Water Distribution Networks Resilience Analysis: a Comparison between Graph Theory-Based Approaches and Global Resilience Analysis

The structure and connectivity of infrastructure systems such as water distribution networks (WDNs) affect their reliability, efficiency and resilience. Suitable techniques are required to understand the potential impacts of system failure(s), which can result from internal (e.g. water hammer) or external (e.g. natural hazards) threats. This paper aims to compare two such techniques: Graph Theory (GT) and Global Resilience Analysis (GRA). These are applied to a real network – L’Aquila (central Italy) – and two benchmark networks – D-Town and EXNET. GT-based metrics focus on the topology of WDNs, while GRA provides a performance-based measure of a system’s resilience to a given system failure mode. Both methods provide information on the response of WDNs to pipe failure, but have different data requirements and thus different computational costs and precision. The results show that although GT measures provide considerable insight with respect to global WDN behavior and characteristics, performance-based analyses such as GRA (which provide detailed information on supply failure duration and magnitude) are crucial to better understand the local response of WDNs to pipe failure. Indeed, particularly for complex networks, topological characteristics may not be fully representative of hydraulic performances and pipe failure impacts.