Abstract: Rapid sea level rise caused by global warming presents a significant contemporary challenge for humanity. Anticipated mild coastal inundation events triggered by previous storm surges are projected to reoccur in forthcoming astronomical spring periods. Through a systematical analysis of the historical tidal data from long-term monitoring stations along the Jiangsu's coastline (Lianyungang and Lusi), this paper first establishes a correlation between the occurrence of high-tide-flooding (HTF) along the coastal zone and the water levels above the thresholds that can trigger coastal flooding. Then, we examine how these statistical methodologies affect the results of threshold exceedance categories for HTFs, total sample sizes, temporal continuity within sample time series, and their sensitivity to relative sea-level-rise rates. The results demonstrate that the established model in order to predict the number of HTF days with high water levels exhibits good stability, and the HTF occurrence frequencies are insensitive to different threshold categories at the determined water levels exceeding the industry-standard thresholds. An increase in the sample data size spanning at least 14 years' hourly tidal measurements leads to more stabilized predictions of the future HTFs—rendering them less reliant on temporal consistency or duration within the years sampled. A comparative analysis reveals heightened responsiveness to the sea level rise rate at the Lianyungang station compared with Lusi Port. This study offers methodologies and conclusions useful for the Jiangsu coast and other coasts of China to prepare for coastal inundation stemming from sea level rise.

Key words: sea-level-rise, coastal flooding, high tide, astronomical spring tide, sample analysis