Water pollution

Water pollution

Drought: In most arid regions of the world the rains are unpredictable. This leads to periods when there is a serious scarcity of water to drink, use in farms, or provide for urban and industrial use. Drought prone areas are thus faced with irregular periods of famine. Agriculturists have no income in these bad years, and as they have no steady income, they have a constant fear of droughts. India has ‘Drought Prone Areas Development Programs’, which are used in such areas to buffer the effects of droughts. Under these schemes, people are given wages in bad years to build roads, minor irrigation works and plantation programs. Drought has been a major problem in our country especially in arid regions. It is an unpredictable climatic condition and occurs due to the failure of one or more monsoons. It varies in frequency in different parts of our country. While it is not feasible to prevent the failure of the monsoon, good environmental management can reduce its ill effects. The scarcity of water during drought years affects homes, agriculture and industry. It also leads to food shortages and malnutrition which especially affects children. Several measures can be taken to minimise the serious impacts of a drought. However this must be done as a preventive measure so that if the monsoons fail its impact on local people’s lives is minimised. In years when the monsoon is adequate, we use up the good supply of water without trying to conserve it and use the water judiciously. Thus during a year when the rains are poor, there is no water even for drinking in the drought area. One of the factors that worsens the effect of drought is deforestation. Once hill slopes are denuded of forest cover the rainwater rushes down the rivers and is lost. Forest cover permits water to be held in the area permitting it to seep into the ground. This charges the underground stores of water in natural aquifers. This can be used in drought years if the stores have been filled during a good monsoon. If water from the underground stores is overused, the water table drops and vegetation suffers. This soil and water management and afforestation are long-term measures that reduce the impact of droughts. Water for Agriculture and Power Generation: India’s increasing demand for water for intensive irrigated agriculture, for generating electricity, and for consumption in urban and industrial centers, has been met by creating large dams. Irrigated areas increased from 40 million ha. in 1900 to 100 million ha. in 1950 and to 271 million ha. by 1998. Dams support 30 to 40% of this area. Although dams ensure a year round supply of water for domestic use, provide extra water for agriculture, industry, hydropower generation, they have several serious environmental problems. They alter river flows, change nature’s flood control mechanisms such as wetlands and flood plains, and destroy the lives of local people and the habitats of wild plant and animal species. Irrigation to support cash crops like sugarcane produces an unequal distribution of water. Large landholders on the canals get the lion’s share of water, while poor, small farmers get less and are seriously affected. Sustainable water management: ‘Save water’ campaigns are essential to make people everywhere aware of the dangers of water scarcity. A number of measures need to be taken for the better management of the world’s water resources. These include measures such as: • Building several small reservoirs instead of few mega projects. • Develop small catchment dams and protect wetlands. • Soil management, micro catchment development and afforestation permits recharging of underground aquifers thus reducing the need for large dams. • Treating and recycling municipal waste water for agricultural use. • Preventing leakages from dams and canals. • Preventing loss in Municipal pipes. • Effective rain water harvesting in urban environments. • Water conservation measures in agriculture such as using drip irrigation. • Pricing water at its real value makes people use it more responsibly and efficiently and reduces water wasting. • In deforested areas where land has been degraded, soil management by bunding along the hill slopes and making ‘nala’ plugs, can help retain moisture and make it possible to re-vegetate degraded areas. Managing a river system is best done by leaving its course as undisturbed as possible. Dams and canals lead to major floods in the monsoon and the drainage of wetlands seriously affects areas that get flooded when there is high rainfall. Dams: Today there are more than 45,000 large dams around the world, which play an important role in communities and economies that harness these water resources for their economic development. Current estimates suggest some 30-40% of irrigated land worldwide relies on dams. Hydropower, another contender for the use of stored water, currently supplies 19% of the world’s total electric power supply and is used in over 150 countries. The world’s two most populous countries – China and India – have built around 57% of the world’s large dams. Dams problems • Fragmentation and physical transformation of rivers. • Serious impacts on riverine ecosystems. • Social consequences of large dams due to displacement of people. • Water logging and salinisation of surrounding lands. • Dislodging animal populations, damaging their habitat and cutting off their migration routes. • Fishing and travel by boat disrupted. • The emission of green house gases from reservoirs due to rotting vegetation and carbon inflows from the catchment is a recently identified impact. Large dams have had serious impacts on the lives, livelihoods, cultures and spiritual existence of indigenous and tribal peoples. They have suffered disproportionately from the negative impacts of dams and often been excluded from sharing the benefits. In India, of the 16 to 18 million people displaced by dams, 40 to 50% were tribal people, who account for only 8% of our nation’s one billion people. Conflicts over dams have heightened in the last two decades because of their social and environmental impacts and failure to achieve targets for sticking to their costs as well as achieving promised benefits. Recent examples show how failure to provide a transparent process that includes effective participation of local people has prevented affected people from playing an active role in debating the pros and cons of the project and its alternatives. The loss of traditional, local controls over equitable distribution remains a major source of conflict. c) Mineral Resources A mineral is a naturally occurring substance of definite chemical composition and identifiable physical properties. An ore is a mineral or combination of minerals from which a useful substance, such as a metal, can be extracted and used to manufacture a useful product. Minerals are formed over a period of millions of years in the earth’s crust. Iron, aluminum, zinc, manganese and copper are important raw materials for industrial use. Important non-metal resources include coal, salt, clay, cement and silica. Stone used for building material, such as granite, marble, limestone, constitute another category of minerals. Minerals with special properties that humans value for their aesthetic and ornamental value are gems such as diamonds, emeralds, rubies. The luster of gold, silver and platinum is used for ornaments. Minerals in the form of oil, gas and coal were formed when ancient plants and animals were converted into underground fossil fuels. Minerals and their ores need to be extracted from the earth’s interior so that they can be used. This process is known as mining. Mining operations generally progress through four stages: (1) Prospecting: Searching for minerals. (2) Exploration: Assessing the size, shape, location, and economic value of the deposit (3) Development: Work of preparing access to the deposit so that the minerals can be extracted from it. (4) Exploitation: Extracting the minerals from the mines. In the past, mineral deposits were discovered by prospectors in areas where mineral deposits in the form of veins were exposed on the surface. Today, however, prospecting and exploration is done by teams of geologists, mining engineers, geophysicists, and geochemists who work together to discover new deposits. Modern prospecting methods include the use of sophisticated instruments like GIS to survey and study the geology of the area. The method of mining has to be determined depending on whether the ore or mineral deposit is nearer the surface or deep within the earth. The topography of the region and the physical nature of the ore deposit is studied. Mines are of two types – surface (open cut or strip mines) or deep or shaft mines. Coal, metals and non-metalliferous minerals are all mined differently depending on the above criteria. The method chosen for mining will ultimately depend on how maximum yield may be obtained under existing conditions at a minimum cost, with the least danger to the mining personnel. Most minerals need to be processed before they become usable. Thus ‘technology’ is dependent on both the presence of resources and the energy necessary to make them ‘usable’. Mine safety: Mining is a hazardous occupation, and the safety of mine workers is an important environmental consideration of the industry. Surface mining is less hazardous than underground mining. Metal mining is less hazardous than coal mining. In all underground mines, rock and roof falls, flooding, and inadequate ventilation are the greatest hazards. Large explosions have occured in coal mines, killing many miners. More miners have suffered from disasters due to the use of explosives in metal mines. Mining poses several long-term occupational hazards to the miners. Dust produced during mining operations is injurious to health and causes a lung disease known as black lung, or pneumoconiosis. Fumes generated by incomplete dynamite explosions are extremely poisonous. Methane gas, emanating from coal strata, is hazardous to health although not poisonous in the concentrations usually encountered in mine air. Radiation is a hazard in uranium mines. Environmental problems: Mining operations are considered one of the main sources of environmental degradation. The extraction of all these products from the lithosphere has a variety of side effects. Depletion of available land due to mining, waste from industries, conversion of land to industry and pollution of land, water and air by industrial wastes, are environmental side effects of the use of these non-renewable resources. Public awareness of this CASE STUDY Sariska Tiger Reserve, Rajasthan The Forest Department has leased land for mining in the Sariska Tiger Reserve area by denotifying forest areas.