考虑历史洪水资料的三峡水库运行期非一致性设计洪水估算  

Non-stationary design flood estimation of Three Gorges Reservoir in operation period considering historical information

作　　者：谢雨祚 郭生练[1] 熊立华[1] 王俊[1] 钟斯睿 杨媛婷 XIE Yuzuo;GUO Shenglian;XIONG Lihua;WANG Jun;ZHONG Sirui;YANG Yuanting(State Key Laboratory of Water Resources Engineering and Management,Wuhan University,Wuhan 430072,China)

机构地区：[1]武汉大学水资源工程与调度全国重点实验室,湖北武汉430072

出　　处：《水利学报》2024年第6期643-653,共11页Journal of Hydraulic Engineering

基　　金：国家重点研发计划课题(2022YFC3202801);国家自然科学基金长江联合基金项目(U2340205)。

摘　　要：水利水电工程规划设计采用单站的天然年最大洪水系列资料和P-Ⅲ型适线法推求设计洪水,确定水库特征水位。然而上游水库的建成运行,破坏了下游洪水资料系列的一致性假定。本文通过构建非一致性洪水频率分析时变矩模型,计算了长江上游重点水库群的水库系数;并根据连续型随机变量分布函数单调递增的特性,提出了基于Q-Q图的时变P-Ⅲ型适线法;推求出考虑历史洪水资料的三峡水库运行期非一致性设计洪水,并与极大似然法的估算成果进行比较。结果表明:①水库系数作为时变P-Ⅲ型分布的协变量,可以反映洪水系列的非一致性变化规律;②时变P-Ⅲ型适线法侧重考虑历史洪水点据的拟合,拟合效果优于极大似然法;③相较原设计成果,三峡水库运行期1000年一遇设计洪峰Q m、洪量W 3d和W 7d削减18%左右,洪量W 15d和W 30d削减14%左右,长江上游水库群的调蓄作用直接影响三峡水库运行期的防洪库容和特征水位。At-site natural annual maximum flood series and the Pearson TypeⅢ(P-Ⅲ)distribution curve fitting method are used to estimate flood quantiles and determine the reservoir characteristic water levels in the planning and design stage of water conservancy and hydropower projects.However,the stationary assumption of flood data series has been destroyed because of the construction and operation of upstream reservoirs.In this paper,a time-varying moment model for non-stationary flood frequency analysis was built,and the Reservoir Index(RI)of key large-scale reservoirs in the upper reaches of the Yangtze River was calculated.Based on the monotonically increasing property of the distribution function of the continuous flood variable,the time-varying P-Ⅲcurve fitting method was proposed to fit the Q-Q plots.The non-stationary design floods during operation period of the Three Gorges Reservoir(TGR)were inferred and compared with those of the maximum likelihood(ML)method.The results show that:(1)The RI effectively reflects the non-stationarity of flood series,serving as covariates in the time-varying P-Ⅲmodel;(2)The time-varying P-Ⅲcurve fitting method yields a smaller AIC value than the ML method,indicating a better fitness for historical flood series;(3)Compared with the original results,The non-stationary design flood peak,along with the 3-day and 7-day flood volume of TGR are decreased by about 18%,while the 15-day and 30-day design flood volumes are decreased by about 14%.These results demonstrate that the regulation of the cascade reservoirs in the upper Yangtze River directly affects the flood control capacity and characteristic water level of TGR during operation period.

关 键 词：设计洪水 非一致性 不连序系列 时变矩法 水库系数 P-Ⅲ型适线法 极大似然法 三峡水库 

分 类 号：TV122.3[水利工程—水文学及水资源]