Spatiotemporal Features of Storm Surge Activity and Its Response to Climate Change in the Southeastern Coastal Area of China in the Past 60 years

The present study investigates the temporal and spatial variation of storm surge activity at different temporal scales using reconstructed daily maximum storm surge levels in the southeastern coastal area of China for the past 60 years. Considering the surge height and the duration of storm surge, the comprehensive intensity of storm surge is proposed, namely Accumulated Storm Surge Potential Impact. The results show that with the intensification of climate warming, the intensity has increased rapidly, although the overall the frequency and duration of storm surges have not changed significantly. In relation to the spatial distribution of storm surge intensity, storm surge at different time scales (interannual and decadal) was mainly located in the areas of concentration of historical tropical cyclones landing and in subconcentration areas. In terms of climate change response, it is clear that the frequency, duration, and intensity of storm surges have increased significantly since the end of the 1980s. From the perspective of the spatial distribution of the climate tendency rate (it reflects the change trend of regional climatic elements) of storm surge intensity, the areas of increased intensity are mainly located in several concentrated areas where storm surge events occur frequently, while the weakened areas are also other areas where storm surges have rarely occurred. El Nino-Southern Oscillation events have a certain effect on the frequency, duration, and intensity of storm surge activity, although the effect on intensity is more significant. The impact of the Pacific Decadal Oscillation on the frequency, duration, and intensity of storm surge activity at different phases was also different, with clear regional distribution features for each phase. In this way, we can make targeted preparations for disaster prevention and mitigation, and avoid further socio-economic losses.