考虑历史洪水不确定性的峰量联合频率分析  

Joint frequency analysis of flood discharge and volume considering uncertainties of historical flood events

作　　者：尚晓三[1,2] 王栋 王远坤[1] SHANG Xiaosan;WANG Dong;WANG Yuankun(Department of Hydrosciences,School of Earth Sciences and Engineering,Nanjing University,Nanjing 210093;Anhui Survey and Design Institute of Water Conservancy&Hydropower Company Limited,Hefei 230088)

机构地区：[1]南京大学地球科学与工程学院水科学系,南京210093 [2]安徽省水利水电勘测设计研究总院有限公司,合肥230088

出　　处：《水力发电学报》2021年第5期35-43,共9页Journal of Hydroelectric Engineering

基　　金：第二次青藏高原综合科学考察研究资助(2019QZKK0203);国家自然科学基金(41571017,91647203)。

摘　　要：洪水事件一般具有多个特征属性,多变量联合分析可以全面分析洪水过程的统计特征。本文依据Copula函数,建立考虑定量和非定量历史洪水的不连续序列峰量联合洪水频率分析模型,选用遗传算法对模型参数进行寻优,并采用最可能组合法和同频率组合法计算不同重现期设计洪水,通过变化置信区间分析历史洪水不确定性变化对参数估计与设计洪水的影响。以长江干流宜昌水文站为研究案例,结果表明,将历史洪水考虑为不定量时,其参数估计结果更为合理,更符合洪峰和时段洪量之间的关系。设计洪水值随着历史洪水置信区间的增加而降低,并随着重现期的增加,下降幅度更大。Generally,flood events have several characteristic attributes,and the time variations in these attributes can be comprehensively analyzed using multivariate flood frequency analysis.This study develops a peak discharge-flood volume joint frequency analysis model for discontinuous sequences based on the Copula function,considering both quantitative and non-quantitative historical floods and using a genetic algorithm to estimate the model parameters.And the influence of uncertain changes in historical floods on parameter estimation and design floods is analyzed.This model is applied in a case study of the Yichang hydrologic station that has a systematic gauge record and a historical flood record.Results show that parameter estimation is more reasonable when the peak discharges of a historical flood event are described using confidence intervals with lower and upper bounds,and in this case the estimates of flood frequency analysis agree better with the field observed relationship of peak discharge versus flood volume.The peak discharge of the design flood is decreased with an increase in its confidence interval,and the decrease becomes larger at a longer recurrence period.

关 键 词：COPULA函数 多变量联合频率分布 洪水频率分析 遗传算法 历史洪水 宜昌水文站 

分 类 号：TV122[水利工程—水文学及水资源]