Capacity reliability of water distribution networks and optimum rehabilitation decision making

Abstract

Deterioration in pipes contributes to uncertainty about the carrying capacity in water distribution networks. Capacity reliability, defined as the probability that the carrying capacity meets the flow demand, is investigated in this paper to aid in maintenance and rehabilitation decision making for water distribution networks. This paper describes the use of capacity reliability for networks with more than one demand node through finding the probability of a feasible flow given probability distributions of flow capacities in the pipes and fixed nodal demands. The solution procedure generates a set of inequalities that represents a necessary and sufficient condition for feasible flow. A solution procedure is proposed for evaluating the probability that all the inequalities are satisfied by (1) eliminating redundant inequalities and (2) determining bounds for the probability of feasible flow. A decision-making framework is developed that applies both the capacity reliability measure and the solution approach for maintenance and rehabilitation decision making.