Improvement of land surface vegetation ecology inhibited precipitation-triggered soil erosion in the alpine-cold river source area – A case study in Southern Gansu, China

Study region: Southern Gansu Plateau (SGP), located in the northeastern region of the Qinghai-Tibet Plateau, is a representative alpine-cold water source area for China’s large rivers, such as the Yellow River and Yangtze River. Study focus: Identifying the contributions of dominant factors to the regional soil erosion rate (A) is important for understanding the environmental processes and benefits of water and soil conservation, although related studies have seldom been conducted in alpine-cold regions such as the SGP. Accordingly, the main objectives of this study are (1) to determine the spatiotemporal dynamics of soil erosion and its driving factors in the SGP area; (2) to quantify the relationship between the main influential factors and soil erosion; and (3) to separate the contributions of the above factors to variations in regional soil erosion on the SGP. New hydrological insights for the region: The multiyear average regional A for the SGP region was calculated as 24.18 t·hm−2·a−1, corresponding to an overall low intensity of regional soil erosion. The contributions of various time-varying factors, such as rainfall, vegetation cover, and conservation practices, to the reduction in A were −20.01%, 81.07%, and 21.95%, respectively, indicating that the improvement in land surface vegetation ecology dominated the decrease in A under the background of climate warming. The findings are expected to contribute to soil and water conservation in alpine-cold river source regions.