Impact of Sampling Approach and Hydraulic Topsoil Properties on Soil Erosion Estimates by the Fallout Radionuclide 7Be

摘要

There is growing interest in the application of the natural fallout radionuclide 7Be as a soil erosion and sediment tracer. Development of robust datasets is, however, hampered by unquantified variability in its vertical distribution within surface soil. Models that convert 7Be inventory measurements to soil erosion estimates are all based on the observed depth distribution of 7Be, described by the relaxation mass depth (ho) parameter. Previous work, however, has not considered potential spatial variation in ho linked to variability in soil physical properties, which could have major implications for the reliability of soil erosion estimates.