基于Copula函数的铁山港雨潮遭遇组合分析

Combination Analysis of Rain Tide Encounter in Tieshan Harbour Based on Copula Function

以铁山港地区为例,在函数优度评价方法的基础上,分别选择皮尔逊Ⅲ型和广义Pareto分布为雨量以及相应潮位的边缘分布模型,并结合图形评价法,选择GH Copula函数构建暴雨和潮位的联合分布,考虑雨潮组合设计重现期,并引入二次重现期的概念,通过对比传统重现期和二次重现期在不同雨潮组合下的差异,得到二次重现期相对于传统重现期定义的雨、潮危险事件范围更广、更安全,并分析不同暴雨潮位组合下的同现风险率、条件风险率,为铁山港防洪治理规划提供科学依据。

Taking Tieshan Harbor Area as an example,based on the function superiority evaluation method,P-Ⅲtype and generalized Pareto distribution are selected as the edge distribution models of rainfall and corresponding tide level respectively.Based on the graphic evaluation method,GH copula function is selected to construct the joint distribution of rain and tide level,the return period is designed by considering the combination of rain and tide,and the concept of secondary return period is introduced.By comparing the differences between the traditional return period and the secondary return period under different combinations of rain and tide,it is obtained that the range of rain and tide dangerous events defined by the secondary return period is wider and safer than that defined by the traditional return period,and the occurrence risk rate and conditional risk rate under different combinations of rain and tide levels are analyzed so as to provide a scientific basis for the flood control planning of Tieshan Harbor.