Study On Optimal Operation And Early Warning Of Multi-objective Water Supply In Jinxiuchuan Reservoir

Water is a source of life.For Jinan,“the City of Springs”,reasonable planning for the use of water resources not only guarantees urban water security,but also contributes to the replenishment of water source and the undertaking of springs protection.Jinxiuchuan Reservoir,an important water source in the mountain area of southern Jinan,is also a multi-purpose water conservancy project integrating flood control,irrigation,urban water supply,ecological water supplement,power generation,etc.In addition to the above water supply tasks,Jinxiuchuan Reservoir has also played the key role of providing ecological water supplement in the “five-reservoir connection” project established and carried out by Jinan.Based on the completed east route of the South-to-North Water Transfer Project,this project is to connect Jinxiuchuan Reservoir,Wohushan Reservoir,Xinglong Reservoir and two other reservoirs for water supply scheduling,as well as to enhance the utilization rate of water resources by combining foreign water and the supplement water.Along with soaring economy in the southern mountain area,both the natural and the social environment have gone through great changes.Meanwhile,the contradiction between supply and demand of water resources stood out.Hence,how to improve the technology of reservoir operation to realize reasonable allocation of water resources has become an urgent problem at the moment.This research took Jinxiuchuan Reservoir as the subject,and built two optimal scheduling model sets for the water supply task of Jinxiuchuan Reservoir in its routine work and the “five-reservoir connection” project respectively to discuss its role in regular scheduling,real-time scheduling and ecological scheduling.The main contents and results of the research are as follows:(1)The research ranked the frequency of the selected measured runoff data at Jinxiuchuan Reservoir over 33 years from 1984 to 2016,and ran the MK mutation detection.According to the results,the selected runoff series showed significant mutation in 1988~1989,indicating distinct peak-valley characteristics of runoff in this period,making it applicable for the regulation calculation of the schedule map.(2)The research improved the general schedule map compilation by the following.First,changing the direct use of long series to selected use of representative intervals;second,determining the reasonable initial water level and drawdown level that match with the calculation interval.On such a basis,the research selected 1985~1989 as the representative interval,and determined the initial water level(235m)for the lower risk(12.02%)scenario that is applicable to Jinxiuchuan Reservoir.An improved multi-objective reservoir scheduling map was then drawn using these parameters,and then the series flow data were substitutedinto this map in order to tailor the calculation.Subsequently,it was found that the water-supply guarantee rates in cases of irrigation,urban water supply and power generation all met the actual demands.The research further built a multi-objective optimal allocation model for irrigation,power generation,etc.,and generate the solutions with LINGO.The results obtained by substituting the same target year,initial water level and drawdown level as those for regular scheduling indicated that,the efficiencies of both water supply and power generation have been enhanced.(3)In the context of the “five-reservoir connection” project,this research built an optimization model under single-reservoir static constraints targeting the ecological water demands of the Jinxiuchuan Reservoir–Wohushan Reservoir ecological corridor.According to results obtained by substituting the data of a dry year(90%)into the model,Jinxiuchuan Reservoir could provide about 2.48 million cubic meters of ecological water per year to the ecological corridor on average in drier years,showing an effective water supply.Next,the research generated random water use programs with the Monte Carlo method,simulated the water supply with MIKE11,fitted the derived formula of flow rate and calculated the early-warning threshold according to the simulation,categorizing it into three early-warning levels(low,medium,high).After receiving early-warning signals,managers may make decisions on the amount of water to be released using the derived formula.