CHAPTER 164 DECOUPLED NUMERICAL MODEL OF THREE-DIMENSIONAL BEACH CHANGE

This paper describes a numerical model of three-dimensional beach change as produced by breaking waves and wave-induced currents. Cross-shore lines spaced at intervals alongshore form the basic calculation element, and cross-shore and longshore transport rates are calculated independently on the lines. Transport rates are coupled indirectly through the mass conservation equation and a contouring routine that determines local depth contour orientation for calculating wave transformation. The model has reduced calculation time compared to fully gridded hydrodynamic and beach change models, yet allows representation of complex boundary conditions, coastal structures, and movement of longshore bars and berms. Results of two test series are presented, one for the movement and protective functioning of a linear mound constructed of dredged material, and the other for impoundment at a jetty