基于Copula函数的黄海波高周期联合统计分析

为研究黄海中部海域波浪的年极值波高与年极值周期联合分布,基于黄海海域3个位置点1999—2018年SWAN后报波浪数据,采用5种单变量分布拟合年极值波高和年极值周期,通过拟合优度评价得到各位置点年极值波高和年极值周期的最优单变量分布,利用Copula函数理论建立了年极值波高和年极值周期联合分布函数,并与单变量分布波高和周期设计值进行了对比分析。结果表明:黄海中部海域波高周期联合分布可能存在区域性特征；波高周期联合分布得到的波高、周期设计值较同设计频率下的单变量分布设计值高；相同波高和周期设计频率下,单变量重现期最大,条件重现期次之,联合重现期最小。

Joint statistical analysis of wave height and wave period of Yellow Sea based on Copula function

To study the joint distribution of annual extreme wave height and annual extreme period of waves in the central Yellow Sea, five univariate distributions were fitted to the annual extreme wave height and annual extreme period based on SWAN hindcast wave data from 1999 to 2018 at three locations in the Yellow Sea, and the optimal marginal distributions of annual extreme wave height and annual extreme period at each location were obtained through the evaluation of the goodness of fit. The joint distribution function of annual extreme wave height and annual extreme period was established using the Copula function theory, and compared with the univariate distribution of wave height and period design values. The results show that there may be regional characteristics in the joint wave height and period distribution in the central Yellow Sea; the design values of wave height and period obtained from the joint wave height and period distribution are higher than the design values of univariate distribution at the same design frequency; under the same design frequency, the univariate return period is the largest, the conditional return period is the second and the joint return period is the smallest.