Severe erosion of black soil in Northeastern China has attracted great attention, and more work on soil erosion and soil conservation have been conducted in recent years. However, few studies on physical erosion modeling in this region have been conducted. In the study, 24 reservoir catchments in Baiquan county were selected as study objects, and the 137Cs technique was successfully combined with a soil erosion model WaTEM/SEDEM (Water and Tillage Erosion Model and Sediment Delivery Model). The 137Cs-derived soil erosion intensities were used as input data to run and calibrate the WaTEM/SEDEM model firstly, and then the model was validated using the sediment yields from the 24 reservoir catchments. Soil erosion intensity in the cultivated lands is the highest, averaging 24.5 t/(hm2·a), and the mean erosion intensities in shrub and grass lands are 5.6 and 9.5 t/(hm2·a), respectively. The mean erosion intensity in forest lands is the minimum. The optimal combination of the minimum and maximum Ktc values of WaTEM/SEDEM was 4 m and 8 m, with the highest cNS (Nash-Sutcliffe coefficient) of 0.62. The calibrated model has a robust modeling capacity, and the correlation coefficients of the modeled sediment yield(YS) and the specific sediment yield(YSS) and the observed counterparts are both over 0.70 for the 24 reservoir catchments. This study can provide scientific basis for soil erosion study and conservation measures implemented in the black soil region and other similar regions.

black soil region; soil erosion; nuclear tracing; model; modeling