Geoenvironmental impact analysis of G.B. Pant Sagar reservoir (Rihand Reservoir), U.P. and M.P.

A comparison of aerial photointerpreted data around G.B. Pant Sagar (Rihand Reservoir) for pre-dam (1944) and post-dam (1967) periods and satellite imagery of 1988 shows that slope stability of the hills surrounding the reservoir has not been affected adversely as a result of impounding of the reservoir as no landslides are observed in the area in post-dam period. However, significant changes in the landuse of the area surrounding the reservoir are noticed in the post-dam aerial photographs and satellite imagery. Large areas show decrease in vegetation density as a result of deforestation while the areas bordering the reservoir show increase in vegetation density. The area under cultivation has decreased on the western side due to development of a number of coal fields in post-dam period. Improper management of coal ash disposal from a number of thermal power plants located around the reservoir is causing siltation of the reservoir.