基于Copula函数的甬江流域雨潮遭遇组合分析

Encounter Analysis of Flood and Tide of Yongjiang River Basin Based on Copula Function

雨潮遭遇组合分析和组合方式的选取是沿海地区防洪治涝规划的重要内容之一。以甬江流域为例,在考虑尾部相关性的基础上,采用Gumbel Copula函数构建流域暴雨和河口潮位的联合概率分布,分析不同暴雨潮位组合下的同现风险率、条件风险率和组合风险率,并基于条件最可能组合原理,计算给定设计暴雨条件下潮位的条件最可能值和置信区间。结果表明,当甬江流域发生10、20、50、100年一遇暴雨时,相应镇海站最可能发生4、8、21、43年一遇潮位。

Analysis of combination of flood and tide and selection of combinational way are important for flood control and waterlogging planning of coastal areas. Based on the tail dependence, Gumbel Copula function was applied to generate joint distribution of rainfall and tide of the Yongjiang river basin. Simultaneous risk probability, conditional risk probabil- ity and combined risk probability were analyzed under different combinations of rainfall and tide. Conditional most likely values and confidence intervals of tide for the given rainfall were calculated based on conditional most likely combination. The result indicates that the tide of Zhenhai station for 4, 8, 21 and 43 years is most likely to occur when the rainfall of the Yongjiang river basin for 10, 20, 50 and 100 years occurs.