A coastal wind-decay model for typhoon wind-speed estimation and infrastructure risk in complex coastal terrain

Accurate near-coastal typhoon wind-speed estimation is essential for resilient coastal infrastructure. This study developed a Coastal Wind-Decay Model (CWDM) that integrates a Holland parametric wind-field model, CFD-derived terrain amplification, and an empirically optimized near-coastal attenuation. Calibrated using observations from 20 typhoons (1951–2020) in Zhejiang Province and externally tested across 57 events in four southern coastal provinces of China (Fujian, Guangdong, Hainan, and Zhejiang), the framework reproduces rapid 0–20 km coastal decay and the influence of complex terrain. Relative to single model, CWDM reduces RMSE from 7.18 to 6.47 m/s (≈9.9%) and improves agreement with observed wind-speed distributions across coastline types. Validation against Typhoon Hagupit shows close correspondence between predicted high-wind corridors and recorded transmission-tower failures, supporting pre-event risk mapping and targeted reinforcement. By linking mesoscale vortex simulations with local-scale hazard assessment while maintaining computational efficiency, CWDM provides an operational pathway for wind-resistant design and emergency planning in typhoon-prone regions.