Integrating Decision Analysis with Fuzzy Programming: Application in Urban Water Distribution System Operation

Water-distribution operation is an essential part of an urban water-supply system to deliver high-quality water to consumers. Management of such an operation may involve deliberations of operation cost, system capacity, and environmental restriction, and is convoluted with many forms of uncertainties. In this paper, an integrated fuzzy programming and decision analysis (IFPDA) approach was proposed for a multilayer urban water-distribution system management under uncertainty. The system consisted of two water sources, four treatment plants, seven reservoirs, and seven consuming zones. Uncertain information associated with water demands, water-treatment capacities, water-transfer cost, and leakage rate was described by a trapezoidal-shaped fuzzy set and embedded into a fuzzy programming framework. The balance between the satisfaction degree of achieving the system objective and feasibility level of meeting the related constraints was analyzed by fuzzy inference procedures. The results indicate that the IFPDA approach was advantageous in (1)dealing with fuzzy uncertainties in the objective function, both sides of the model constraints, and the context of an urban water-distribution system management; (2)helping analyze tradeoffs between minimization of operation cost and reliability of running the system; and (3)linking optimization model outputs with decision analysis.