Evolution of soil rill erosion and its link to extreme precipitation in northeast China's black soil region

<b>Objective:</b> This study aims to evaluate the soil rill erosion intensity in the Northeast Black Soil Region of China and explore the relationship between extreme precipitation events and soil erosion over the period from 1980 to 2020. <b>Methods:</b> The Revised Universal Soil Loss Equation (RUSLE) model was applied to estimate soil rill erosion values using a combination of meteorological observations, remote sensing, soil physicochemical properties, and Geographic Information Systems. A correlation analysis framework was developed to link soil rill erosion values with extreme precipitation indices, and the spatial-temporal dynamics were analyzed. <b>Results:</b> The annual soil rill erosion value in the region averaged 0.84 ± 0.22 t·ha^-1·yr^-1, with no significant trend over four decades. The Eastern Mongolian subregion exhibited the highest erosion rates, exceeding 2.0 t·ha^-1·yr^-1. Strong correlations were identified between soil rill erosion and factors such as consecutive rainy days, cumulative precipitation, and extreme rainfall events. <b>Conclusions:</b> Extreme precipitation events play a significant role in driving soil rill erosion, emphasizing the need for refined models that integrate hydrological processes. The study provides critical insights for regional soil conservation and climate adaptation strategies.