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Quantifying relative contributions from sediment sources in Conservation Effects Assessment Project watersheds
- Wilson, C.G., Kuhnle, R.A., Bosch, D.D., Steiner, J.L., Starks, P.J., Tomer, M.D., Wilson, G.V.
- Journal of soil and water conservation 2008 v.63 no.6 pp. 523
- agricultural watersheds, conservation practices, USDA, conservation programs, governmental programs and projects, sediment yield, bank erosion, water erosion, radionuclides, radiolabeling, Mississippi, Georgia, Iowa, Oklahoma
- A technique using the relationship between the naturally occurring radionuclide tracers, (7)Be and (210)Pb(xs), was used to differentiate eroded surface soils and channel-derived sediments in the fine suspended sediment loads of runoff events in five Conservation Effects Assessment Project watersheds. A simple two end-member mixing model was used to determine the relative contribution from each source. Results suggest that eroded surface soils were more prevalent in the suspended load early in a runoff event, but channel contributions dominated the suspended load at later stages. The method proved useful for multiple sites due to a constant proportion of the atmospheric deliveries of the two radionuclides globally. Use of only two radionuclide tracers simplifies the differentiation of sediment sources within a watershed but limits precision.