Extreme rainfall erosivity shapes comprehensive soil erosion risk and exposure patterns in the Qinling-Huaihe region, China

Study region The Qinling-Huaihe region lies within the north-south climatic transition zone of China’s East Asian monsoon region and exhibits pronounced regional differences in precipitation, topography, and socioeconomic conditions. Study focus This study developed a framework of extreme rainfall erosivity analysis-comprehensive soil erosion risk assessment-risk-exposure correspondence analysis. It examines spatiotemporal changes in general extreme rainfall erosivity (R95) and strong extreme rainfall erosivity (R99), comprehensive soil erosion risk patterns and contribution structures, and the concentration and spatial correspondence of socioeconomic exposure across risk levels. New hydrological insights for the region The combined average contributions of R95 and R99 to total rainfall erosivity exceeded 50%. During 1960–2024, R99 and its contribution rate increased in all subregions, with R99 increasing 2.3 and 5.7 times faster than R95 in the Huang–Huai Plain and Sichuan Basin, respectively. R95 and R99 hot spots were concentrated in the Huang–Huai Plain, Middle–Lower Yangtze River Plain, Sichuan Basin, and Wushan Mountains, showing clear regional clustering. During 2000–2020, relatively high–high risk areas increased from 16.90% to 31.78% under R95 and from 16.26% to 25.27% under R99. Risk was dominated by H contributions in the Huang–Huai Plain and Middle–Lower Yangtze River Plain, whereas the Qinling–Daba Mountains remained E-dominated. By 2020, relatively high–high risk areas contained 35.83%–46.97% of GDP and 39.81%42.59% of the population, forming high-risk–high-exposure patterns in the Sichuan Basin, Middle–Lower Yangtze River Plain, and Huang–Huai Plain.