| In China over80thousand reservoirs of all types have been built, putting the countryin the world’s first place in number of dams. Reservoirs and dams have created hugesocial and economic benefits in terms of flood control, water supply, powergeneration, irrigation, etc.. However, since1949there have been more than3,400damfailures, causing tremendous loss of human lives and economy. With fast growth ofpopulation and accelerated progress in urbanization in the latest years, the lossbrought about by dam failures also escalated rapidly, making dam safety an issue ofmore importance. Consequently, study of dam behavior in prevention of dam failure,and flood analysis as well as computation and simulation of the analytical results, areof great necessity for formulation of regional flood control emergency action plansand enhancement of regional flood control and disaster mitigation measures.Nevertheless, in China, study in techniques for numerical simulation of dam breakfloods is far less systematic and in-depth, and can thus hardly provide effectivedecision-making ground for dam safety management. Therefore, more in-depthresearch needs to be done in numerical simulation of dam break floods, so as to usethe method to disclose the hydrodynamics features of dam break floods undercomplex conditions, to provide a theoretical and technical basis for establishment of adam failure risk analysis and disaster assessment system, and to provide scientificdecision-making reference for effective implementation of flood control and disastermitigation measures.This paper, with dam break floods as the target of study, briefly introduces theprevailing approaches for, and achievements in, research of dam break floods,generally describes one dimensional and two-dimensional research theories，and byemploying a2-D dam break flood research method based on shallow water waveequations, presents a2-D dam break flood numerical model, including numericaldiscreteness, stability conditions and boundary treatment. Based on the theories forresearch of dam break floods, a dam break parameter model is established andanalyzed, giving an estimate of break formation time and peak flows and combiningthe interrelations between the peak flows and all other parameters. A further study isconducted on the most harmful instantaneous floods to analyze instantaneous flowcontrol equations, and to present a method for computation of dam break floods uponinstantaneous full-break. Taking as an example one hydropower project in China’sSichuan Province, the paper uses2-D numerical simulation method to predict its dambreak floods, and, by mainly study of potential failure scenarios, attains the computingresults such as peak dam break flows and scope of inundation. It is further suggestedthat a flood control risk mechanism and warning system should be established andreinforced to make full use of the hydrological forecast network in the reservoir areaand strengthen dam operation management, so that emergency action plans for floodcontrol and disaster mitigation are better in place. Conclusions and proposals are reached in the end that2-D dam break flood research method can effectively analyzeand simulate the process of dam break and flood inundation, and has greatsignificance for flood control and disaster mitigation, and that serious attention oughtto be paid to research of dam break floods and improvement of corresponding floodcontrol and disaster mitigation measures. |
