Dynamic evolution of rainfall erosivity in different rocky desertification areas and analysis of multidimensional driving factors

Karst rocky desertification areas in southwest China, covering eight control zones. This study uses Mann-Kendall test, Gravity Center model, and Optimal Parameter-based Geographical Detectors to analyze spatiotemporal distribution and driving factors of rainfall erosivity (R) in different rocky desertification control zones from 1961 to 2020. It also employs NEX-GDDP-CMIP6 model to predict future changes in R. The results indicate that: (1) The long-term average R in region is 4656.20 MJ mm·ha⁻¹ ·h⁻¹ ·a⁻¹ , with significant variations across different control zones. The maximum and minimum R values are found in Karst Peak Forest-Plain (PFP) and Karst Canyon (KC) zones, respectively. Seasonally, summer has the highest erosivity, followed by spring, autumn, and winter, with increasing trends in summer, autumn, and winter. (2) Rainfall is the primary driver of erosivity, with an average explanatory power exceeding 55 %. The interaction between socioeconomic factors and rainfall significantly contributes to explaining rainfall erosivity. (3) Future predictions show that rainfall erosivity will further increase, with changes ranging from −5.78–85.60 %. Notable increases are observed in Karst Hills and Depression (KHD), Karst Trough Valley (KTV), and PFP zones. The center of erosivity is expected to shift northwest, southwest, and southeast. These findings enhance our understanding of rainfall erosivity in rocky desertification areas and inform the update of soil and water conservation measures. • First study of nature-society interaction on rainfall erosivity in eight rocky zones. • Rainfall erosivity ranking for eight zones: PFP>PCD>KHD>KP>KTV>MHM>KFB>KC. • Future changes in rainfall erosivity for eight zones are from −5.78–85.60 %. • The center of now and later rainfall erosivity is at KTV and non-rocky area boundary.