Objective As an important ecological barrier in the middle reaches of the Yangtze River, the spatiotemporal variations in soil erosion in Hunan province are directly linked to the construction of regional ecological security patterns, which is of great significance for revealing its driving mechanism and maintaining regional ecological security.

Methods Based on the Revised Universal Soil Erosion Equation (RUSLE) model, and by comprehensively using methods including geodetector, transfer matrix, and spatial autocorrelation analysis, this study systematically revealed the spatiotemporal evolution patterns of soil erosion and their driving mechanisms in Hunan Province from 1990 to 2020.

Results 1) Over the past 30 years, soil erosion in Hunan Province was dominated by slight and mild levels (accounting for 91.63%), while the moderate and above levels accounted for only 8.37%. The multi-year average soil erosion modulus was 2 091.87 t/(km²·a). 2) Soil erosion exhibited distinct spatial clustering characteristics. The "high-high" clustering areas were mainly located in the Wuling Mountain area of western Hunan, the northern foothills of the Xuefeng Mountains, and the western side of the Luoxiao Mountains. The "low-low" clustering was concentrated in the Dongting Lake Plain, the valley plain in the middle and lower reaches of the Xiangjiang River, and the alluvial plain of the lower reaches of the Yuanjiang River. 3) The dominant landform type, characterized by large undulating mountains, was the leading factor influencing the spatial patterns of soil erosion in Hunan province (explanatory power q = 0.056), and its interaction with slope gradient has the most significant driving effect on the erosion patterns (q = 0.069). The area of moderate and above erosion exhibited fluctuating changes, mainly driven by multiple extreme rainstorm events within the region. High-risk areas were characterized by medium to high slopes (6.32°−27.80°), high silt content, an altitude of 557−1 980 m, and low NDVI (0.559−0.598).

Conclusions Soil erosion in Hunan province is generally mild. Soil erosion control should focus on the mountainous areas with medium to high slope gradients and silty soil in western and eastern Hunan, with an emphasis on vegetation restoration and engineering measures. The research findings can provide a scientific basis for the prevention and control of soil erosion and the construction of ecological security in Hunan province.