HR: 16:45h
AN: OS24A-04    [Abstracts]
TI: Sediment transport in the inner-surf and swash zones
AU: * Hsu, T
EM: thsu@whoi.edu
AF: Woods Hole Oceanographic Institution, Applied Ocean Physics and Engineering, Woods Hole, MA 02543 United States
AU: Raubenheimer, B
EM: britt@whoi.edu
AF: Woods Hole Oceanographic Institution, Applied Ocean Physics and Engineering, Woods Hole, MA 02543 United States
AB: Sediment transport in the inner-surf and swash zones is modeled with two-phase equations [Hsu et al. 2004, Proc. Royal Soc. Lond. A, 460, p2223-2250] that have been extended to predict movement of fine sand. Comparisons of predicted velocity and sediment concentration profiles with observations collected in a U-tube suggest that given closures for fluid turbulence, particle intergranular forces, and fluid-particle interactions in the boundary layer, the two-phase model is capable of simulating sheet flow processes, including both bedload and suspended-load transport and the phase lag between the flow forcing and the bottom stress. Predictions of simpler models that neglect the suspended load transport or that assume a quasi-steady bottom stress with respect to the flow forcing are evaluated by comparison with the two-phase model predictions. Preliminary simulations driven with velocities measured during the SwashX experiment (Fall 2000) suggest that the phase lag between the flow forcing and the bottom stress is important to transport driven by sea-swell dominated swash, but is negligible for transport driven by infragravity-dominated swash. Predictions of suspended sediment transport are sensitive to the effects of breaking-wave-generated turbulence on the boundary layer. Funding of this research is provided by ONR and NSF.
DE: 4546 Nearshore processes
DE: 4558 Sediment transport
SC: Ocean Sciences [OS]
MN: 2004 AGU Fall Meeting