Under climate change, soil erosion on the Loess Plateau has intensified, and the pronounced southeast-northwest gradients in climate, soils, and vegetation have produced marked regional differences in erosion processes. However, the mechanisms underlying these spatial variations remain insufficiently understood. Using seven years of observations from 32 monitoring stations, covering 672 natural rainfall events, hillslope runoff and soil loss were quantified across geomorphically distinct subregions. The result indicates that soil erosion is primarily controlled by rainfall, slope, and land use, while extreme rainfall and inadequate land management substantially amplify erosion risks. From light to torrential rain, runoff depth increased more than ninefold and soil loss more than thirty-fivefold, while bare land produced over seven times more soil loss than forestland. A southeast-northwest transition in dominant controls was identified: runoff generation becomes increasingly rainfalldriven, while the influence of land use and vegetation diminishes. Soil-loss pathways displayed distinct regional patterns-controlled primarily by the joint influence of runoff and land use in sandy regions, by topography-land use interactions in valley plains, and by runoff dynamics in hilly-gully and mountainous areas. Together, these results clarify the key processes underlying spatial variability in dryland erosion and provide a robust framework for assessing erosion risks and supporting adaptive land-management strategies under increasingly extreme climatic conditions.