Abstract:
The frequency of strong typhoons landing or seriously affecting Zhejiang has increased, and the number of northward shifts has increased in recent years. Typhoons threaten the economic activities of Zhoushan Island and neighboring islands more and more, so it is necessary to carry out researches on storm high tidal level around the coast of Zhoushan island. We have analyzed the distribution of the storm high tidal level caused by the Typhoon In-Fa that has the greatest impact on the sea zone of Zhoushan since the beginning of this century. The measured tidal data and the simulated result of storm surge by the model constructed reveal that the storm high tidal level caused by the Typhoon In-Fa overall is low in the east and high in the west of the sea zone, accompanied by the characteristics of the central low-value area, which is related to the central low-value area of the astronomical high tide level. The difference of storm high tide level during the Typhoon In-Fa in the sea area of the island can reach more than 0.5 m. If the Typhoon In-Fa lands at astronomical high tidal level, the storm high tidal level at Dinhai and Daishan will increase by 0.1~0.4 m. If it moves southward to the Damutu location and lands at the high tide level, it will cause a higher storm high tide level around the island, which exceeds the actual storm high tide level by 0.2 to 0.8 m. Great attention should be paid to the regional variability and changing characteristics of storm surge high tide levels, which is conducive to improving regional defense capabilities of storm surge disasters.