Systemic vulnerability assessment of urban water distribution networks considering failure scenario uncertainty

Water distribution networks (WDNs) are vital infrastructures in cities. However, reports about urban WDNs incidents that result in major system breakdowns and water outages are not uncommon, which repeatedly highlights the urgency of addressing vulnerability challenges of WDNs. This study aims to propose a new method for system-level, scenario independent vulnerability assessment of WDNs, which considers the uncertainty in various failures that may happen in the system. The proposed method is developed based on the notion that the vulnerability of WDN is largely determined by its heterogeneity in node importance, which impacts how likely system malfunction or breakdown would happen should a small amount of nodes be attacked. Accordingly, the proposed method uses a set of indicators to measure the functional, structural and overall importance of each node in WDN, and introduces a novel network entropy model to measure the heterogeneity of importance of these nodes. The proposed method then assesses the systemic vulnerability of WDN, by benchmarking its current entropy against the entropies associated with the least and most vulnerable states of the system. The efficacy of the proposed method is demonstrated in a case study, in which the assessment yielded by the proposed method was found theoretically reasonable as well as consistent with actual conditions of the case WDN. (C) 2019 Elsevier B.V. All rights reserved.