Reservoir Flood Control Classified Forecast Dispatching Mode And Risk Analysis

It is fact that flood and waterlog disaster is frequent in China and contradiction between drought and flood is standing out, because of country's location and water resources characteristics. With the development of society economy, water conflict between supply and demand is more serious and water problem will become the main focus problem which will restrict economy and society development in 21 century. In order to lessen the contradiction on water resources and reduce the disaster on flood and drought, turning flood water into usable water resources will be a quite important measure. As one of the important non-engineering measure, reservoir flood control dispatching has great significance on flood safety, water resources addition and reservoir integrated benefits exertion. So researching on reservoir flood control dispatching theory will have great significance.Reservoir flood control dispatching theory includes two parts: flood control regulations design and real time flood control operation. Real time flood control operation is to dispatch flood processes using available information and developed technologies to satisfy the requirement of flood control and water supply. It takes dispatching regulations and flood control restricting parameters as basic which are made in flood control regulations design period. So regulations design is the base of real time operation, while real time operation is the implement of regulations design. So designing scientific, reasonable and exercisable regulations and making it correspond with available information is the key problem to real time reservoir flood control operation.Now neither general dispatching mode nor forecast dispatching mode considers weather system information and both of them select one kind of typical flood process to make one set of dispatching regulations which don't correspond with available information and are poor exercisable. So researching new reservoir flood control dispatching mode is necessary.Reservoir flood control classified forecast dispatching mode belongs to regulations design period. Through analyzing the comparability between weather systems typing and rainstorm flood processes, flood processes can be clustered. Then dispatching regulations corresponding to every weather system typing can be made. By classified forecast dispatching mode, not only the safety of reservoir flood control can be ensured, but flood water utilization ratio can be raised. Thus, basing on original reservoir flood control dispatching theory, classified forecast dispatching mode relying on weather system typing has been studied in this dissertation. The main research and results are as follows:(1) Flood classification theory and method study. Flood classification is the basic to classified forecast dispatching mode research. After discussing classification theory development and methods research, classification theory is used in flood classification study. Then flood classification theory and methods have been given, also flood classification research system has been given, too. Relying on flood classification research system, the research contents of this paper are determined. This chapter provides theory basic for follows research.(2) Feasibility analysis on designing and implementing classified forecast dispatching mode. Weather system identification and flood forecast precision are the key conditions to design and implement classified forecast dispatching regulations. So weather system identification validity and availability is analyzed, also the effect of flood forecast error on regulations design is discussed combined with example. Through analyzing calculation results, flood forecast information available rules are summarized. Lastly, according to the analyzing and calculating results and combined with original dispatching mode design and implement experience, the basic conditions to design and implement classified forecast dispatching regulations are given.(3) Flood forecast methods study under different input data conditions. Flood forecast information is one of the essential conditions to reservoir to implement classified forecast dispatching regulations. In foretime, flood forecast information use is under the hypothesis that remote measuring system can work well and all the rain information can be acquired. While remote measuring system may not work well in practice because many incidental factors, which makes no flood forecast information acquired. In order to ensure flood forecast information acquirement, flood forecast methods with different rain data have been studied. Especially, to the most disadvantage condition that all the remote measuring system is bad and there is only dam station rain flow information available, the author provides improved corresponding rising difference model flow forecast method and flow forecast revising formula. Through application in Dahuofang reservoir, the forecast precision of methods and flood forecast information feasibility in implementing reservoir flood control classified forecast dispatching mode is proved.(4) Flood classification study basing on weather systems information. According to the theory that there is comparability between weather systems and corresponding flood processes at certain watershed, the author discusses flood classification methods relying on weather systems. Combining with Dahuofang reservoir and Beliuhe reservoir, the flood classification methods are used and at the same time the floods classification results reasonability are proved. Examples classification results in this chapter are the basis of following research.(5) Design on classified forecast dispatching mode and regulations. After discussing the necessary of designing and implementing classified forecast dispatching regulations, on the basis of original research results and combining with the basic theory and assume of classified forecast dispatching mode, the author gives the design approach and method of designing classified forecast dispatching regulations. Taking Dahuofang reservoir and Biliuhe reservoir as examples to design classified forecast dispatching regulations and analyze the raised limited water levels in flood period.(6) Risk analysis on designing classified forecast dispatching mode. Risk analysis is the key problem to design and implement classified forecast dispatching regulations. On the basis of original risk analysis methods, firstly, the author gives flood forecast and flood control operation fuzzy integration risk analysis method which using triangle fuzzy number; then, according to the suppose that typical flood processes selection is the added risk fator for classified forecast dispatching mode relatives to forecast dispatching mode, combining with example, typical flood processes selection risk has been analyzed, further the risk of designing and implementing classified forecast dispatching mode can be known.Lastly, the conclusions and the problems need to be further studied are given at the end of the dissertation.