Effect of LULC changes on surface runoff in Brahmani river basin using Soil and Water Assessment Tool (SWAT)

Abstract

Understanding the rainfall-runoff process is critical for estimating water availability. The study's major goal is to use a hydrological model (Arc SWAT) to calculate an estimate and surface runoff the influence of  LULCC  (Land Use Land Cover Changes) in the Brahmani River Basin from 1983 to 2019. Two distinct loss models were used to simulate runoff: the Green-Ampt model (GA) and the Soil Conservation Services Curve Number  (SCS-CN) model. As input data to the model, different maps such as the elevation map, drainage map, slope map, land cover map/land use, and soil map of the watersheds are created using GIS technologies and remote sensing. At five observing stations in Keonjhar, Swampatana, Rengali, Akhuapada, and Indupur, the runoff was simulated. Due to a decrease in infiltration rate, runoff increased by 6.06 percent during this period. In the SCS-CN and GA approaches, the coefficient of determination (R2) is 0.89 and 0.87and  the Nash-Sutcliffe efficiency (NSE) is 0.86 and 0.85, respectively, when comparing observed and calculated data. In the Brahmani River Basin, the SCS model performed better than the GA model.