Nodal vulnerability assessment of water distribution networks: An integrated Fuzzy AHP-TOPSIS approach

Abstract

Water Distribution Networks (WDNs) ensure reliable water supply to consumers which depends largely on joint and well-coordinated functioning of all diverse facets and components of the WDN. Failure of a vital component has catastrophic consequences and could impair the overall performance of the distribution system. This study presents an integrated Fuzzy AHP-TOPSIS framework that couples selected topological, hydraulic and water quality parameters to holistically assess nodal vulnerability of WDNs even under conflicting priority ranking of the methods considered. Within this framework, we harmonize the unique strengths of Closeness Centrality, Demand Adjusted Closeness Centrality and a Water Quality Index to accurately characterize the vulnerability of demand nodes. The proposed framework is validated on two case studies. The results indicate the ability of the integrated framework to accurately rank demand nodes, differentiate between nodes with the same base demand and distinguish between sink nodes based on water quality. The vulnerability indexes presented by the framework cannot be exhaustively explained by any of the original methods, an indication that the integrated framework provides new information in vulnerability analysis of WDNs. The framework could serve as a tool for water engineers in the analysis of critical nodes, scheduling of maintenance strategies and the assessment of failure impact on water distribution networks.