Problems in determining spatial inhomogeneity of 137Cs fallout for estimating rates of erosion-accumulative processes

The issues of assessing variability of 137 Cs fallout of global and Chernobyl origin at reference sites are discussed with a purpose to use this isotope as a tracer for estimating the rates of erosion-accumulative processes. It is shown that local variability of soil contamination by 137 Cs at reference sites is within 7–20%, which makes it possible to use the isotope as a tracer. When studies are conducted within drainage basins, the available trend of the atmospheric 137 Cs fallout should be taken into account in assessing the soil and sedimentation redistribution.