Deriving a Soil Loss Equation for Sediment Yield Estimation

The Modified Universal Soil Loss Equation (MUSLE) is one of the commonly used empirical soil erosion models for the estimation of the amount of soil loss from the area of a catchment. Different improved versions of the MUSLE are available. However, in the MUSLE and improved versions of the MUSLE, the effect of topography and the relationship between soil erodibility and runoff on soil erosion and sediment transport are not explicitly explained.The MUSLE and other similar soil erosion models had been developed on the basis of regression analysis, and mathematical or physical interpretation. They do not provide a detailed physical explanation of soil erosion and sediment transport. Therefore, deriving a physically based soil loss equation for sediment yield estimation (SLESYE) becomes important to explain the aforementioned problems. To derive the equation, we considered the potential energy of runoff, the kinetic energy of rainfall, work done by runoff volume, and soil shear resistance. Physically speaking, the SLESYE is the most appropriate than the MUSLE and improved ver sions of the MUSLE, and it is also advantageous to the data-scarce area. Moreover, the SLESYE showed the best performance compared with the MUSLE and an improved MUSLE for all four watersheds under our consideration.