Water quality based reliability analysis for water distribution networks

Abstract

The research work in the past two decades on reliability analysis of water distribution networks (WDNs) is primarily focused on assessing the reliability from the point of view of hydraulics, that is, supplying the required quantity of water at the desired pressure, using various qualitative and quantitative measures. A minimum desired level of residual chlorine at consumer's tap is needed to supply quality water. In this article, both the quality and quantity of water is taken into account to assess the reliability of a WDN using a ‘water quality reliability factor’. The water quality reliability factor is defined as the ratio of the total quantity of desired quality of water supplied by the network to the total quantity of desired quality of water required to be supplied in the period of analysis. Pipe-break and pump-failure conditions are considered as random events. Hydraulic simulation of network under pressure-deficient conditions resulting from pipe-break and pump-failure conditions is carried out using node flow analysis. The proposed methodology is illustrated with two example networks taken from the literature.

Keywords:

• reliability
• water distribution networks
• water networks
• water quality

Acknowledgements

The financial support received from the University Grants Commission for the research work is gratefully acknowledged.