Flaw of demand coverage based method for optimal locations of monitoring stations and modification

The method of locating online sensor on a water distribution system for monitoring water quality was investigated.A flaw of demand coverage method was identified.To overcome this flaw,a demand coverage index based method was proposed in this paper.The demand coverage index method evaluates a node's representativeness by taking both the total amount of demand coverage and its temporal distribution into account.This increases the calculation accuracy and data representativeness.In order to increase the speed of optimization,a genetic algorithm was employed to solve the optimization problem in this work.Two example water distribution systems were employed to evaluate the performances of both methods.It was obtained that more than 85% of node demand can be covered by 7 monitoring stations for the example water distribution system with 95 nodes.Example applications show that results from this method have better representativeness than the one from demand coverage method.An online monitoring network based on optimal locations obtained from demand coverage method can better represent water quality of the distribution systems.