An optimal design strategy of decentralized storage tank locations for multi-objective control of initial rainwater quality

In recent years, frequent non-point source pollution has raised serious challenges for urban water environmental management. The efficiency and cost of water quality storage tanks, which can prevent and control urban pollution effectively, are significantly affected by their locations. However, few studies have determined the location of decentralized storage tanks with consideration of the characteristics of initial rainwater quality, which has led to unsatisfactory or extravagant design. Therefore, a new design strategy is proposed to optimize the locations of water quality storage tanks using the InfoWorks ICM model in this study. It includes two basic steps. Firstly, the pollution severity of each node in the corresponding subcatchment is evaluated and ranked through the matter element analysis method and analytic hierarchy process. Secondly, all the nodes are precisely sorted by their excessive multiples using the single factor index method. Its application in the design of the decentralized storage tank locations in Fuzhou, China, proved that the proposed strategy can reduce the total volume of decentralized storage tanks to 0.38 times that of a terminal tank. The strategy presented in this study may also be useful in other research on storage tank design in urban pollution prevention and control systems.