Cause of storm surge in Bohai Bay

Storm surge is an abnormal rise of sea level caused by disastrous weather systems such as tropical cyclones (mainly including typhoons, strong tropical storms and tropical storms) or temperate cyclones (cold waves). According to the characteristics of weather systems that induce storm surges, they are usually divided into two types: typhoon storm surges caused by typhoons and temperate storm surges caused by temperate cyclones. Typhoon storm surge is more common in summer and autumn, and its characteristics are fierce, fast, strong and destructive. Typhoon storm surges occur in all marine countries and coastal areas affected by typhoons. Temperate storm surges mostly occur in spring and autumn, and also occur in summer. Its characteristics are: the process of increasing water is relatively stable, and the height of increasing water is lower than that of typhoon storm surge.

In spring and autumn, the Bohai Sea and the northern part of the Yellow Sea frequently encounter cold air and cold waves and strong winds in winter, and storm surges may occur throughout the year. Storm surge has become one of the most serious natural disasters affecting the sustainable development of social economy.

Because the Bohai Sea and the Yellow Sea are located in high latitudes, the disasters are mainly temperate storm surges, and occasionally typhoon storm surges occur, while the southeast coast is dominated by typhoon storm surges. The coastal sections with high disaster rate and serious disasters are mainly concentrated in the following coastal sections: Bohai Bay to Laizhou Bay (mainly temperate storm surge); Jiangsu Xiaoyang estuary to central Zhejiang (including the Yangtze River estuary and Hangzhou Bay); Fujian Ningde to Minjiang estuary coast; Shantou, Guangdong to the Pearl River Estuary; East coast of Leizhou Peninsula; The northeast coast of Hainan Island. These areas include: Tianjin, Shanghai, Ningbo, Wenzhou, Taizhou, Fuzhou, Shantou, Guangzhou, Zhanjiang, Haikou and other coastal cities, especially several national development zones: Binhai New Area, Yangtze River Delta, West Coast of the Taiwan Strait, Pearl River Delta and so on. Are located in the coastal areas with severe storm surge disasters.