September 3, 2002
John C. Warner (email@example.com), USGS Woods Hole Field Center
Figure 1. Model bathymetry.
Model bathymetry has a sloping bottom as shown in figure 1. Simulations were conducted for 3.0 days. For this simulation, the bottom orbital velocities, wave period, and direction were obtained from a steady-state solution of the model SWAN. For the hydrodynamic simulation, the wave field results from SWAN were increased from 0 to their maximum values with a hyperbolic tangent function that reached maximum value at 10 hours. The surface stress was held constant until a total of 40 hours have elapsed, when the stress was decreased hyperbolically for 10 hours. The simulation continued until all sediment had settled from the water column.
Cross sectional plot of velocity contours at x = 25 km is shown in figure 2, at maximum wind stress. A downwind surface flow of near 32 cm/s is observed in the shallow region, with a compensating upwind flow at depth of 24 cm/s. Figure 3 shows the final bathymetric change. The majority of the sediment was transport from the southwest corner towards the northeast corner, due to the counter clockwise circulation from the westerly wind stress.
Figure 2. Along channel velocity contours (cm/s) at x = 25 km. Positive velocity is out of the page (downwind flow), negative into the page (upwind flow).
Figure 3. Plan view of final bathymetric change.