TRENDS IN STORM SURGE EXTREMES ALONG THE SOUTHEASTERN COAST OF CHINA

Increasing trend in extreme sea levels, caused by the combined effects of mean sea level, storm surges and high tides, can have devastating impacts on coastal communities. Previous studies agree that sea-level rise has been a considerable driver of trends in extremes sea levels since at least 1960 (Rohmer and Le Cozannet, 2019), however, long-term changes in storm surges, which are associated with changes in the intensity, occurrence, and paths of storms and low-pressure systems, are more unclear (Dangendorf et al., 2014). In the most recent study by Calafat et al. (2022), it was found that trends in surge extremes can make comparable contributions to the overall change in extreme sea levels in Europe, which is crucial for coastal adaptation in a changing climate. Along the coast of China, trends in extreme surges remain unclear owing to the sparsity of measurement data. In this study, hydrodynamic modelling was setup to reconstruct the storm surges along the southeastern coast of China from the year 1979 to 2019. Trend analysis was then carried out at both tide gauges and along the continuous coast. Possible cause of the spatiotemporal change in storm surge extremes was also analyzed.