Study On Dam-break Flood Risk Analysis Which Is Induced By Flash Flood In Small And Medium-sized Reservoirs

The dam-break events often have devastating losses, and the dam-break flood riskanalysis which is induced by flash flood in small and medium-sized reservoirs has attractedextensive attention of experts and scholars in all over the world because it occupies therelevant large proportion. The dam-break flood risk analysis and flood losses evaluationmust have been done before the dam construction by the investors and the subject has notstayed just in the technical level. This paper gets the results that all the dam failure eventsare all small and medium sized reservoir dam after collecting and statistically analyzing alldam failure cases in different aspects in23years from1991to2013. The earth-rockfill damhas broken278and the number is96.19%of the total number of dam failure, at the sametime, the most of the dam failures are caused by the sudden storm floods in the mountains.Therefore, the flood risk analysis and the related reasearch of the earth rockfill dam-breakby the flash flood have great value and practical significance. This paper mainly includesthe following several aspects.、Firstly, studying and analyzing causes and its characteristics of the mountain torrentdisaster; collecting national289dam break information from1991to2013, count andanalyze the large amounts of data from the aspects of the year of dam break, provincialdistribution, dam type, project status, height of dam, failure reason; And introducing threetypes which are instantly complete collapse, instantaneous partial collapse, gruadallydam-break.Secondly, On the basis of systematic analysis of flood characteristics in Jiakouwaflood detention basin, this research collects a series of basic information such as thefoundation map, engineering facilities, historical floods and other related materials and setsup a flood routing model in Jiakouwa flood detention basin by using hydraulics method.The parameters of the model are analyzed, calibrated and verified according to the1954and1963historical floods.Thirdly, combining with the practical engeering and taking the Qiyang mountainreservoir in LingWu city as an example, this part applies the reasearch method and thecalculation model to simulate the flood process after dam-break and the flood routingcomputiaton. Using GIS technology, it can realize that intuitive displaying the submergedscope, submerged water depth and other flooding risk factors and evaluating the floodlosses of dam-break.