## 1 Introduction  
A typhoon will cause water to increase or decrease. When a storm surge water increase superimposes an astronomical spring tide, an abnormal rise in seawater level caused by low-pressure systems, such as tropical cyclones, will cause seawater overflow, breakup of seawall, siltation of harbor basin, and obstruction of shipping, resulting in significant economic and human losses, as seen in the cases of Typhoon Katrina and Rita (2005), as well as Hurricanes Ike and Gustav (2008). Moreover, typhoons will also have a certain impact on the flow field of marine water bodies, resulting in the diffusion of marine pollutants. Close to the Northwest Pacific Ocean, China's coastline is frequently affected by storm surges and typhoon disasters. According to data from 1949 to 2018, 42 typhoons landed in Zhejiang Province, China. The super typhoon 0608 reached its maximum wind speed of 68 m/s [1]. At the landing time, the minimum air pressure in the center was 920 HPA, resulting in a direct economic loss of nearly 12.7 billion yuan. Zhoushan City is located in the south of the Yangtze River Estuary and the southeast of Hangzhou Bay. It is a coastal city composed of islands. With the pace of global warming, the frequency and intensity of typhoons have been increasing. Therefore, research into storm surges is of great significance for coastal engineering disaster prevention and reduction. [PERSON] et al. conducted a comprehensive flood risk assessment for wastewater treatment plants in New York City under extreme storm events. They found that the impact of storm surges, high-intensity rainfall, and sea level rise on wastewater treatment plants can be analyzed by considering the percentage of the submerged length of the buildings to the total perimeter of the buildings and the amount of damage [2]. From the 1920s, the causes and manifestations of storm surges were preliminarily analyzed in the world, mainly by means of theoretical research, empirical statistics, and so on. With the continuous development of storm surge theory and prediction, research has entered a period at which the nonlinear coupling theory of edge wave, shelf wave, astronomical tide, and storm surge is proposed. The size of a storm surge depends on many factors, including the size, path, speed, and intensity of the storm system, local nearshore water depth, and the shape of the coastline. Nowadays, with the rapid development of detection and computer technology, research into the mechanism of a storm surge has entered a new era of the combination of numerical simulation and experiment, which makes the results more accurate. With global climate change, more and more evidence has accumulated that storm surge disasters will become more frequent and severe in the future. Nowadays, the Slosh model, Delft3D model, ECMSED model, and ROMs model based on a structured grid, and the ADCIRC model and FVCOM model based on an unstructured grid are widely used storm surge numerical models [3]. The ADCIRC model, coupled with the nearshore wave model SWAN, was used to simulate hurricane-driven coastal circulation and land flooding. [PERSON] et al. [4] applied the ADCIRC + SWAN model to simulate hydrodynamic conditions, and the results indicated that the model accurately predicted wave and surge characteristics. [PERSON] et al. [5] used a real-time unstructured grid (NGO-RT) and the ADCIRC + SWAN model to simulate coastal inundation under the action of multiple hurricanes in the Gulf of Mexico, which improved its operation efficiency. The average absolute difference in the simulated water level ranged from 0.04 to 0.02 m, achieving high accuracy. [PERSON] et al. [6] used ADCIRC to simulate the Aila cyclone in the Bay of Bengal. The simulated water level was in good agreement with the overall statistical data of the four tide stations [7]. ERA 5 is a kind of comprehensive reanalysis of data. [PERSON] used the new ERA5 to analyze a storm surge simulation.