Identification and attribution of severe water erosion regions in China

As a mountainous and agriculturally driven country, China is among the most affected by water erosion globally. However, the spatial patterns and temporal dynamics of severe water erosion regions remain unclear, posing challenges for national soil and water conservation (SWC) efforts. Here, we estimated water erosion in China (2000-2020) based on the Chinese Soil Loss Equation (CSLE) and identified regions with severe water erosion and their main drivers. Results showed the center of gravity of erosion area migrated significantly southwestward during this period. Based on erosion intensity, we reclassified China into four severe and two slight water erosion subregions. The severe water erosion regions are primarily concentrated along the Hu Line. This pronounced geographic pattern results from the combined influence of natural and human factors that promote erosion processes, where steep terrain, intensive agricultural activity, relatively concentrated rainfall, and high soil erodibility interact to enhance water erosion in these regions. Effective mitigation requires optimizing land use by adjusting cropping systems, implementing terraces, and afforestation to reduce erosion and enhance sustainable land management.