Validating the use of caesium-137 measurements to estimate erosion rates in three small catchments in Southern Italy

The fallout radionuclide caesium-137 (137Cs) has been increasingly used in recent years to assess soil erosion and deposition at the catchment scale. However, the successful application of the 137Cs approach depends heavily on the availability of reliable conversion models for converting measurements of 137Cs redistribution to estimates of soil redistribution rates. This paper reports the results of a study aimed at validating the use of a theoretical conversion model to convert measurements of 137Cs inventories on uncultivated soils to estimates of soil erosion rates. It is based on three small catchments located in Calabria, Southern Italy, for which measurements of sediment output are available. By comparing the estimates of net soil loss from the catchments derived from 137Cs measurements with the measured sediment output, it is possible to assess the accuracy of the former estimates. The general corresp-ondence between the measured sediment yields and the estimates of net soil loss based on 137Cs measurements, confirms the validity of the theoretical model used for converting 137Cs measurements into estimates of soil redistribution rates.