Vegetation cover modelling for soil erosion control in agricultural watershed

Abstract

Abstract Vegetation has an important role in surface runoff and soil erosion control. Deforestation, especially in the upstream watersheds, has increased land degradation problems, mainly in the form of soil erosion. This study aims to investigate the effectiveness of vegetation cover for soil erosion control in an agricultural watershed. Soil erosion calculation was performed using Revised Universal Soil Loss Equation (RUSLE) model. While spatial analysis tools of Arc GIS 10.3 were used for soil erosion-vegetation correlation modelling. Five parameters such as rainfall erosivity (R), soil erodibility (K), length-slope factor (LS), crop management factor (C) and conservation practices factor (P) used to assess soil erosion in the existing condition. Those parameters were presented in grids cell of land units with 30 meters resolution. Five scenarios of vegetation cover such as 10%, 15%, 20%, 25% and 30% were used for the modelling. The result showed the increase of vegetation cover from the existing condition from 4.8% to 30% can significantly reduce about 76% of soil erosion. Preservation of about 30% vegetation cover in the upstream area of the watershed, enables farming practices with a low risk of soil erosion. The findings of this study provide a fundamental base for conservative farming concept development.