Jinjin Pan

and 7 more

Sediment connectivity reflects potential linkages between sediment sources and sink areas and identifies priority regions for implementing sediment control measures. However, the impact of soil and water conservation measures on catchment topography and geomorphological development, as well as their potential effects on sediment connectivity, are not yet fully understood. This study aims to quantify the spatial variations in sediment connectivity induced by the combined effects of terraces and check dams in a representative small catchment on the Loess Plateau. We used the landscape evolution model (LAPSUS) to simulate the spatial distribution of erosion and deposition within the watershed and to determine the spatial coupling patterns between erosion and connectivity. The results indicate that: (i) Soil and water conservation measures effectively reduced sediment connectivity within the catchment, with terraces, check dams, and their combined effect contributing to a 19.55%, 4.82%, and 31.99% reduction in sediment connectivity, respectively. (ii) Soil and water conservation measures altered the erosion-deposition spatial distribution patterns within the catchment. Terraces reduced the area of soil erosion on slopes by 33.44%, while check dams increased the area of sediment deposition in channels by 90%. (iii) Low erosion-high connectivity and high erosion-high connectivity zones were key areas for soil erosion and sediment loss within the catchment, located on steep slopes and highly erodible channels. The research findings contribute to the development of more effective soil and water conservation programmable for erosive small catchments in the Loess Plateau, enhancing the sustainability of catchment management.