Deterioration and Optimal Rehabilitation Modelling for Urban Water Distribution Systems

This book presents a whole-life cost optimisation model for the rehabilitation of water distribution systems. The pipe breakage number prediction model combines the physical characteristics of the pipes with historical data on breakage and failure rates. The criticality assessment model combines a pipe’s condition with its hydraulic significance. The whole life cost optimal rehabilitation model is a multiple-objective and multiple-stage model to minimise the whole life cost while maximising long-term performance of the system. The utility of the models is that it allows decision makers to prioritize their rehabilitation strategy in a proactive and cost-effective manner.

Pipe failures in water distribution systems can have a serious impact and hence it’s important to maintain the condition and integrity of the distribution system. This book presents a whole-life cost optimisation model for the rehabilitation of water distribution systems. It combines a pipe breakage number prediction model with a pipe criticality assessment model, which enables the creation of a well-constructed and more tightly constrained optimisation model. The pipe breakage number prediction model combines information on the physical characteristics of the pipes with historical information on breakage and failure rates. A weighted multiple nonlinear regression analysis is applied to describe the condition of different pipe groups. The criticality assessment model combines a pipe’s condition with its hydraulic significance through a modified TOPSIS. This model enables the optimisation to focus its efforts on those important pipes. The whole life cost optimal rehabilitation model is a multiple-objective and multiple-stage model, which provides a suite of rehabilitation decisions that minimise the whole life cost while maximising its long-term performance. The optimisation model is solved using a modified NSGA-II. The utility of the developed models is that it allows decision makers to prioritize their rehabilitation strategy in a proactive and cost-effective manner.