compensated by nature’s inherent recovering ability. Whenever degradation occur exceeding nature’s restorative capacity, the result will be a disaster. Man induced landslides: The hill slopes are prone to landslides, landslips, rockslides etc. These hazardous features have reduced the overall LESSON 4- ENVIRONMENTAL IMPACT ASSESSMENT progress of the region as they obstruct the roads, communication media and water flow. There are two types ENVIRONMENTAL INVENTORIES of slides: -The first step in evaluating the environmental impact of a 1. Slides due to natural factors project’s alternatives is to inventory factors that may be 2. Slides induced by man and his activities affected by the proposed action. Existing conditions are Some of the human activities that cause land sliding are measured and described, but no effort is made to assess the Massive deforestation importance of a variable. Any number and many kinds of Erratic agricultural practices variables may beincluded, such as: 1. the “ologies”: hydrology, geology, climatology, technique because the numerical ranking implies a subjective anthropology, and archaeology; judgment by the environmental assessment team. A checklist 2. environmental quality: land, surface and subsurface water, remains a convenient method for developing a FONSI, air, noise, and transportation impacts; although a FONSI requires subjective selection of the number 3. plant and animal life; judged to be the lowest value of significance. 4. economic impact on the surrounding community: number of jobs, average family income, etc.; USE OF RISK ANALYSIS IN ENVIRONMENTAL ASSESSMENT 5. analysis of the risks to both people and the natural The rationale for including risk analysis in environmental environment from accidents that may occur during the life of impact assessment is threefold: the project; and 1.Risk analysis provides a method for comparing low 6. other relevant socioeconomic parameters, like future land probability, high- consequence impacts with high-probability, use, expansion or diminution of the population of urban lowconsequence impacts. areas and exurbs, the impacts of nonresident populations, 2.Risk analysis allows assessment of future uncertain impacts, and environmental justice considerations. and incorporates uncertainty into the assessment. 3.The United States and international agencies concerned ENVIRONMENTAL ASSESSMENT with regulating environ- mental impact are adopting risk- The process of calculating projected effects that a proposed based standards in place of consequence-based standards. action or construction project will have on environmental quality is called environmental assessment. A methodical, reproducible, and reasonable method is needed to evaluate both the effect of the proposed project and the effects of alternatives that may achieve the same ends but that may have different environmental impacts. A number of semi quantitative approaches, among them the checklist, the interaction matrix, and the checklist with weighted rankings, have been used. Checklists are lists of potential environmental impacts, both primary and secondary. Primary effects occur as a direct result of the proposed project, such as the effect of a dam on aquatic life. Secondary effects occur as an indirect result of the action. For example, an interchange for a highway may not directly affect wildlife, but indirectly it will draw such establishments as service stations and quick food stores, thus changing land use patterns. The checklist for a highway project could be divided into three phases: planning, construction, and operation. During planning, consideration is given to the environmental effects of the highway route and the acquisition and condemnation of property. The construction phase checklist will include displacement of people, noise, soil erosion, air and water pollution, and energy use. Finally, the operation phase will list direct impacts owing to noise, water pollution resulting from runoff, energy use, etc., and indirect impacts owing to regional development, housing, lifestyle, and economic development. The checklist technique thus lists all of the pertinent factors; then the magnitude and importance of the impacts are estimated. Estimated importance of impact may be quantified by establishing an arbitrary scale, such as: 0 = no impact 1 = minimal impact 2 = small impact 3 = moderate impact 4 = significant impact 5 = severe impact The numbers may then be combined, and a quantitative measurement of the severity of the environmental impact for any given alternative be estimated. In the checklist technique most variables must be subjectively valued. Further, it is difficult to predict further conditions such as land-use pattern changes or changes in lifestyle. Even with these drawbacks, however, this method is often used by engineers because of its simplicity. Impact assessments of controversial projects often do not use the checklist