Research On Reservoir Operation Considering Uncertain Factors

The research of reservoir operations has two main con tents:the identification of hydrological processes and the study of dispatching methods,the two are progressive relations,the former serves the latter.However,the hydrological process itself is an uncertain process,plus other uncertain factors such as the method in the research process,which will ultimately affect the results of the reservoir in actual operation.Both flood control and water supply are the goals of reservoir operation,to better achieve these two goals,many uncertain factors in reservoir planning and design to operation need to be overcome,this paper studies this issue.For the flood control operation of the reservoir,taking the Ankang Reservoir on the upper reaches of the Han River as an example,the design flood considering the joint distribution of linear uncertainty and flood peak flood volume was first deduced,and the limiting risk rate of the reservoir under the design flood uncertainty and its influencing factors were calculated and analyzed;secondly,constructing the optimal flood control dispatch model of Ankang Reservoir,solving the dispatching rules,and analyzing the safety of the related flood control design.For the research of water supply operation,the Dongzhuang Reservoir,which undertakes the task of water supply,is taken as the research object to analyze the uncertain water supply and demand process,and the optimal water supply scheduling model of Dongzhuang Reservoir is constructed based on the input conditions,and the scheduling rules solved by the model are derived and analyzed.The main research contents and results of this article are as follows:(1)The improved Bayesian model synthesis method is used to derive the edge distribution probability density function of the extreme value sequence of flood peak flood volume considering linear uncertainty,and on the basis of this,the joint distribution model of flood peak flood volume is constructed by Copula function,and Ankang is deduced Joint design flood of two reservoir variables.The results show that the flood peak design value of the two-variable joint design flood considering the linear uncertainty in Ankang Reservoir is larger than the origin al design value under the same recurrence period;while the flood volume design value is greater than the original design value during the low recurrence period.The high recurrence period is smaller than the original design value.(2)Based on the calculation results and theoretical methods of the two-variable joint design flood,the limit risk rate and its influencing factors of different prevention and control indicators of Ankang Reservoir were calculated and analyzed,and the stochastic dynamic programming model for optimal flood control operation of Ankang Reservoir was established,and the scheduling rules were solved,and the safety of related flood control design has been analyzed.The results show that:the short-fat type and the floods with late flood peak time are more unfavorable for the flood control of Ankang Reservoir.Taking into account the joint distribution of peak volume and the current flood control scheduling rules of Ankang Reservoir,the limit risk rate corresponding to the design flood level and normal storage level of Ankang Reservoir are 0.24%and 1.69%respectively.Ankang Reservoir is relatively sensitive to the flood flow during the swell period during the flood control operation.which is limited by the discharge capacity.The original flood control index once in a hundred years may be destroyed.(3)Using the marginal distribution model combined with the joint distribution model based on Copula function,the probability matrix of runoff transfer and probability matrix of runoff water demand of Dongzhuang Reservoir were deduced respectively.Using this as the input condition,the Dongzhuang Reservoir was established with the minimum water shortage as the target's stochastic dynamic programming model,solve the model and draw the optimal water supply operation schedule of Dongzhuang Reservoir.The results show that the SDP-D model rules which take into account the uncertainty of the water supply and demand process and their internal relations perform best.When the average water shortage for many years is reduced by 13 millon m3 compared to when there is no reservoir adjustment,the guarantee rate of water supply has also increased by 5%,and its water supply process also meets the principle of storage and supplement.The model method can greatly improve the water resources utilization efficiency of the reservoir and provide a reference for the formulation of water supply reservoir rules.