Spatial differentiation characteristics of soil erosion in central Yunnan Province based on RUSLE model

Based on multi-source high-resolution data (precipitation, soil properties, Digital Elevation Model, Normalized Difference Vegetation Index, and land use) and the Revised Universal Soil Loss Equation (RUSLE), this study systematically assessed the spatial distribution characteristics of soil erosion and the coupling mechanisms of key factors across the entire Central Yunnan region.The results indicate that: (1) Soil erosion characteristics: The total soil erosion amount in Central Yunnan reached 202.19 × 10⁶ t·a⁻¹, exhibiting a spatially heterogeneous feature of "dispersed area coverage but concentrated erosion volume". Minor erosion dominated in area (44.6%), representing the most prevalent erosion type. Moderate and intense erosion collectively contributed 65.73% of the total erosion amount, serving as the primary sediment source. High-intensity erosion (extreme and severe) occupied only 2.7% of the area but accounted for 14.74% of the total erosion amount. (2) Slope gradient effects: Slope gradient exhibited a significant positive correlation with soil erosion modulus. Slopes of 5°～25° were identified as critical threshold zones for concentrated erosion area and volume, necessitating prioritized erosion control measures. (3) Soil and water loss dynamics (Excluding minor erosion), the soil erosion area totaled 5.95 × 10⁶ hm², accounting for 39.67% of the regional land area—significantly exceeding Yunnan Province's average (24.84%), highlighting the urgency of ecological governance. (4) Land use implications: Soil erosion was predominantly concentrated in forestland and grassland (88.48%), followed by cultivated land (11.3%), Forests grasslands and arable lands are the primary land categories contributing to sediment yield in the region and represent the core areas for erosion control and prevention.To address these challenges, a three-tier comprehensive management system should be established, integrating "natural restoration through remote mountain conservation" "ecological restoration of forest-grassland on mid-slopes" and "sloping farmland improvement". The findings of this study provide a scientific basis for the comprehensive decision-making on soil and water loss prevention and control in the Central Yunnan region, as well as for the differentiated management of ecologically fragile areas in plateau mountain regions.