Application of USLE in a GIS environment to estimate soil erosion in the Irga watershed, Jharkhand, India

A comprehensive methodology that integrates the Universal Soil Loss Equation (USLE) and Geographic Information System (GIS) was adopted in this study to determine the soil erosion and sediment yield of the Irga watershed in Jharkhand, India. Based on the availability and applicability of data in a GIS-environment, the original equations for the model input parameters were, however, modified by researchers. In the present study, a power-law equation was generated to estimate the rainfall erosivity (R) factor, and the Nash-Sutcliffe model efficiency coefficient used to determine the accuracy of the modified R factor. Average annual soil erosion in the Irga watershed is estimated to be 4.3 t ha(-1) yr(-1). On the other hand, average annual sediment yield of the watershed, estimated using the sediment delivery ratio, was found to be 1.2 t ha(-1) yr(-1). Low sediment yield indicates that most of the eroded soil was deposited within the watershed.