Objective The Huicheng Basin constitutes a key ecological part of the Western Qinling Mountains within China's north-south transitional zone. This study aims to analyze the spatiotemporal variation characteristics of soil erosion and identify the associated driving factors within this region, thereby offering a scientific reference for implementing soil and water conservation and ecological civilization initiatives in the region.

Methods Huixian county in the Huicheng Basin of the Western Qinling Mountains was selected as the research area. The Revised Universal Soil Loss Equation (RUSLE) model was utilized to evaluate the spatiotemporal patterns of soil erosion at the county scale. Additionally, the optimal parameters-based geographical detector (OPGD) model was employed to investigate the driving factors of soil erosion variation.

Results 1) The results indicated that between 2000 and 2020, both the soil erosion modulus and the total soil erosion amount exhibited a significant downward trend. Slight erosion emerged as the predominant form of soil erosion, with its distribution gradually expanding over the study period. 2) Significant variation of soil erosion was observed across different land use types, slope gradients, and elevations. Among these, grasslands demonstrated the lowest soil erosion modulus and amount. The mid-elevation zone, ranging from 1 000 to 1 500 meters above sea level, experienced the highest intensity of slight and moderate-to-severe soil erosion. In areas where the slope gradient exceeded 25°, a substantial increase in the soil erosion modulus and amount was recorded. Conversely, when the slope gradient surpassed 35°, the area affected by all intensity grades of soil erosion significantly decreased. 3) Vegetation coverage was determined to be the primary factor influencing the spatial variation of soil erosion, with a contribution rate exceeding 34%. The interactions among various factors were found to exert a more pronounced influence on the spatial variation of soil erosion than single factors. In particular, the interactions between vegetation coverage and other factors significantly enhanced the impact on soil erosion.

Conclusions In Huixian county, soil erosion exhibits distinct spatiotemporal variation. Soil erosion modulus and amount are found to have declined over time, with slight erosion becoming the dominant type. This trend suggests an improvement in soil and water conservation status. The study concludes that vegetation elements and their interactions with other factors must be taken into account in soil and water loss control strategies.