123-9 Holocene Sediment Budget for a 10^3 Km^2 Drainage Basin

See more from this Division: Topical Sessions
See more from this Session: Sediment in Fluvial Systems: Production, Transport, and Storage at the Watershed Scale I

Sunday, 5 October 2008: 10:25 AM
George R. Brown Convention Center, 332BE

Jon Tunnicliffe and Michael Church, Department of Geography, The University of British Columbia, Vancouver, BC, Canada
Abstract:
Chilliwack River drains 1200 km^2 in the Cascade Mountains on the Washington-British Columbia border. We have assembled a summary sediment budget for the basin by reconstructing the end-glacial (c. 13 000 calendric years BP) topography and determining the eroded sediment volume by DEM differencing. A lake in mid-basin preserves a record of headwater fine sediment yield, whilst alluvial fans throughout the basin, including a large end-point fan, preserve coarse sediments. Using a 1-D model of river and floodplain evolution, constrained by textural, lithological and geochemical tracers, and some absolute dates, we have computed a summary history of sediment yield for the basin that gives insight into the timing of sediment movement and the parameters of the fluvial sediment transport system. The mass balance framework and simplified morphodynamic formulation provide insight into the complex response of the fluvial system following deglaciation.

See more from this Division: Topical Sessions
See more from this Session: Sediment in Fluvial Systems: Production, Transport, and Storage at the Watershed Scale I