The 24th IAHR-APD Congress (24th IAHR-APD Congress)

130 / 2024-02-18 15:58:54

Numerical study on the effects of wave-current interaction for typhoon-induced storm surges: a case study of “Chan-hom”

storm surge; wave-current interaction; coupled model; typhoon

Based on the FVCOM hydrodynamic model and the FVCOM-SWAVE wave model, this study constructs a wave-current coupled storm surge model for the Bohai, Yellow, and East China Seas during the typhoon "Chanhom". On the basis of good verification of surge elevations and significant wave height, the influence of wave-current interaction on storm surge is quantified and key dynamic factors are revealed. This study indicates that in near-shore shallow waters, the wave-current interaction has a significant impact on surge elevations, contributing to approximately 14% of the water level at the peak surge. During high tide periods, wave-current interaction tends to decrease the surge elevations, while during low tide periods, it tends to cause surge level increase.Taking wave-current interaction into account, the simulation results of significant wave height are more consistent with the observations. In addition, the contributions of tide-surge interaction, wind field, and pressure to surge elevation are also compared. The wind field plays a leading role in surge elevations, with its influence concentrated in the coastal waters of Zhejiang Province and Hangzhou Bay. The maximum surge elevations can reach up to 2 m. In the open sea area, the air pressure dominates the surge elevations within the range of typhoon center. However, in the coastal waters, especially at the head of Hangzhou Bay, the non-linear tide-surge interaction and wave-current interaction can significantly influence the surge elevations. The maximum surge elevations can reach 1.2 m and 0.5 m, respectively. These research findings can provide valuable insights for coastal disaster prevention and mitigation.