基于同频率法的清江上游干流洪水组合分析

Combined flood analysis of main stream in upper Qingjiang River based on same frequency method

清江上游地区干支流水情复杂,且存在已建控制性调蓄工程。为确定清江姚家平水利枢纽防洪库容需求,利用同频率法分析了湖北省恩施市上游清江干流多区间洪水组合。结果表明,清江上游干流共有4种组合洪水工况:①大龙潭坝址与姚家平坝址发生同频率洪水,上区间发生相应洪水;②大龙潭坝址与上区间发生同频率洪水,姚家平坝址发生相应洪水;③大龙潭坝址相应洪水与姚家平坝址发生同频率洪水,上区间发生相应洪水;④大龙潭坝址相应洪水与上区间发生同频率洪水,姚家平坝址发生相应洪水。最后选取了有代表性的1982年7月、1989年7月、1996年7月洪水作为洪水地区组成分析的典型代表,推求了不同情况下姚家平水利枢纽坝址设计洪水。研究成果可为恩施市城区防洪调度提供参考。

The water flow of main and branch rivers in upstream Qingjiang River was complex,and there were already built control storage projects.In order to determine the demand for flood control storage capacity of Yaojiaping Water Control Project on the Qingjiang River,we used the same frequency method to analyze the multi-interval flood combination on the main stream of the Qingjiang River in the upper reaches of Enshi City,Hubei Province.The results indicated that there were four operating conditions for the combined flood of the upper reaches of the Qingjiang River.①The Dalongtan Dam site and Yaojiaping Dam site experienced floods of the same frequency,with corresponding floods occured in the upper section;②The same frequency of floods occurred at the Dalongtan Dam site and the upper section,while corresponding floods occurred at the Yaojiaping Dam site;③The corresponding floods at the Dalongtan Dam site occurred at the same frequency as those at the Yaojiaping Dam site,with corresponding floods occurring in the upper section;④The corresponding floods at the Dalongtan Dam site occurred at the same frequency as those in the upper section,while the corresponding floods occurred at the Yaojiaping Dam site.Finally,the representative floods of July 1982,July 1989,and July 1996 were selected as typical representatives for the analysis of flood area composition,and the design floods of the Yaojiaping Water Conservancy Complex dam site under different working conditions were calculated.The research results can provide a reference for flood control scheduling in urban areas of Enshi City.