Redistribution of caesium-137 by erosion and deposition on an Australian soil

Abstract

Caesium-137, a nuclear fallout product which is carried down to the ground by rainfall and becomes tightly adsorbed to soil particles, is being used to study soil erosion and accumulation. The measurement of 137Cs activity in soil cores in an upland catchment on the Darling Downs has revealed a vertical and areal distribution of this isotope which is in general agreement with expectations based on the topography, the observed erosion and deposition sites, the variation in 137Cs fallout through time, and hypotheses of 137Cs redistribution. Such information may allow the development of a practical technique for estimating soil erosion and accumulation rates using this isotope; it also allows testing of mathematical models of erosion/deposition processes.