Numerical calculation of sediment transport capacity of land flow on slopes: method investigation and improvement

To determine the response between the onshore sediment transport capacity (Tc) and various hydraulic parameters, a variable-slope, fixed-bed flume experiment was conducted to investigate Tc for five slopes and six flow rates by comparing five levels of sediment, and a total of 150 experiments were conducted. The results show that among the response relationships between each hydraulic parameter and Tc, the relationships between flow power, unit flow power, and average flow velocity and Tc is significant. In predicting Tc under different soil conditions, the shear stress produced divergence, which should be further explored. The reliability of using slope and flow rate as a single parameter to predict Tc is questionable. As a kinetic index, flow power can be used to predict Tc. The average flow velocity and unit flow power can predict Tc well and are closely related to the soil used in the experiments. The shear stress of water flow can express the evolution of Tc, which is mainly influenced by the median particle size of sediment particles in predicting Tc. The results of the study provide a new method for establishing a prediction model for soil erosion in the loess hilly gully area.