NUMERICAL MODELING OF NEARSHORE MORPHOLOGICAL CHANGES UNDER A CURRENT-WAVE FIELD

Abstract

This paper presents a time-dependent 3-D nearshore morphological response numerical model which includes the slope effect, undertow current, wave-borne transport, and transition zone effect. These effects are very important but often not estimated in other sediment transport models. By including the cushioning effect in the water column, which prevents the advection of turbulence generated by wave breaking from the surface to the bottom, this model is shown to be able to approach an equilibrium state of sediment transport. The computed cross-shore and longshore sediment transport rates are calibrated based on the large wave tank data, 3-D basin experiments, and available sediment transport formulas. The predicted changes ofbottom topography near structures and inlet in physical model are compared for model verification.