3‐D Model of Bathymetric Response to Structures

Abstract

A fully implicit finite‐difference, N‐line numerical model is developed to predict bathymetric changes in the vicinity of coastal structures. The wave field transformation includes refraction, shoaling, and diffraction. The model simulates the changes in N‐contour lines due to both longshore and onshoreoffshore sediment transport. A new equation for the distribution of sediment transport across the littoral zone is applied. The model is capable of simulating one or more shore‐perpendicular structures, movement of offshore disposal mounds and beach fill evolution. The structure length and location, sediment properties, equilibrium beach profile, etc., are user‐specified along with the wave climate. Results are presented for two example cases, sediment transport of dredge disposal in the vicinity of Oregon Inlet, and simulation of the Longshore Sand Transport Study at Channel Islands Harbor, California. These examples demonstrate the model's ability to simulate various physical situations and that the model predicts realistic shoreline changes.