USLE is a statistical relationship model that correlates the amount of soil erosion and its impact factors (climate, soil, topography, vegetation and human activities), and it can be modified according to the local conditions of these factors. USLE was first developed by Wischmeier and
Smith (1965) and was applied to assess the amount of annual soil loss caused by water erosion.
Later, Renard et al. (1997) modified the USLE into a Revised Universal Soil Loss Equation (RUSLE) by introducing an improved means of computing other soil erosion factors.