不同方法对南黄海重现波高计算值的影响

采用SWAN波浪模型对江苏南黄海地区1979~2018年共40 a的波况进行模拟及验证,将模拟结果与实测资料进行比对,吻合良好。百年重现波高分布通过基于年极值和月极值的广义极值分布函数(GEV)和超阈值取值方法(POT)的广义帕累托分布模型(GP)计算得出。计算结果表明,不同方法的计算结果在辐射沙洲北部地区差别最大,采用月极值所得重现波高偏小,采用年极值计算的重现波高在辐射沙洲南北外围地区最大,其余地区则以POT方法为大值。在分别采用不同数据长度计算重现波高的试验中得出,取月极值的GEV分布计算结果对时间跨度的改变不敏感,而取年极值受之影响最大,POT方法介于两者之间。

Influence of different methods on calculation of extreme value analysis of significant wave height on South Yellow Sea

The SWAN wave model was used to simulate and verify the wave of the South Yellow Sea of Jiangsu Province from 1979 to 2018.The simulation results agreed well with the measured data.The hundred-year return period wave height distribution was calculated by the generalized extreme distribution function(GEV)based on the yearly extreme value and the monthly extreme value and the generalized Pareto distribution model(GP)based on the super-threshold value method(POT).The result shows that in the northern part of the radial sand ridges(RSR),hundred-year return period wave heights calculated by different methods are the most different.The value calculated by the monthly extreme value is small.The hundred-year return period wave height calculated by the yearly extreme value in the peripheral areas of the north and south of the RSR is the largest,and the POT method is the largest value in the rest.In the experiment of calculating the hundred-year return period wave height with different time spans,the results of the monthly extreme value of the GEV distribution are not sensitive to the change of the time span,and the yearly extremum is most affected,and the POT method is somewhere in between.