基于Copula函数的洪峰流量与洪水历时联合分布研究

Combined Frequency Analysis of Peak and Duration Based on Copula Function

基于Copula函数分析了潖江河大庙峡流域洪峰流量与洪水历时的联合频率分布特征,得出GumbelHougaard Copula函数可较好地拟合2者的相关关系,以及反映2变量在"且"和"或"组合情况下的发生频率和重现期。在同频率设计情况下,2变量发生组合受灾风险的概率很低。在同一重现期下的历时与不同重现期下的洪峰组合频率随重现期的减小而增大,5 a一遇洪峰对应的历时在31.7~40.2 h的可能性较大,10 a一遇的洪峰历时在45 h以上的概率较小。另外,当历时重现期低于200 a一遇时,流域遭遇200 a一遇以上洪峰的概率极低。

Gumbel-Hougaard Copula is used to analyze the joint probability distribution and the simultaneous frequency distribution of the two variables of peak and duration. G-H Copula can also reflect the combined risk probability of two variables. In the case of the same fre- quency, the combined risk probability of peak and duration is very low. The duration of the five year flood is likely between 31.7-40.2 h.The duration of ten year flood is unlikely to occur in more than 45 h. In addition, when the return period is less than 200 years in PA River Basin, the probability of more than 200 year flood is very low.