宁夏典型流域淤地坝系运行风险评价

病险坝会严重地威胁到人民生命和经济财产安全,因此淤地坝运行风险的识别和研究尤为重要.选取宁夏西吉县车路沟坝系为研究对象,分别提取并建立一套相对完整的单坝及坝系运行风险评价指标体系,结合改进层次分析法计算指标权重,对各坝7个暴雨重现期下的运行风险及坝系300年一遇情景下的运行风险进行了评价.结果表明:随着重现期的增加,车路沟、前咀骨干坝以及东庄湾中型坝的风险等级发生了不同程度的变化,需重点关注;当遭遇300年一遇暴雨时,西吉车路沟流域运行风险值由高到低依次是:王昭单元＞前咀单元＞流域坝系＞大坪单元＞盘路湾单元,各淤地坝单元以及流域坝系均处于运行安全状态.本研究整体上实现了单坝,淤地坝单元以及流域坝系的运行风险评价,为该地区的淤地坝安全预报预警提供一定的借鉴和参考.

Evaluation on the operation risk of dam system in the typical watersheds of Ningxia

Background]Dilapidated dam will seriously threaten people's life and property safety,therefore,the identification and research of check dam's operation risk is particularly important.Methods] Selecting Chelugou dam system of Ningxia as the research object,a set of relatively complete evaluation index system of operation risk of both single dam and the whole dam system were extracted and established respectively from four aspects of engineering,management,economy and structure.With the method of improved AHP (Analytic Hierarchy Process) to calculate the index weight,the operation risk of single dam under seven different storm return periods and that of the whole system under the return period of 300 years were calculated and evaluated comprehensively,meanwhile the risk map of temporal and spatial distributionof single dam was made as well.Results] For the operation risk of single dam,it showed that there were three check dam including Chelugou,Qianzu and Dongzhuangwan,which operation risk grade grew from class Ⅲ (generally dangerous stae) under the occuring period of 10 years to class Ⅱ (dangerous state) under the occuring period of 50 years,100 years,300 years,which need to be taken seriously.On the whole,the project and economic risk of single dam in Chelugou dam system were generally high,which exceeded 0.8 and 0.4 perspectively,that was related to,the majority of dam in Ningxia was given priority to water storage.For the evaluation of dam system,when suffered a heavy rain of period 300 years,the operation risk of Chelugou basin from high to low were as follows:Wangzhao unit(0.51,classⅢ) ＞ Qianzu unit(0.50,classⅢ) ＞ the whole basin(0.44,classⅢ) ＞ Dapin unit (0.39,class Ⅳ) ＞ Panluwan unit (0.35,class Ⅳ),meaning that all dam unit were in the generally dangerous state or generally safe state.And from the view of whether dam system unit or the whole basin,the basin were all in a safe state of operation.It could also been seen from the results that the key dam unit was the Wangzhao unit and Qianzu unit which influenced the operation safety of the whole dam system.In addition to building spillway,it was necessary to deal with the damaged parts of dam body as well as water release works as soon as possible to eliminate hidden dangers.Conclusions] The paper realized the evaluation work of operation risk of single dam,check dam unit as well as the dam system on the whole.These results would provide certain reference to the safety forecast warning of check dam in the region and help the administrative department of rapid decision-making,so as to ensure the safe and stable operation of check dam and lay the foundation for establishing the safety emergency response mechanism and operation measures.