Soil Erosion Estimationin the Bagmati River Basin of Nepal Using RUSLE Modeling to Assess Priority areas for Conservation

Abstract

Abstract Soil erosion is a major issue, resulting in the loss of topsoil and fertility. This study estimates total and average soil loss, analyses the effect of Land Use and Land Cover (LULC) on soil erosion, and prioritizes the soil erosion risk zone in the Bagmati river basin using The Revised Universal Soil Loss Equation (RUSLE) model. Rainfall erosivityfactor (R), Soil erodibility factor, Topographic factor, Cover management factor (C), and Support Practice Factor (P) ranged from 94.25 to 666.11 MJ mm ha− 1 h− 1yr− 1, 0.104 to 0.154, 0 to 24.05, 0 to 0.28, and 0.55 to 1 respectively. The computed annual values of soil loss in the basin ranged from 0 to 201.334 t ha− 1yr− 1in 2010 and 0 to 204.687 t ha− 1yr− 1 in 2016. The average soil loss rate of the basin was 21.5 t ha− 1 yr− 1 in 2016. The average annual soil loss was highest in barren land (10.28 tha− 1) while the minimum was in water bodies (0.69 tha− 1). The maximum erosion potential was found in the agricultural land (204.69 tha− 1). Application of bioengineering techniques can control soil losses in the Bagmati river basin. Overall, the application of modern methods and technology i.e., RUSLE and GIS will be useful for the prediction of potential soil losses from river basins thus, managers and policymakers can implement adequate conservation programs with high erosion risk that will reduce soil loss in the future.