USLE-based models: perspectives and limitations in soil erosion modelling

Water soil erosion is a process of detachment and transport of soil particles due to rainfall and runoff and causes the landform modeling on earthʹs surface. The acceleration of soil erosion process through anthropogenic perturbation has severe impacts on soil which becomes qualitatively poor for crop establishment and growth. Planning soil conservation strategies requires prediction technologies of soil loss over a long‐time period. The Universal Soil Loss Equation (USLE), and its revised versions, are widely tested and applied in different environments throughout the world. At present, the USLE continues to be the most applied model for estimating soil loss and still represents the best compromise between applicability in terms of required input data and reliability of the obtainable soil loss estimates. Recent studies proposed to modify the climatic factor of USLE to give explicit consideration of runoff since this choice is expected to improve both interpretation of soil erosion processes and soil loss predictions. In this paper modified versions of the Universal Soil Loss Equation, which recognize that runoff is a primary independent factor in modeling rainfall erosion and use a general definition of the rainfall‐runoff erosivity factor including the power of both event runoff coefficient QR and event rainfall erosivity index EI30 of the USLE, were reviewed. The parameterization of the USLE‐MM and the USLE‐MB models useful to estimate the soil loss of given return period was also developed.