Distribution Characteristics of the Extreme Storm Tides in the Radial Sand Ridges Area of the South Yellow Sea in China

The aim of this study is to understand the tidal characteristics in the radial sand ridges area (South Yellow Sea, China) considering the most adverse metrological and hydrodynamic condition. Based on data analysis, at least 30% of the annual highest tidal levels in the South Yellow Sea are caused by the combination of storm surge and astronomical spring tides. Among the top 10 extreme high tidal levels, such combinational effects account for over 60%. A 2-D numerical model is applied to study distributions of the extreme high tidal levels influenced by typhoons with various tracks in the South Yellow Sea. Typhoon characteristics are classified into four categories: the front landing, the front leaving, the offshore moving and other types. As such, four different combinations with the same astronomical tide are examined. The front landing and the offshore moving tracks are of specific interest, as they lead to the most significant surge in coastal areas, especially at Jianggang and Liyashan. Temporal-spatial patterns of the extreme storm tides are presented to identify risks of coastal flooding in the radial sand ridges area.