Study On Water Quantity And Quality Dispatching Model Of Urban River Network In Tidal Areas

With the rapid development of Fuzhou's economy,the water ecology of Fuzhou's main urban area is seriously damaged,and the phenomenon of black and odorous water is becoming more and more common.To solve the problem of urban water environment,it is urgent to study the movement law of urban river network water flow and the change of water environment.This paper takes the river network of the Jiangbei urban area in Fuzhou as the object.Based on the hydrological factor observation,the mathematical model of the one-dimensional water quality and water quality is established by using the characteristics of the river network,the water ecology and the water environment.Based on the model construction,the model was validated and verified by two field measured water level flow data in August 2012 and October 2012.The results show that the constructed hydrodynamic water quality coupling model can be better.It reflects the regularity of the distribution of water flow and pollutant movement under the control of the current working conditions,and meets the actual needs of this study.NH3 was selected as an important indicator to investigate water quality,and the established coupling model was used to simulate the inland river water supply project and the “improvement project”(planning ecological water supply project)in Jiangbei urban area under 50%,60%,70% and 80% interception rate conditions.Under the circumstances of hydrodynamic water quality,research and analysis of the characteristics of the temporal and spatial changes of river water quality,identify the problems of inland river hydrodynamic water quality,and carry out research on the joint dispatching scheme of inland river gate pump for the main problems.According to the research of joint scheduling of gate pump,the SCE-UA algorithm is used to optimize the control parameters of hydraulic structures,and the optimization model based on SCE-UA is constructed to simulate the two optimized scenarios.The optimal scheduling scheme is optimized to achieve reasonable results.The goal of allocating water and improving the quality of inland waters.The main conclusions of this paper are as follows:(1)Using the proven hydrodynamic water quality model to simulate the current water supply project,the results show that under the current conditions,the water diversion of Xinxihe Pumping Station has obvious influence on the water quality of Baima River water system.Among them,the variation of Daqing River water quality The most severe;the Guangming Port water system in the Meizhou River,a river in Guangming Port and other rivers affected by the closure of the riverside sluice,resulting in poor water quality;Jin'an River system in the middle of Pingtung River-Wusi River-Qiongdong River area and Qiongdong Due to the unreasonable distribution of water diversion flow in the river-Tiegang port area,the eastern Moyanghe River system,the Xindian film system and the Jinan River tributary have different water quality problems due to lack of water supply.(2)Using the constructed model to simulate the “perfect project”,the results show that under the “perfect working conditions”,the water quality improvement effect of the Baima River system and the Guangminggang water system is close to the current status project;the improvement effect of the Jin'an River water system is reduced.Among them,Pingtung River and Tiegang Port have the most outstanding water quality problems;the water quality in the upper reaches of the Moyang River is good,but the water quality in the lower reaches of the Moyang River has not improved significantly;the water quality of the Xindian film system has been improved due to sufficient hydration.(3)On the basis of “perfect engineering”,carry out optimization research,use SCE-UA algorithm to solve the parameters of hydraulic model of optimization model,simulate the two optimization schemes based on improved model,and investigate two optimization schemes.Improvement of water quality.The results show that the improvement effect of the two schemes is equivalent,and the water quality of the inland rivers in Jiangbei can reach the surface V water standard.However,for the iron port channel,by comparing the peak of the NH3 index,the improvement effect of the optimization scheme 2 is 2.6 times that of the first scheme and 4.5 times that of the “perfect project”.In addition,considering the economic,environmental protection and safety factors of building the sluice,it is concluded that the second option is better than the first one.Through the research in this paper,the water quantity and water quality coupling model simulation and small area joint dispatching results carried out in the river network of Jiangbei urban area have good adaptability and reliability,and provide water environmental protection and treatment for Fuzhou and cities with similar river system characteristics.Theoretical basis and technical support.