Hydraulic Uniformity Index for Water Distribution Networks

Abstract

Various reliability measures have been developed to evaluate design and operational aspects of water distribution system (WDS) performance. Conventional reliability indicators mainly focus on nodal supply conditions, such as nodal pressure and available discharge. Here, a new link-based reliability index is proposed that considers pipe head loss–distribution throughout a network. The proposed index, the hydraulic uniformity index (HUI), is approximated using the equivalent hydraulic gradient and intends to distribute the hydraulic gradient as uniformly as possible throughout the network by enlarging steep-gradient pipes and reducing the size of low-gradient pipes, while satisfying the design constraints. The HUI is intended to overcome the shortcomings of conventional node-based indices by synchronizing the evaluation components with the design elements for intuitive system evaluation. An applied study using the Hanoi benchmark network demonstrates that the proposed HUI can be used as an indicator to evaluate system design and operational reliability.