Morphological Evolution Characteristics of a Nourished Beach Under Multi-project Influence and Coupled Wave-current Interaction

Abstract:

In order to investigate the morphological evolution characteristics of the nourished beach， the sediment transport and morphological model was applied and well verified against the measured data on the base of the well-validated wave-current coupled hydrodynamic model using the double nested grid technology. The model results and the measured beach profiles indicate some characteristics of the sediment concentration and the beach morphology： the sediment concentration distribution under the coupled tidal current and normal waves is consistent with that under the coupled tidal current and strong waves， and the averaged sediment concentration and the sediment concentration difference between post- and pre-engineering are larger at the maximum ebb than flood； in post-engineering scenario， the high sediment concentration area locates on the onshore side of the sandbars under the normal waves and on the offshore side under the strong waves； in post-engineering scenario， the erosion and deposition takes place at the sandbars and at the onshore area respectively， and the sandbars move onshore， which indicates that the nourishment project can protect the beach regardless of whether a storm surge occurs.

Key words:multi-engineering;wave-current coupling;beach nourishment;morphological evolution