Submitted to: Soil Erosion for 21st Century Symposium
Publication Type: Proceedings
Publication Acceptance Date: October 30, 2000
Publication Date: N/A
Technical Abstract: Fallout Cesium-137 from nuclear weapons tests was deposited worldwide during the 1950's and 1960's. Once Cs-137 reaches the soild surface, it is strongly and quickly adsorbed by the fine soil particles. Any movement of Cs-137 across the landscape is, therefore, associated with the movement of soil particles making Cs-137 an effective tracer of soil erosion. By comparing Cs-137 inventory in a soil profile with the inventory of a reference soil profile (a nearby soil profile with no soil erosion), it is possible to estimate soil erosion rates (Cs-137 inventory less than that in the reference profile) or within field redeposition (Cs-137 inventory greater than in the reference profile). Theoretical models have been developed to calculate soil erosion rates and soil redistribution patterns based on Cs-137 inventory in soil profiles collected in the field. Cs-137 methodology gives information on soil loss or gain at specific sites in the efield. Examples of soil loss and redeposition patterns are given to illustrate the use of the technique. Over a quarter of a century of research, development, and applications has clearly demonstrated that radioactive fallout Cs-137 can be used efficiently and effectively as a tracer for the redistribution of soil particles on the landscape.