Summer Seasonal Sea-level Rise and Associated Potential Storm Surge Vulnerability of the West Coast of Korea

Typhoon-induced storm surge usually occurs during the summer season. Thus, it is important to account for seasonal sea-level (SL) rise in coastal hazard mitigation. In this study, we analyzed one hour intervals of tidal records for Incheon (INC), Kunsan (KUN), and Mokpo (MOK) stations, located on the West Coast of Korea (WCK), as well as atmospheric pressure, to determine the correlation of SL fluctuations as they relate to the inverse barometer effect. Results exhibited annual (summer) sea-level rise (SLR) of 0.35 (0.32), 0.39 (0.39), and 0.55 (0.53) cm/year at the three stations, respectively. However, the mean SL (MSL) during the summer season was approximately 20 cm higher than the annual MSL. It was found that seasonal atmospheric pressure highly affected SL, with 1.58-1.73 cm per hPa owing to the inverse barometer effect; however, there were phase lags in the summer of one month or more. Although the nodal factor accounted for +/- 3.7% of the M-2 tidal amplitude over 18.6-year return period, the resulting M2 amplitude was maximized in 2090 at 2.87 m, 2.14 m, and 1.62 m at the three reference stations, owing to the macro-tidal environment of the WCK than in 2100. Thus, the target year associated with global warming and SLR, which is normally 2100, should be shifted one decade prior to ensure effective coastal storm surge vulnerability hazards analyses.