Drainage Density and Its Application in Soil Erosion Assessment in Sarbari Khad Watershed of Himachal Pradesh, India

Abstract Precise measurement of geomorphometric parameters is significant for assessing watershed conditions, nevertheless these are very difficult to measure accurately in context of the mountain ecosystems and the extensive areas. In the present research work drainage density has been used to assess the soil erosion by employing the Geographical Information System (GIS) for the Sarbari Khad watershed located in the lesser Himalayan region of the Himachal Pradesh, India. For assessing drainage density along with remotely sensed digital data, direct survey based large scale (1:50,000) topographical map have been used. The drainage density analysis unveiled that the Sarbari Khad watershed is vulnerable to surface erosion as well as soil degradation. Further, depending on the drainage density values the watershed has been classified under low, moderate, severe and very severe erosion categories. This classification revealed that about 60 percent area of the watershed suffers from very severe erosion. In this study, the drainage density values have been used for estimating erosion status of watershed. These soil erosion differentials in the watershed can be used for watershed areas prioritization for ensuring soil and water conservation measures to make the watershed sustainable.