Identification of Erosion Prone Areas by Morphometric Analysis Using GIS

Abstract

This study was undertaken to determine the priority watersheds for conservation of natural resources of the Haharo sub catchment in the Damodar catchment of upper Damodar valley area having an area of 565 km2 involving four watersheds in Jharkhand State in eastern India by morphometric analysis using topographical maps on a scale of 1:50,000. To define the morphometric features of the watershed, the topographic information of the study area at 1:50,000 scaled are taken for analysis with the help of GIS tools. The topographical information derived from this map is utilized for calculating parameters and fixing of priority of watershed for suggesting conservation measures. The parameters computed include the morphometric parameters like bifurcation ratio, drainage density, stream frequency, texture ratio, and three basin shape parameters i.e., form factor, circularity ratio, and elongation ratio. A rating was done for each of these parameters according to their value. Average of all these parameter for each watershed is calculated to determine the priority. Among the four watersheds 4/4 was the highest priority area where conservation measure has to be taken first then watershed 4/3. Watershed 4/1 was the medium priority area and watershed 4/2 was the low priority area.