基于Copula函数的浙江沿海流域雨潮组合风险分析

受暴雨与外江潮位共同影响,沿海地区防洪排涝问题异常复杂,传统的单变量水文频率分析已无法解决复杂的实际防洪排涝问题。为此,采用了二维Copula函数进行暴雨和潮位的二维联合概率计算,并基于同现风险率、条件风险率和防涝风险率进行风险分析,最终应用于浙江省多个沿海流域的雨潮遭遇分析。应用结果表明:Copula函数能够较好地模拟浙江省沿海流域的雨潮联合分布,准确定量地计算出不同雨潮组合下的风险率,且该方法分析成果与传统的洪潮遭遇分析成果基本一致,具有较强的可靠性和实用性。

Risk analysis of rainfall and tide combination in coastal areas of Zhejiang Province based on Copula function

Under the interacted influence of heavy rain and river tide, the flood control and drainage problems in coastal areas are very complicated, and the traditional univariate hydrological frequency analysis method can not solve the complicated problems. In this paper, the two-dimensional copula function is used to calculate the combination probability of rainstorm and tide level. Based on co-occurrence risk rate, conditional risk rate and waterlogging risk rate, the two-dimensional copula function is applied to the rainfall- tide encounter analysis of several coastal basins in Zhejiang Province. The results show that the copula function is appropriate to simulate the joint distribution of rainfall and tide in coastal basin of Zhejiang Province. It can calculate the risk rate accurately and quantitatively under different combination of rainfall and tide, and the results are basically consistent with the results of the traditional flood-tide encounter analysis, indicating that the copula function method has high reliability and practicability.