黔江洪水峰量组合概率研究

Study on Probability of Qianjiang Flood Peak Volume Combination

对黔江洪水的洪峰和洪量组合概率进行研究,以期为流域洪水防治提供参考。选取Gumbel-Hougaard Copula函数建立黔江武宣水文站洪峰和洪量的联合分布函数,提出以概率密度函数最大推求多变量水文概率的峰量设计值,并采用该方法对条件组合概率、同现概率、联合概率(或现概率)、二次概率的峰量值进行了计算。结果表明,相同重现期下推求的峰量设计值从大到小依次为联合概率(或现概率)、单变量概率、条件组合概率、二次概率和同现概率,这与各水文概率描述的危险域大小是相符的。基于概率密度函数最大推求的峰量组合值对应最可能情形,可为流域洪水风险管理、水利工程设计提供新的选择。

The paper studied the probability of flood peak and flood volume combination of the Qianjiang River,providing reference for flood control.The Gumbel-Hougaard Copula function was selected to establish the joint distribution function of flood peak and flood volume at the Wuxuan Hydrological Station in Qianjiang River.It was proposed to calculate flood peak and flood volume when the probability density function value of joint distribution was maximum.Conditional combination probability,co-occurrence probability,joint probability,and quadratic probability were adopted to calculate flood peak and flood volume with the method.The results show that the values of flood peak and flood volume under the same return period are in order of joint probability,univariate probability,conditional combination probability,quadratic probability and co-occurrence probability.They are consistent with the sizes of danger zone described by various probabilities.The most likely combination of flood peak and flood volume provides a new option on the flood risk management and engineering design.