Distribution of Cs-137 in stream sediments and stream banks in the upper Susquehanna basin - 2006

This study expanded on our previous regional study of sediment sources in central New York by using 137Cs and other tracers to quantify the relative importance of sediment producing processes in the upper Susquehanna watershed. We sampled recently eroded sediments in a suite of watersheds in the upper Susquehanna basin of NY with contrasting historical and current land uses, and differing geomorphic and stream channel characteristics, focusing on likely high sediment-producing areas to identify subbasins with high levels of sediment contributed by bank erosion. By fingerprinting stream sediment sources, we hope to improve the basis for conceptualizing the process of erosion and sediment delivery and for devising and implementing effective sediment control programs. The most effective work with sediment tracers has involved the analysis of nuclear bomb-derived and natural fallout radionuclides that bond to sediment. Fallout radionuclides generally are retained in the upper few cm of soil; hence, they can be employed to analyze whether stream sediments have been eroded recently from surface sources or represent erosion from deeper sources like rills, gullies and streambanks. See the following for related work using similar methods: Nagle,G.N., T.J. Fahey, J.C. Ritchie, and P.B. Woodbury. 2007. Variations in sediment sources and yields in the Finger Lakes and Catskills regions of New York. Hydrological Processes 21(6): 828-838. Online: http://hdl.handle.net/1813/766