SPH evaluation of the hydrodynamic consequences induced by reef degradation

Abstract An apparent increase in the frequency and intensity of natural disturbances and anthropogenic activities accelerates the global degradation of coral reefs. The emergency planning for coastal erosion and flooding along the low-lying coasts fronted by coral reefs underscores the need to predict and evaluate reasonably the hydrodynamic consequences of reef degradation. Here the ability of the well validated Smoothed Particle Hydrodynamics (SPH) porous model is enhanced by integrating a momentum source wave maker for wave groups generation in water of arbitrary depth. Validated results show the SPH model can predict properly the propagation and transformation of wave groups over the complex coral reef. The model is finally adopted to predict the hydrodynamic consequences induced by reef degradation both under the reef resonance and off-resonance conditions. This work provides a general framework for understanding the effects of reef degradation on the spatial distributions of wave setup, wave-induced current and low frequency wave energy over the reef-flat under the action of bichromatic wave groups with different frequency differences.