Characteristics of sediment particle size distribution in the Pisha sandstone area of the middle Yellow River under the effects of vegetation and complex erosion

Pisha sandstone is a soft bedrock composed of sandstone, sand shale and mudstone, with very low diagenesis and erosion resistance. The sources of coarse sediment and the processes of sediment production and transportation in Pisha sandstone areas are currently little understood. Understanding these processes will help us to comprehend the characteristics of sediment particle size distribution on slopes and gullies under the effects of vegetation and complex erosion. This will provide a scientific basis for the control of coarse sediments of the Yellow River and ecological restoration of the Pisha sandstone area. In this study, the process of sediment selectivity and transportation in the slope-gully system was analyzed through soil sampling in different seasons in the Erlaohugou small watershed, China. There is a clear selectivity phenomenon in the process of transporting sediment particles from the slope to the gully, and the coarse sediment particles are transported preferentially from the slope to the gully. There is a good response relationship between the distribution characteristics of sediment particles and the multi-dynamic interaction. The complex erosion type in different seasons has a significant impact on sediment production and transportation, and most particles were transported under hydraulic power.