Hindcast Characteristics of Typhoon-Generated Waves near Marine-Ranching Areas Along the Guangdong Coast

This study establishes a numerical wave simulation framework based on Simulating Waves Nearshore (SWAN) to investigate the characteristics of typhoon-generated waves in the coastal waters of the northern South China Sea. To better represent typhoon-wind features in the study area, a blended typhoon wind field was constructed by combining the ERA5 background wind field with a Holland parametric typhoon wind field. The numerical simulations were performed with a spatial resolution of 0.25° × 0.25°. Model performance was evaluated against in situ observations and Jason-3 satellite altimetry data, showing satisfactory agreement regarding significant wave height (Hs). Hindcast simulations were conducted for 50 typhoon events that affected the coastal waters of Guangdong Province, China, during 2013–2025. Eighteen representative points were selected within marine-ranching areas distributed across the western, central, and eastern coastal sectors of Guangdong. Typhoon-wave events occurred most frequently in the central coastal sector, which also exhibited the greatest significant wave heights. In this sector, the maximum significant wave height reached 12.13 m, while the mean significant wave height was 3.37 m. The peak wave energy spectral density decreased from the central sector toward both the western and eastern sectors. In the central sector, the peak wave energy spectral density exceeded 90 m2/Hz, with a domain-wide maximum value of 297.60 m2/Hz. Across all representative points, the peak frequencies ranged from 0.07 to 0.12 Hz. Analyses of typhoon event characteristics, significant wave height features, and wave spectral properties in this study offer background references for marine-ranching planning and regional hazard assessment.