Topsoil erosion not only reduces soil productivity but also accelerates atmospheric carbon release, posing a dual threat to soil sustainability and climate regulation.This study quantified soil erosion and associated carbon loss in riparian regions of Korea’s four major rivers under different land uses. A total of 4,414 topsoil samples were collected from the Geum, Nakdong, Yeongsan–Seomjin, and Han River basins. Soil loss was estimated using the Universal Soil Loss Equation (USLE), and carbon loss and emissions were derived from soil organic carbon (SOC) and carbon stock data, assuming 20% carbon release. Average soil loss was highest in the Han River basin (47.99 t ha⁻¹ yr⁻¹), with bare land showing the greatest erosion (90.86 t ha⁻¹ yr⁻¹) and carbon loss (1,209 kg ha⁻¹ yr⁻¹). Forest and grassland exhibited minimal losses (< 30 kg ha⁻¹ yr⁻¹). Carbon loss correlated positively with soil erosion and carbon stock. Severe erosion in riparian zones, particularly in bare and upland areas, leads to substantial carbon depletion. Strengthening vegetation cover and implementing land-use-specific conservation practices are vital to reduce erosion-induced carbon loss.

Keywords: Soil erosion; Carbon loss; Riparian zone; USLE; Topsoil