Estimation of Erosion Susceptibility and Sediment Yield in Ephemeral Channel Using RUSLE and SDR Model: Tropical Plateau Fringe Region, India

Abstract

Soil erosion susceptibility and huge sedimentation are the major problems in plateau fringe basin under tropical monsoon climate. Ephemeral channel plays a dominant role in a linkage between erosion and sediment deposition in the plateau fringe basin. The objective of this study is to estimate the spatial distribution of potential mean soil erosion (PMSE) rate and gross volume of sediment yield (SY) along with sediment delivery ratio (SDR) in ephemeral outlets at sub-basin scale in Kangsabati basin, situated under Chota Nagpur plateau, India, using coupling models of Revised Universal Soil Loss Equation (RUSLE) and SDR. The models estimated that there is a maximum PMSE (226 t ha−1 year−1 ) occurrence in upper basin along with high mean SY (32 t ha−1 year−1), whereas lower basin has PMSE (74 t ha−1 year−1) with low SY deposition (13.23 t ha−1 year−1). According to sub-basin scale, most of the SY correspondence with PMSE occurs in Khatra-1 (10.22 t ha−1 year−1) and Lalgarh-4 sub-basin (7.2 t ha−1 year−1) out of 27 sub-basins. The result indicates that PMSE is positively significantly correlated with SY (R2 = 0.975) following RUSLE parameters like rainfall erosivity, soil erodibility, slope factor, land cover management, and conservation practice, whereas the role of SDR on SY is determined by basin area and travel time. In spite of model parameters, first stream number (R2 = 0.895) and basin length (R2 = 0.88) positively signify on SY through enhancing the erosion parameters. Gradient ratio positively signifies on SDR (R2 = 0.674) and also determines the role of SDR on SY which controlled the travel time and basin parameter. Therefore, several geo-environmental parameters govern the sediment deposition in plateau fringe basin.