Evaluation of Sustainability Index of Water Distribution Network Using Demand-Driven and Pressure-Driven Analysis

This study presents a sustainability analysis of optimally designed water distribution networks (WDNs) under hydraulic failure situations using demand-driven analysis (DDA) and pressure-driven analysis (PDA). Two benchmark WDNs and their discrete designs are considered for this purpose. Hydraulic uncertain conditions are generated as a simultaneous variation of nodal demands and roughness coefficient using Monte Carlo simulation considering two different coefficient of variation (COV) values. The nodal performance of these networks is estimated using average nodal reliability (ANR) and average nodal vulnerability (ANV) metrics. The hydraulically efficient and critical nodes are ascertained from these measures, which are essential for proper operations and maintenance. Apart, the system performance measures, such as average system reliability (ASR), average system resilience (ASRes), and average system vulnerability (ASV), are evaluated. Since, all these performance measures resulted in different conclusions, an aggregate performance measure, the sustainability index (SI), is considered. Unlike other studies, the SI of WDN under uncertain scenarios and subsequently the average sustainability index (ASI) is measured. The evaluation of ASI that quantifies the network's sustainability is intuitive and helps to select a better design from a set of optimal designs with similar costs and different diameter sets. Further, the study compares DDA and PDA analysis, demonstrating no-flow, full, and partial-flow situations. The statistical variation of the results is also illustrated. DDA underestimated the network hydraulics, which became faultier with the increase in uncertainty. The underestimation of hydraulic parameters misleads design, operational, and maintenance decision making. Thus, the study suggests PDA as the most reliable model for performance analysis and the optimal design of WDNs.

Automated summary

This study conducts a sustainability analysis of water distribution networks under hydraulic failure situations using demand-driven analysis (DDA) and pressure-driven analysis (PDA). The study evaluates the network performance under uncertain conditions and proposes a sustainability index (SI) as an aggregate performance measure. It compares DDA and PDA analysis and concludes that PDA is the most reliable model for performance analysis and optimal design of water distribution networks.