Background  Exploring the spatiotemporal characteristics of soil erosion and its relationship with topographic factors in typical areas of the Tongbai Mountain region can provide valuable insights for regional water conservation and comprehensive soil erosion management.

Methods  This study focuses on Tongbai county in the Tongbai Mountain region. It uses the Chinese Soil Loss Equation to quantitatively analyze the spatiotemporal characteristics of soil erosion from 2018 to 2022, and examines the topographic effects on soil erosion in terms of elevation, slope, and aspect.

Results  1) The area of mild and above soil erosion in the study region has continuously decreased, with a reduction rate of 5.26%, and mild, extremely severe, and severe erosion all showed a declining trend; 2) Mild and above erosion primarily occurs at elevations of > 0-400 m and slopes of > 2°-15°. The proportion of soil erosion area decreases with increasing elevation and initially increases and then decreases with increasing slope, with no significant differences in distribution across aspects; 3) Elevation and slope have a significant impact on the spatial distribution of soil erosion. Under the same aspect conditions, the coefficient of variation for soil erosion decreases with increasing elevation, and the differences gradually widen. As slope increases, the coefficient of variation initially rises and then falls, transitioning from positive to negative. The elevation-slope effect is more complex: with increasing slope, soil erosion tends to increase >800 m in elevation, but the growth rate diminishes, while < 800 m, soil erosion first increases and then decreases.

Conclusions  In the study area, soil erosion is more likely to occur at elevations < 400 m and within a slope range of > 6°-15°, with the elevation-slope effect having the greatest impact on soil erosion.