Three-Dimensional Near-Shore Bar Morphology

A numerical morphological model has been applied to investigate the initiation and development of along-shore variations in a long-shore bar (morphological instability). Two cases have been studied: a case where bar generating effects are included starting with an initially plane bed (Q3D) and a case where an otherwise stationary bar — uniform in the alongshore direction — is used as the initial topography (2DH). In both cases the morphological evolution of the slightly perturbed initial states is simulated beyond the initially linear stage. In the Q3D case a long-shore bar was formed with the bar crest significantly meandering down the coast. The bar crest did not seem to develop any (rip) channel like features. In the 2DH case on the other hand the bar tended to break up forming channels.