Integration of a Simple Bimodal Bedload Transport Law for Nearshore Morphodynamics
Abstract
Processes of granular sorting affect the spatial distribution of sediments, bedform evolution, and ultimately large-scale bathymetric changes (such as sandbar migration). Of additional interest is the prediction of hazardous contaminant transport and diffusion in coastal regions. We present results from the initial phase of development of a quasi-3D bimodal coarse sediment transport (BCST) module using a simple power law for bedload transport of bimodal distributions of coarse grains that will predict the temporal and spatial evolution of seabed surface granular roughness and morphology. For all shoreline geometries and wave energies initially tested, the bimodal mass ratio demonstrates a general fining of material near and around the breaking point (15-40m offshore), with a coarsening toward the swash zone. Given the known sensitivity of both nearshore wave and circulation models on the specification of grain size, these initial findings suggest that a more thorough study of the evolution of grain size distribution is required. The BCST module is intended to be runtime interactive with established coastal wave and circulation models and/or to act as a guide for modifications to established sediment transport modules.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2006
- Bibcode:
- 2006AGUFMOS41C0621T
- Keywords:
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- 0545 Modeling (4255);
- 4217 Coastal processes;
- 4255 Numerical modeling (0545;
- 0560);
- 4546 Nearshore processes;
- 4558 Sediment transport (1862)