Study on The Mechanism of Beach Morphodynamic Response to Storms under The Tidal Influence

Few previous studies on beach response to storms have considered the effect of the tidal process, and the studies on beach process under storm wave-tidal coupling action are evidently insufficient. Based on the various storm response in the South China coast with different tidal ranges, this proposal incorporates tidal fluctuation into the research on beach storm effect, with a combined method of field observation, physical model and numerical simulation. This project will focus on: the study of storm wave propagation under the influence of tidal fluctuation, including storm wave spectrum, wave energy distribution and wave-induced current distribution, which will be used to explore the  coupling process of tides and storm surges; the study of the spatial-temporal variation of inundation height and its component, which will be used to explore the modulated mechanism of tidal level on inundation height; the study of beach response to storms in typical geomorphic unit under the coupling effect of tidal process, storm surges and storm waves, which will be used to explore the wave energy dissipation capacity of sand bars, the adaptation of beach faces and sediment exchange with coastal foredunes. Based on the above researches, the storm-induced beach process under the tidal influence will be revealed, and a beach morphodynamic mode driven by the coupling effects of tides, waves and storms will be established. This research breaks through the insufficient understanding of traditional storm processes in wave-dominated beaches, and its results might be applied to the prediction and the risk assessment of beach storm disasters, which provides theoretical basis and technical support for the prevention and mitigation of coastal storm surge disasters.