Assessment of Reservoir Sedimentation and Identification of Critical Soil Erosion Zone in Kodar Reservoir Watershed of Chhattisgarh State, India

Abstract

Intense rainfall in a shorter span of time causes a huge amount of erosion resulting in rapid deposition of sediment, consequently reducing the capacity of reservoir. Thus, it is necessary to estimate reservoir sedimentation and identify critical zones susceptible to erosion. With the help of RS and GIS technique, reservoir sedimentation and soil erosion have been assessed in Kodar river watershed. LANDSAT-8 imagery is used to calculate the capacity at various elevations of the reservoir. 14.39% of the reservoir capacity has been lost due to sedimentation in the last 36 years when compared to the designed storage. RUSLE model is being applied to estimate erosion. Thematic maps were prepared for various factors and overlaid in GIS resulting in computation of erosion. The estimated average soil erosion is 5.50 tons/hectare/year. To identify the critical zones, watershed is isolated into 11 sub-watersheds out of which 5 are under critical zone which needs best management practices.