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Journal article
A watershed scale spatially-distributed model for streambank erosion rate driven by channel curvature
Geomorphology (Amsterdam, Netherlands), Vol.294, pp.146-161
10/01/2017
Web of Science ID: WOS:000413610200011
Abstract
Streambank erosion is a major source of fluvial sediment, but few large-scale, spatially distributed models exist to quantify streambank erosion rates. We introduce a spatially distributed model for streambank erosion applicable to sinuous, single-thread channels. We argue that such a model can adequately characterize streambank erosion rates, measured at the outsides of bends over a 2-year time period, throughout a large region. The model is based on the widely-used excess-velocity equation and comprised three components: a physics-based hydrodynamic model, a large-scale 1-dimensional model of average monthly discharge, and an empirical bank erodibility parameterization. The hydrodynamic submodel requires inputs of channel centerline, slope, width, depth, friction factor, and a scour factor A; the large-scale watershed submodel utilizes watershed-averaged monthly outputs of the Noah-2.8 land surface model; bank erodibility is based on tree cover and bank height as proxies for root density. The model was calibrated with erosion rates measured in sand-bed streams throughout the northern Gulf of Mexico coastal plain. The calibrated model outperforms a purely empirical model, as well as a model based only on excess velocity, illustrating the utility of combining a physics-based hydrodynamic model with an empirical bank erodibility relationship. The model could be improved by incorporating spatial variability in channel roughness and the hydrodynamic scour factor, which are here assumed constant. A reach-scale application of the model is illustrated on similar to 1 km of a medium-sized, mixed forest-pasture stream, where the model identifies streambank erosion hotspots on forested and non-forested bends. (C) 2017 Elsevier B.V. All rights reserved.
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Details
- Title
- A watershed scale spatially-distributed model for streambank erosion rate driven by channel curvature
- Publication Details
- Geomorphology (Amsterdam, Netherlands), Vol.294, pp.146-161
- Resource Type
- Journal article
- Publisher
- Elsevier
- Number of pages
- 16
- Grant note
- Geological Society of America Florida Fish and Wildlife Conservation Commission University of West Florida Scholarly and Creative Activities Committee 13058 / U.S. Fish and Wildlife Service (State Wildlife Grant); US Fish & Wildlife Service Gulf Coast Association of Geological Societies
- Copyright
- © 2017 Elsevier B.V. All rights reserved.
- Identifiers
- WOS:000413610200011; 99380491194206600
- Academic Unit
- Hal Marcus College of Science and Engineering ; Earth and Environmental Sciences
- Language
- English