River Valley Development in India: A Critical Review of Environmental Impacts

摘要

The paper presents an overview of environmental effects-positive as well as negative-associated with development, exploitation and management of Water Resources Projects in India. The construction of a dam and reservoir for irrigation, hydropower, or for water supply may create number of primary and secondary environmental degradation processes. In the catchment area, on construction of a project, inhabitants usually migrate and resettle in the surrounding catchment area affecting its ecology, through cultivation, grazing of animals, and other human and agricultural activities, resulting in land degradation. In the reservoir area, large areas may be submerged which, sometimes affect existing settlements and these cause rehabilitation and resettlement problems. In the irrigated area, the expansion of irrigation may change the land use drastically some time resulting in adverse effects. On the positive side, the exploitation of water resources for irrigation, hydropower and flood moderation more particularly, in most of the developing countries with teeming population, has played a critical role in food production, providing critical inputs for local industry and generating foreign exchange earnings. Well managed irrigated agriculture, also contibutes to economic growth, provides higher levels of income for farm families, generates employment and is considered a primary engine for rural development in the low income nations. With increasing awareness for preservation of environment, it has been realised, that developing activities should go hand in hand with efforts to maintain ecological and environmental balance. The important facts about the River Valley Projects and their related environmental impacts have been highlighted in the paper through discussion of the causes, status and remedial measures of the possible adverse impacts of river valley projects. The main complexities in enviornmental impact assessment have been outlined and useful suggestions in this regard are offered for the policy planners of WRD projects.