Scheduling of water distribution systems using A multiobjective approach
Ordonnancement des systèmes de distribution d'eau en utilisant une approche multi-objectif
Résumé
Water utilities ensure the delivery of water to population with the help of networks and plants, which allow transport and treatment of water from the source to the end users. We focus on the distribution of water from the storage area to the consumers. Historically, the major part of European water networks was laid after the Second World War until the beginning of 1980 years. The priority of water utilities are changing. The goal is not only to deliver water to users, but to enhance the reliability of the network by reducing the occurrence of leaks and failures, in order to improve the service level. Thus, many utilities are dealing with problems relative to water quality, leaks, loss of pressure in pipes, interruptions of water distribution and contamination of water. Those problems can be described by factors dealing with the state of the pipes itself and the environment that brings deterioration. So, water utilities have to prevent occurrence of failures and lack of water by an adequate renewal policy. The objective of our work is to propose a decision tool taking into account technical and economical criteria. We have to identify which pipes should be considered? Which rehabilitation should be done? When it should be done? How much would it cost? In which manner the water utility would dispose of su.cient resources to support works on the network? How the budget is planned? We consider in decision making: the entire networks by measuring impact of a decision at the scale of a pipe on the entire network, the hydraulic deterioration of the network, qualitative variables in decision making, assessing and allocating budget to rehabilitation according to a multiobjective approach.