三峡工程与两湖河川径流丰枯遭遇研究

基于多种常用的统计技术对三峡工程坝址控制站与两湖入湖控制站天然径流序列进行趋势诊断,识别了其变化趋势;采用多种拟合精度评价方法,从构建的多种边缘分布和Copula联合分布模型中优选出拟合精度较高的模型,计算分析三峡工程与两湖天然径流量丰枯遭遇概率及其变化规律。研究表明:三峡工程坝址控制站径流量呈现不显著下降趋势,两湖入湖控制站径流量呈现不显著增大趋势;三峡工程与鄱阳湖丰枯遭遇概率较洞庭湖略大,全年期三峡工程与洞庭湖、鄱阳湖遭遇同丰同枯概率较汛期、非汛期要大,同丰概率分别为42.10%和44.71%,同枯概率分别为11.74%和16.62%。研究成果可为三峡水库供水调度研究提供理论参考。

Synchronous-asynchronous wet-dry encounter probability of the runoff of Three Gorges Project with Dongting Lake and Poyang Lake

A variety of statistical techniques were used to detect the trend of runoff series from hydrological stations of Three Gorges Project, Dongting Lake and Poyang Lake. According to the results of multiple fitting accuracy estimation methods, the model with higher fitting accuracy was selected from the various marginal distributions and Copula joint distributions, and the wet-dry encounter probability and variation of natural runoff of Three Gorges Project and Dongting Lake and Poyang Lake were calculated and analyzed. The results indicated that the runoff showed an insignificant decreasing trend at Yichang station (Three Gorges Project) and increasing trends at Xiangtan (Dongting Lake) and Waizhou station (Poyang Lake). The wet-dry encounter probability between Three Gorges Project and Poyang Lake is little larger than that of Three Gorges Project and Dongting Lake. The wet-dry encounter probability in the entire year was greater than that in the flood season and the dry season. Synchronous wet probability of the Three Gorges Project with Dongting Lake and Poyang Lake were 42.10% and 44.71%, and synchronous dryness probability were 11.74% and 16.62%, respectively. The study can provide a theoretical reference for water supply dispatching of the Three Gorges Reservoir to alleviate the contradiction between supply and demand in Dongting Lake and Poyang Lake regions.