Question

Why do people oppose the construction of Tehri Dam on the river Ganga and Sardar sarover project on the river Narmada. (Or) Mention three disadvantage of producing hydroelectricity by constructing the dams.(Or) List any three ways in which construction of dams for production of electricity adversely affects the environment of that place.

Answer 1

1. Large area is required to build the dam that result rehabilitation of displaced people. 

2. Large eco-systems are destroyed when submerged under the water in dams. 

3. The vegetation which is submerged rots under anaerobic conditions and gives rise to large amounts of methane gas which leads to a green-house effect.