Abstract:To investigate the statistical characteristics of wind and waves during typhoon processes, based on 40-year (1979-2018) hindcast wave data and reanalysis wind speed data, the wind speed and significant wave height data during periods of significant typhoon influence at three study sites in the northwestern South China Sea were extracted using trajectory tracking and time matching methods. The joint distribution characteristics of wind speed and wind direction, as well as significant wave height and wave direction, were analyzed, and the delay characteristics of wind and waves during typhoon processes were examined. Furthermore, based on the extreme value theory, the maximum significant wave height and maximum wind speed samples during each typhoon process were extracted. Based on the three-parameter Weibull distribution model and Copula model, the extrapolated values for 50-year, 100-year, 150-year, and 200-year return periods under univariate and joint return periods were calculated. The results indicate that in the northern part of the study area, strong waves exceeding 6.0 m driven by typhoons are mainly distributed in the 33.75°-123.75° sector, and the time difference between the peak wind speed and peak significant wave height in the study area is mainly concentrated in 0-20 h. Because a broader risk range is considered, the extrapolated values of the joint return periods are greater than those of the univariate return periods.