Measuring the ~ ~137 Cs reference inventory in study area accurately and establishing quantitative models for converting ~~ ~137 Cs measurements to estimates of soil redistribution rates are two key questions. The spatial variation of erosion and deposition of Black Soils on a sloping cropland in Northeast China was studied using ~ ~137 Cs tracer technique. In filed, three transects perpendicular to the contour were set and five slope units for each transect were located, including a summit, shoulder-slope,...