HR: 1340h
AN: H43E-1672    [Abstracts]
TI: Improved Fluvial Geomorphic Interpretation Derived From DEM Differencing
AU: * Wheaton, J M
EM: Joe.Wheaton@aber.ac.uk
AF: Centre for Catchment and Coastal Research, Institute of Geography and Earth Science, University of Wales Aberystwyth, Llandinam Building, Aberystwyth, SY23 3DB, United Kingdom
AU: * Wheaton, J M
EM: Joe.Wheaton@aber.ac.uk
AF: School of Geography, University of Southampton, Shackelton Building Highfield, Southampton, S017 1BJ, United Kingdom
AU: Brasington, J
EM: jtb@aber.ac.uk
AF: Centre for Catchment and Coastal Research, Institute of Geography and Earth Science, University of Wales Aberystwyth, Llandinam Building, Aberystwyth, SY23 3DB, United Kingdom
AU: Brewer, P A
EM: pqb@aber.ac.uk
AF: Centre for Catchment and Coastal Research, Institute of Geography and Earth Science, University of Wales Aberystwyth, Llandinam Building, Aberystwyth, SY23 3DB, United Kingdom
AU: Darby, S
EM: S.E.Darby@soton.ac.uk
AF: School of Geography, University of Southampton, Shackelton Building Highfield, Southampton, S017 1BJ, United Kingdom
AU: Pasternack, G B
EM: gpast@ucdavis.edu
AF: Department of Land Air and Water Resources, University of California at Davis, One Shields Avenue, Davis, CA 95616, United States
AU: Sear, D
EM: D.Sear@soton.ac.uk
AF: School of Geography, University of Southampton, Shackelton Building Highfield, Southampton, S017 1BJ, United Kingdom
AU: Vericat, D
EM: ddv@aber.ac.uk
AF: Centre for Catchment and Coastal Research, Institute of Geography and Earth Science, University of Wales Aberystwyth, Llandinam Building, Aberystwyth, SY23 3DB, United Kingdom
AU: Williams, R
EM: richard.williams@jbaconsulting.co.uk
AF: JBA Consulting, Ltd., South Barn Broughton Hall, Skipton, BD23 3AE, United Kingdom
AB: Technological advances over the past two decades in remotely-sensed and ground-based topographic surveying technologies have made the rapid acquisition of topographic data in the fluvial environment possible at spatial resolutions and extents previously unimaginable. Consequently, monitoring geomorphic changes and estimating fluvial sediment budgets through comparing repeat topographic surveys (DEM differencing) has now become a tractable, affordable approach for both research purposes and long-term monitoring associated with river restoration. However, meaningful quantitative geomorphic interpretation of repeat topographic surveys has received little attention from either researchers or practitioners. Previous research has shown that quantitative estimates of erosion and deposition from DEM differencing are highly sensitive to DEM uncertainty, with minimum level of detection techniques typically discarding between 40% and 90% of the predicted changes. A series of new methods for segregating reach-scale sediment budgets into their specific process components, while accounting for the influence of DEM uncertainty, were developed and explored to highlight distinctive geomorphic signatures between different styles of change. To illustrate the interpretive power of the techniques in different settings, results are presented from analyses across a range of gravel-bed river types: a) the braided River Feshie, Scotland, UK; b) the formerly gravel-mined, wandering Sulphur Creek, California, USA; c) a heavily regulated reach of the Mokelumne River, California, USA that has been subjected to over 5 years of spawning habitat rehabilitation; and d) a restored meandering channel and floodplain of the Highland Water, New Forest, UK. Despite fundamentally different process suites between the study sites, the budget segregation technique is in each case able to aid in more reliable and meaningful geomorphic interpretations of DEM differences.
DE: 1825 Geomorphology: fluvial (1625)
DE: 1847 Modeling
DE: 1862 Sediment transport (4558)
DE: 1873 Uncertainty assessment (3275)
DE: 1895 Instruments and techniques: monitoring
SC: Hydrology [H]
MN: 2007 Fall Meeting