Application of multi objective optimization for managing urban drought security in the presence of population growth

Scheduling expansion problems have typically been formulated to find the timing and scale of predefined projects that minimize the total present worth cost. The high capital and environmental costs of major infrastructure options have stimulated interest in optimizing operational decisions such as conservation rules as a way of delaying or avoiding investment in major infrastructure. This paper demonstrates the benefit of jointly optimizing staged infrastructure and operational decisions to cope with growth in urban water demand. It also demonstrates social equity problems that may arise from minimizing total present worth costs. It develops a multi-objective formulation for the scheduling expansion problem which enables cost and equity to be traded-off.