Numerical Simulation and Risk Analysis of Coastal Inundation in Land Reclamation Areas: A Case Study of the Pearl River Estuary

Coastal inundation results in many human casualties and significant economic losses. In this study, an inundation model with an unstructured mesh was developed using the ADvanced CIRCulation (ADCIRC) and Simulating WAves Nearshore (SWAN) models to simulate 43 inundation events from 1998 to 2018. A combined wind-pressure field derived from the assimilation wind-pressure model was used to drive the coupled ADCIRC-SWAN model. On the basis of the model results, a sensitivity study of the influence of land reclamation on coastal inundation was conducted. The results of the study showed that coastline changes caused by reclamation significantly influence the distribution of coastal inundation, particularly in areas where narrow waterways, bays, and peninsulas are newly formed. Combining the extreme inundation events calculated using the Gumbel and Weibull distributions, the 10-year, 50-year, 100-year, and 200-year return coastal inundations were obtained for the Pearl River Estuary in China. The risk of coastal inundation was analyzed according to the probability of the inundation depth exceeding 1 m. A hazard grade zoning map was drawn to guide disaster relief and mitigation in the reclamation area.