Resilience Assessment in Urban Water Infrastructure: A Critical Review of Approaches, Strategies and Applications

Urban water infrastructure (UWI), comprising the main systems including water supply systems (WSS), urban drainage/stormwater systems (UDS), and wastewater systems (WWS). The UWI need to be resilient to a wide range of shocks and stresses including structural failures such as pipe breakage and pump breakdown and functional failures such as unmet water demand/quality, flooding and combined sewer overflows. However, there is no general consensus about resilience assessment of these systems widely presented by various research works. This study aims to critically review the approaches, strategies and applications of the resilience assessment for the complex systems in UWI. This review includes examining bibliometric analysis, developed frameworks related to resilience assessment to help comprehend resilience concepts for the specified UWI systems in urban settings, strategies for improving resilience, resilience indicators and the common tools used for modelling resilience assessment in UWI. The results indicate that resilience assessment has primarily been conducted in developed countries, underscoring the macroeconomic significance of UWI. Three key areas have been identified for analysing resilience in UWI: system design, development of resilience concepts, and implementation of green infra-structure. Moreover, it has been discovered that although resilience is commonly defined using technical approaches, a more comprehensive understanding of resilience can be gained through a holistic approach. Furthermore, while strategies such as system upgrade, decentralisation, digi-talisation, and nature-based solutions can enhance the UWI resilience, they may be insufficient to fulfil all resilience indicators. To address the challenge of effectively comparing different resilience options, it is crucial to extensively examine comprehensive and sustainability-based indicators in future research