Modification of rain and run-off erosivity to predict erosion hazard level on The Manguan Sub-watershed’s Upper Slope

Abstract

To protect natural resources and maintain the normal functioning of hydrological processes, the upper slope of the Manguan Sub-watershed should be designated as a conservation area. However, agricultural activities in the upstream have disrupted the watershed’s hydrological function, triggering high rates of erosion, sedimentation, and flooding. The aim of this research was to estimate the level of erosion hazard on Manguan Sub-watershed’s Upper Slope and its conservation directives to mitigate it. This study adopted a land unit approach to flow occurrence land units with the prediction of MUSLE (Modified Universal Soil Loss Equation) by integrating rainfall and run-off erosivity. The direction of land conservation will be evaluated through the perspectives of land rehabilitation and soil conservation. Based on the result, the prediction of erosion hazard levels is classified into four groups: Low, Moderate, High, and Extremely High. The Manguan Sub-Watershed’s Upper Slope has a significantly high level of erosion and necessitates soil conservation improvement measures on approximately 79% of its area.