Sediment connectivity in different karst watersheds

As a key parameter reflecting the hydrological and soil erosion processes, sediment connectivity is influenced by climate, lithology, soil, topography, and landscape. However, there are few studies on decoupling these factors on sediment connectivity. Therefore, the objective this study was to quantify the relative importance of driving factors on sediment connectivity by partial least squares-structural equation model in 40 karst watersheds. Results showed that the connectivity index (IC) ranged from -0.46 to 1.73 for different watersheds. The 92% of the IC variation can be explained by climate, lithology, soil, topography and landscape. Topographic have the most significant positive influence on IC (P < 0.01, path coefficient (β) = 0.708), while landscape had a significant negative effect on IC (P < 0.05, β= -0.249). By clarifying the coupling relationship framework among the variables, the results provide valuable information for formulating soil and water conservation strategies in karst watersheds.