Optimal Location Of Water Quality Monitoring Stations In Water Distribution System In Mountain City

It has been shown that with the rapid development of society and economy,it is more and more important to ensure the water quality safety.Previous research has shown that water quality monitoring stations set at key nodes could effectively monitor the dynamic changes of water quality,which was of great significance for ensuring water supply security.This study is one of the contents of"Research and Demonstration of Key Technologies for Urban Water Supply Security in the Three Gorges Reservoir Area"(Project No.2017YFC0404706).The urban water supply network was taken as the research object in this study,its water supply characteristics was analyzed and water quality model was constructed,and the optimal arrangement technology of water quality monitoring stations which can be applied to mountainous cities is put forward,which provides scientific basis and experience for the optimization arrangement of water quality monitoring stations in mountainous cities.The main research results and conclusions are as follows:Firstly,the software of EPANET 2.0 is used to build the network topology,and then a dynamic model of pipe network hydraulic and water quality is established.Through the model,the flow velocity and the water flow time of each pipe can be obtained,and the contamination events also can be simulated,which provides data support for the optimization model of water quality monitoring stations to detect contamination events.Secondly,it is set up that a mathematical model of conventional water quality monitoring stations (?).This model overcomes the disadvantage of traditional water quality monitoring stations model based on coverage method.The weight of node water quality and the node age constraint are increased,compared to the original model.The genetic algorithm and Intlinprog function are proposed to solve the model.Next,the optimal site selection of water quality monitoring stations warning against contamination is studied.Two different calculation methods are proposed.The first one is a simple heuristic method based on the concept‘construction of shortest travel time trees'to achieve targeted level of service(LOS),which can detect 100%of the contamination under a certain monitoring level without large computational work.It is given that two kinds of multi-objective mixed integer programming model max(?).Combined with the example pipe network,the reasonable monitoring position in water distribution systems is screened by the NSGA-II algorithm with the objective of detection likehood(DL)and time of detection(TD).The program can detect contamination events as quickly as possible.Finally,the emphasis is put on the optimization of water quality monitoring sites in mountainous cities based on the supply of pipe network zoning.The concept of"node risk level"is put forward,which is applied as a weighted value to the improved mathematical model of optimizing water quality monitoring stations.The idea of streamlining the topological structure of the pipe network and establishing a simple water quality model are also outlined,which can effectively solve the complicated water quality model of the water supply network in mountainous cities.The application of methodology is extended to engineering examples,the optimal arrangement of water quality monitoring stations in this area is established to effectively increase the water quality safety of the pipe network in this area,providing ideas and experiences for the arrangement of water quality monitoring stations in similar cities.