Research on high-resolution storm surge simulation and early warning along the coast of Tianjin

The process of storm surge increase along the coast of Tianjin is significantly influenced by the coupling effect of typhoon path, coastal terrain, and astronomical tides. To enhance the ability to forecast and defend against regional storm surge disasters, a high-resolution storm surge numerical model for the Tianjin coastal area was constructed based on the MIKE21 Flow Model coupled with the Young & Sobey typhoon wind field model. Simulation studies were conducted using the typical case of Typhoon "Khanun"(No. 2306). The results show that the simulated tide level is in good agreement with the measured tide level,the correlation coefficient is 0.91, and the root mean square error is 0.12 m. There is a significant spatial difference in the storm surge surge in Tianjin coastal area. Affected by the topographic bottleneck effect, the maximum surge in the Haihe River estuary area can reach 2.8 m, which is significantly higher than the eastern mudflat area; Different typhoon paths have a significant impact on high tide levels and inundation ranges, with the maximum water level reaching 4.2 meters in the northwest path scenario, exceeding current flood control standards; Based on the simulation results, a hierarchical warning scheme for storm surge zoning along the Tianjin coast was further constructed, which can provide technical support for regional flood control and drought resistance, port operation safety, and coastal protection engineering.