Study On Several Critical Problems Of Joint Operation And Allocation Of Multiple Water Sources In Beijing Based On Water Supply Of South Water Conveyed To North

With south-to-north water transfer project diverting water into Beijing,an integrated water supply system consisting of diverted water,local surface water and ground water establishes.Multi-water resources ensure the water supply security of Beijing,while on the other side,the joint water allocation problem among Multi-water resources,the waterworks and storage system is urgent to dealing on practical applications.This research focuses on the problems of water supply system water of Beijing City,studies on the multi source water rc(?)urces variation,water encountered problems and risk management,water demand prediction,joint water operation of different calculation scales and emergency conditions,and obtaines the following main results:(1)Study on the rules of water resources of Beijing water supply system.A variety of research indexes and methods were choosed to analyze the runoff variation in Danjiangkou reservoir and Miyun Reservoir.Results showed that intraannual runoff changed severely and interannual runoff distributed enevenly.The periodic properties of runoff changed obviously and water quantity showed a decreasing treend.(2)According to the global climate model GCM,choosing RCP4.5 emission scenarios,statistical downscaling method was applied to predict future precipitation of Danjiangkou reservoir and Miyun Reservoir and SPI drought index was selected to analysze the future drought conditions.Results showed that,in the future precipitation of the two regional decrease SPI changes unevenly with extreme drought events frequent occurring.(3)Combined with the function of Copula and the Bayesian network,we constructed a risk analysis model of two water resources.Results showed that the probability of the most unfavorable water diversion scenarios(Danjiangkou reservoir dry years suffered the Miyun Reservoir in dry year)is 27.56%,water transfer favorable probability is 72.44%.(4)The construction of node graph on water allocation and analysis of the impact of storage capacity of Daning reservoir to the multi-circle water supplying system are done.By the application of PSO to calculate the model about the minimum shortage water,we obtain the most appropriate storage capacity of Daning reservoir under the scenario of unforecasted and forescated water of south-north water diversion project,which are 779 and 498.56 ten thousand m3(5)Since the South-North Water Diversion Project was implemented,the function of Miyun reservoir contains the adjustment of water allocation,and also the reserve water source of Beijing city.Hence,we propose the index on water exchange rate,build the water allocation model of the maximum index and solving the model by the application of MOPSO(6)Considering the diverted water is 0,Miyun reservoir inflow is 0,link network emergencies and extreme operating conditions,establishing water dispatching rules,computing the water system scheme on different accidents,we get water distribution loop results under emergency situation.