Data for Isolation of factors influencing the distribution of intra-annual sediment discharge in heterogeneous karst watersheds

Isolation of factors influencing the distribution of intra-annual sediment discharge in heterogeneous karst watersheds
Due to the interconnected relationships among complex topography, heterogeneous landscape, frequent extreme climate, shallow and discontinuous soil layer and unique lithological conditions in karst area of southwest China, it is still great challenge to decouple the influence of topography, landscape, climate, soil and lithology on intra-annual variability in sediment discharge. To address this issue, the purpose of this study was to investigate the distribution of intra-annual sediment discharge, and to further disentangle effects of driving forces on intra-annual variability in sediment discharge in 40 heterogeneous karst watersheds of southwest China. The intra-annual variation of sediment discharge was expressed by completely regulation coefficient (Cr), Gini coefficient (G) and Lorentz asymmetry coefficient (S). Partial least squares structural equation model (PLS-SEM) was used to decouple the influence of driving forces on intra-annual variability in sediment discharge. Results showed that sediment discharge is not evenly distributed within the year, and the Cr and G are more than 0.7 in most cases. The relative contribution of water discharge, topography, landscape, climate, soil and lithology factors to the variations of Cr, G and S are 53%, 66% and 17%, respectively. Specifically, topography exerted the largest effect on G (path coefficient β = -0.92, P<0.05), while the other factors had no significant effect on intra-annual variability in sediment discharge. PLS-SEM can effectively reveal the driving force and influencing mechanism of the distribution of intra-annual sediment discharge, and provide an important reference for the sustainable development of soil and water resources in karst watersheds.
Soil erosion; completely regulation coefficient; Gini coefficient; Lorenz asymmetry coefficient; Karst ecosystems