103. Environmental Issues. 4

Environment protection owes a lot to grass roots movements in the country. A few may be mentioned :  the Chipko Andolan movement led by the veteran Sunderlal Bahuguna in the Tehri Garhwal regions is the oldest. It was followed by the Appiko (embrace the tree when the contractor comes to fell it down) in The Western Ghats region of Karnataka, the Silent Valley Agitation, the protest against dams at Bedthi, and the work of the Kerala Sastra SHitya Parishad  and by many other groups. Then there was the Mitti Bachao Abhiyan to organize the farmers against water logging caused  by faulty irrigation systems. Do you know any other such grass roots movements? Can you analyze the impact of the large dams on ecology? Think about it.(1)

It is a good sign of the times that the man in the street is thinking about the environment. Much remains to be done in regard to pollution levels in the cities. Can you list some of the factors increasing pollution in the cities? Can you suggest the way out? Do you know any other such grass roots movements?(2)


Study the material in the site and make notes. Expect questions both at the Prelims and the Mains.

Smt Indira Gandhi once remarked that poverty is the greatest polluter. At the Stockholm convention, the Brazilian delegate thundered ‘smoke is a sign of progress’ What were they trying to convey? (3)   Do you think that Developing countries have to pay more attention to economic development and too much concern for the environment affects development? Critics speak of environmental fundamentalism.  What do they mean? (4)

Even recreation of nature like afforestation benefits only the rich. Have you any proofs of this? Environmental degradation affects women most? How?(5)

The cities are the curse; the villages are the victims. Do you agree? (6)

More in my next blog.

Prof. Rao

3 thoughts on “103. Environmental Issues. 4

  1. (1) In addition to above mentioned movements, few other movements which are notable: Jungle Bachao Andolan in Bihar (spread to Jharkhand, Orissa in later stages), 1980; Navadanya Foundation by Vandana Shiva in 1982; Tarun Bharat Sangh by Rajinder Singh in Rajashtan, 1985; Target on Soft Drinks (Pepsi, Coca Cola etc.) by Sunit Narain (Director, Centre for Science and Environment), 2003; The Research and Energy Institute by R.K. Pachuri and so on.
    Dams / Reservoirs can be used for Hydro electric power, drinking water etc. However, causes adverse environmental and sociological impacts. The dams floods the natural habitats, contribute to green house gas emissions, leads to downstream erosion etc.
    (2) One of the main causes of urban pollution is the increasing number of vehicles, Factories (so called industrial development). There are no. of ways limiting the number of emissions of vehicles. Encouraging public transport, Colored number plate system used in Mexico, encouraging cycling and taking additional steps for encouraging (like in Glasgow). Solution for factories could be using renewable fuels for running factories, prevent pollutants from being released into urban water supplies.

  2. Impact of large dams on ecology:
    Man has been building dams since the beginning of the historical era. The ancient civilisations of Sumeria, Babylonia, Egypt, Ceylon, Cambodia were all justifiably famed for their irrigation works. The modern advances in concrete technology and the development of vast earth moving machineries has enabled man to build dams of such size and complexity that would have undoubtedly staggered the ancients.
    Land and water are ecologically linked in a natural system known as the watershed. The construction of large dams completely change the relationship of water and land, destroying the existing ecosystem balance which, in many cases, has taken thousands of years to create. The two main categories of environmental impacts of dams are those which are inherent to dam construction and those which are due to the specific mode of operation of each dam. The most significant consequence is that they tend to fragment the riverine ecosystem, isolating populations of species living up and downstream of the dam and cutting off migrations and other species movements.
    One of the first problems with dams is land erosion. Dams hold back the sediment load normally found in a river flow, depriving the downstream of the sediment load. In order to make up for the sediments, the downstream water erodes its channels and banks. One of the purposes to build dams is to prevent flooding. However, most of the ecosystems prone to flooding are adapted to it and various animal species depend on the floods for the stages of reproduction and hatching. Because almost all dams reduce normal flooding, they also fragment ecosystems by isolating the river from its floodplain, turning what fish biologists term a ‘floodplain river’ into a ‘reservoir river’. The vast majority of large dams do not include proper bypass system for the aquatic species, interfering with their lifecycles and thereby causing species extinction of fishes and marine mammal populations. Dam reservoirs in tropical areas become breeding grounds for vectors like mosquitoes, snails and flies due to the slow movement of the water. Dams also change the pattern of the flow of a river, both reducing its overall volume and changing its seasonal variations. The nature of the impacts depends on the design, purpose and operation of the dam, among other things. All parts of a river’s ecology can be impacted by changes to its flow. A river’s estuary, where fresh water meets the sea, is a particularly rich ecosystem. Some 80% of the world’s fish catch comes from these habitats, which depend on the volume and timing of nutrients and fresh water. The alteration of the flows reaching estuaries because of dams and diversions is a major cause of the precipitous decline of sea fisheries in the Gulf of Mexico, the Black and Caspian Seas, California’s San Francisco Bay, the Eastern Mediterranean and others. NASA geophysicist Dr. Benjamin Fong Chao has found evidence that large dams cause changes to the earth’s rotation, because of the shift of water weight from oceans to reservoirs. The earth’s rotation has apparently sped up by eight-millionths of a second since the 1950s.
    The creation of dams and reservoirs also requires relocation of potentially large human populations when constructed close to residential areas. The record for the largest population relocated belongs to the Three Gorges dam built in China. It submerged a large area of land, forcing over a million people to relocate.

  3. Impact of Larger Dam on Eco system:

    1. Larger dams tend to fragment the riverine ecosystem, isolating populations of species living up and downstream of the dam and cutting off migrations and other species movements.

    2.Dams fragment ecosystems by isolating the river from its floodplain, turning what fish biologists term a ‘floodplain river’ into a ‘reservoir river’. This fragmentation of river ecosystems results in a massive reduction in the number of species in the watersheds.

    3. Larger dams impacts sediment and nutrient regimes and alter water temperature and chemistry.

    4.Downstream effect of large dams is that variability in water discharge over the year is reduced; high flows are decreased and low flows are increased, These changes directly and indirectly influence a myriad of dynamic factors that affect habitat heterogeneity and successional trajectories and, ultimately the ecological integrity of river ecosystems

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