Predicting Bed Scour on the Continental Shelf during Hurricane Andrew

A numerical sedimentation model, TRANS98, has been used to simulate storm sedimentation on Ship Shoal, a drowned barrier island on the Louisiana continental shelf. The model predicts that maximum sediment resuspension and transport occurs over a few tens of kilometers during the storm peak. Sediment transport is dominated by suspended load rather than bed load. The total resuspension and erosion depth is more than 0.02 m over Ship Shoal. A method of estimating the error in the computed wave-current shear stress is presented. The predicted shear stress during the storm peak is underpredicted by 9%. The error estimate increases to more than 16% overprediction after the eye made landfall. The error estimates suggest that the model-predicted sediment resuspension and potential transport patterns are reasonable.