Effect of soil and water conservation measures on sediment connectivity
in a catchment on the Loess Plateau
Abstract
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.