Coupling Analysis of Storm Surge and Wind Wave on Coastal Flood in the East China Sea during Typhoon Chan-Hom in 2015

Typhoon Chan-hom moved across the continental shelf in East China Sea with peak wind speed up to 58 m/s, exciting huge storm surge and wind-wave along the coast and shelf. A high resolution coupling models (ADCIRC+SWAN) was applied to simulate and study the dynamical evolution and flooding processes. The skill of the coupling models in reproducing the storm surge, wind-wave and tide processes was well validated by measurements of wave buoys and tide gauge. Significant surge-wave interactions are evidenced by comparing simulations and measurements. Numerical analysis results indicated that wave setup induced by wave radiation stress accounts for 26% of the local peak surge. Coupling analysis showed a significant effect of the typhoon waves on the storm-induced coastal flooding, for that the maximum flooding area increased by 12%. The impact of the dike height on coastal flooding was examined. The results highlight the importance of the coupling effect on coastal flood risk analysis.