Spatial Distribution and Variation Characteristics of Saturated Hydrologic Conductivity on the Chinese Loess Plateau

Abstract

The Chinese Loess Plateau (CLP) plays a vital role as an ecological barrier in maintaining the hydrological and climatic conditions of the Yellow River Basin, preventing desertification, and preserving biodiversity. Conducting a systematic analysis and assessment of the saturated hydrological conductivity (K_sat) on the Loess Plateau is crucial for modeling and simulating processes like surface runoff and solute migration. However, due to the uncertainty in detecting the saturated hydraulic conductivity, there are very few regional spatial analyses of the saturated hydraulic conductivity of the CLP. The research results show that the Campbell model is more suitable for the CLP than others. Spatially, K_sat gradually decreases from northwest to southeast. The K_sat in the surface layer (0 cm) was significantly larger than that at the lower soil depths, and the K_sat variability of each soil layer was moderate. Moran;s I decreased as the lag distance increased; this indicated a positive spatial correlation between K_sat and the correlation gradually decreasing with distance. The scattered points are mainly located in the first quadrant, so the local spatial auto-correlation characteristics of the K_sat in this area are clustered with high values. The K_sat for different land cover on the CLP increases in the order grassland > forest land > agricultural land and increases with elevation. This study improves our understanding of land resources and ecological environment management in the CLP.