Inundation simulation of different return periods of storm surge based on a numerical model and observational data

Abstract

China is among the countries most severely affected by storm surge disasters, with substantial economic losses and human casualties inflicted on its coastal areas. Computing inundation from storm surges for various typical return periods (TRPs) can serve as the scientific basis for preparing evacuation maps kin the case of storm surge disasters, conducting spatial planning of coastal cities, and formulating emergency plans. Zhoushan City in Zhejiang Province, China, was selected as the representative case for this study. A high-precision storm surge numerical model was established and historical observation data were used to calculate the probability distribution curves of extreme tidal levels at two representative tide stations within the study area. First, based on historical typhoon and extratropical-cyclone events affecting the study area, a dataset including weather events was used, and extreme tidal levels for the two representative tide stations were deployed to identify weather events that could cause a storm surge for different return periods. Numerical modeling was then used to generate the resulting inundation range and water depth distribution, establishing a method for calculating inundation from storm surge for various TRPs. The proposed method could easily be adopted in various coastal counties and serve as an effective tool for decision-making in storm surge disaster risk mitigation efforts.