Evaluation of sediment transport in primary tributaries of the Yellow River based on RUSLE and SEDD models: A case study of the Wanchuan River Basin

Abstract

Soil erosion in the Loess Plateau region has been the most serious ecological problem in Northwest China and even North China. A large amount of soil erosion occurs in the mainstream and tributary areas of the Yellow River, which reduces the soil properties of the basin, increases the amount of sand production and siltation in the water flow, and seriously affects the water quality and ecological environment along the shoreline. The Modified Universal Soil Loss Equation (RUSLE) model is widely used worldwide to simulate soil erosion, and its required data are less demanding to obtain. Meanwhile, in order to improve the practicality of the model and facilitate its use in future work, a combination of RUSLE and sediment delivery ratio (SDR) was used to simulate soil erosion in the watershed. Therefore, the Wanchuan River watershed, a first-class tributary of the Yellow River located in Yuzhong County, Lanzhou City, the capital city of Gansu Province, which is located in the Loess Plateau region, with a large difference between the north and south topographies and a high degree of natural erosion, was selected as the study area in this study. By combining different RUSLE model factors, combining measured data and field sampling data, and using the SEDD model to select the most suitable model construction method for the region, the most suitable factor for estimating the average annual soil loss and sediment transport in the Wanchuan River Basin was selected as a combination of the Craw and the R factors generated by the average annual rainfall. It is hoped that the related research will provide feasible suggestions and theoretical references for soil erosion simulation in the main stream and first-level tributaries of the Yellow River.