Using environmental radionuclides as tracers in sediment budget investigations

The many problems associated with the presence of fine sediment in river basins has generated an increasing need for an improved understanding of the mobilization, transfer and fate of such sediment, in order to plan appropriate sediment management and control strategies. The sediment budget concept affords a valuable framework for assembling information on the sediment response of a catchment, but it is difficult to assemble the data required to construct a reliable sediment budget. The use of environmental or fallout radionuclides offers considerable potential for developing improved understanding and characterization of catchment sediment budgets. The basis for using caesium-137, unsupported lead-210 and beryllium-7 as tracers in sediment budget investigations is outlined, and examples of the use of these radionuclides in studies of soil erosion and sediment delivery from agricultural land, flood plain sedimentation and associated sediment conveyance losses, and sediment source fingerprinting are provided.