Driving forces and their interactions of soil erosion in soil and water conservation regionalization at the county scale with a high cultivation rate

Soil erosion control based on county scale Soil and Water Conservation Regionalization (SWCR) is an essential component of China's ecological civilization construction. In SWCR, the quantitative analysis of the spatial heterogeneity and driving factors of soil erosion among different regions is still lacking. It is of great significance for soil erosion control to deeply examine the factors contributing to soil erosion (natural, land use, and socioeconomic factors) and their interaction at the county and regional levels. This study focused on a highly cultivated area, Hechuan District of Chongqing in the Sichuan Basin. The district (with 30 townships) was divided into four soil and water conservation regions (Ⅰ-Ⅳ) using principal component and hierarchical cluster analysis. The driving factors of soil erosion were identified using the geographical detector model. The results showed that ⅰ) the high cultivation rate was a prominent factor of soil erosion, and the sloping farmland accounted for 78.4% of the soil erosion in the study area; ⅱ) land use factors demonstrated the highest explanatory power in soil erosion, and the average interaction of land use factors explained 60.1% of soil erosion in the study area; ⅲ) the interaction between natural factors, socioeconomic factors, and land use factors greatly contributes to regional soil erosion through nonlinear-enhancement of double-factor enhancement. This study highlights the importance of giving special attention to the effects of land use factors on soil erosion at the county scale, particularly in mountainous and hilly areas with extensive sloping farmland and a high cultivation rate.