HR: 0800h
AN: OS21B-1213 [Abstracts]
TI: Studying the Effect of Wave Shape and Beach Geometry on Longshore Sediment Transport With the NearCoM
Nearshore Model
AU: * Check, L A
EM: lcheck@gtsav.gatech.edu
AF: Georgia Institute of Technology- Savannah, 210 Technology Circle, Savannah, GA 31407-3039
United States
AU: Haas, K A
EM: khaas@gtrep.gatech.edu
AF: Georgia Institute of Technology- Savannah, 210 Technology Circle, Savannah, GA 31407-3039
United States
AU: Hanes, D M
EM: dhanes@usgs.gov
AF: USGS Pacific Science Center, 400 Natural Bridges Drive, Santa Cruz, CA 95060
United States
AB:
The present study investigates longshore sediment transport for a variety of bathymetric and wave conditions using the
NearCoM Nearshore Model developed through the NOPP project. The motivation for the study is to utilize the model predictions
for hydrodynamics and longshore transport under various conditions and evaluate the usefulness of the well known CERC
formula for longshore sediment transport. The model is used to determine the effects of wave shape and bathymetric
variability on the resulting time-varying and total longshore sediment transport. The wave drivers, REF/DIF1 and REF/DIF-S,
are used to assess the effects of monochromatic and spectral waves on longshore sediment transport respectively. SHORECIRC
is used as the circulation module. Longshore transport computations are made with and without skewness terms in the wave
velocity, shear stress, and velocity moments. The longshore sediment transport is calculated using a generic physics based
method and formulas by Bailard (1981, JGR), Watanabe (1992, ICCE), and Ribberink (1998, Coastal Engineering). The transport
results for each scenario are compared to several empirical formulas for longshore sediment transport.
The bathymetries tested include an equilibrium beach profile, a cusped beach, and a barred beach. The longshore transport on
the equilibrium beach profiles is modeled for multiple grain sizes. The longshore sediment transport is modeled for varying
cusp and bar geometries with both monochromatic and spectral wave drivers. The barred beach is modified to compare
transport between waves breaking at, before, and after the bar.
DE: 4255 Numerical modeling
DE: 4546 Nearshore processes
DE: 3020 Littoral processes
DE: 3022 Marine sediments--processes and transport
SC: Ocean Sciences [OS]
MN: 2004 AGU Fall Meeting