Water Quality Based Multi-objective Optimal Design of Water Distribution Systems

Lost in Optimisation of Water Distribution Systems? A Literature Review of System Design

“…Indeed, study [78] reports a significant tradeoff between water quality objective based on disinfectant residual and the system capital costs (i.e., the best quality solutions correspond to higher costs and vice versa), and demonstrates the sensitivity of the obtained solutions to a disinfectant dosage rate. Interestingly, there was not tradeoff found between water quality objective based on water age and the cost.…”

“…However, the use of those variables as well as objectives seems to vary across studies with no general framework on how to model tanks available. As far as decision variables are concerned, they include tank locations [71,72,[96][97][98][99]120], tank volumes [16,53,93,96,98,99], minimum (and maximum) operational levels [93,96,98,99], tank heads [78], tank elevations [14], ratio between diameter and height [98], ratio between emergency volume and total volume [98]. Study [99] compared two approaches to model tanks in terms of operational levels, first of which calculates tank levels analytically during the network analysis, and second of which includes tank levels as independent variables.…”

“…Alternatively, water quality is included as a constraint to a single-objective model in a form of minimum (and maximum) disinfectant concentrations at the network nodes [87,143]. In the latter, water quality presents a sole objective, which is either water quality benefit (being maximised) [63,131], water quality deficiencies (being minimised) [92,97,144] or water quality reliability (being maximised) [78].…”

“…A multi-objective optimisation approach was possibly first applied in the late 1990s (Figure 1), maximising the network benefit on one hand and minimising the system cost (of network rehabilitation) on the other hand [63]. In studies of newly designed WDSs, in addition to the economic measure, the other objectives considered were the pressure deficit [30,62,[64][65][66][67] or excess [68,69] at network nodes, the penalty cost for violating the pressure constraint [70], greenhouse gas (GHG) emissions [71][72][73][74][75][76] or emission cost [77], water discolouration risk [68] and water quality [78]. A multiobjective optimisation approach is considered "very appealing for engineers as it provides a tool to investigate interesting trade-offs", for example, a marginal pressure deficit can be outweighed by a considerable cost reduction [67].…”

Informational Entropy: a Failure Tolerance and Reliability Surrogate for Water Distribution Networks

“…Evolutionary optimization algorithms that rely on simulation models are very popular in many disciplines including water resources (Mora-Melia et al 2015;Borah and Bhattacharjya 2016;Chang et al 2016;Masoumi et al 2016;Shokoohi et al 2016;Steffelbauer and FuchsHanusch 2016). Simulation models make the inclusion of multiple operating conditions in optimization models relatively straightforward.…”