Author(s): Angelos Alamanos; Suzanne Linnane; Triona Mcgrath

Linked Author(s): Angelos Alamanos

Keywords: Resilience; Water supply; Systems theory; Hazards; Drinking water systems

Abstract: Drinking water supply systems today are facing multiple challenges, forced by extreme phenomena or conditions that act as disturbances to the provision of water services: changing climate can stress water systems, increase the severity of both droughts and floods, while urbanization and population growth can increase the water demand (overall, seasonally, spatially alternation). Furthermore, water quality and disposal issues, infrastructure condition (aging, damages, misconnections) and poor management and monitoring can make it difficult to diagnose the exact problems and their location. Other challenges include the recent Covid-19’s effects regarding water demand increase for hygiene and possible alterations of pressures patterns; and other threats such as earthquakes, hurricanes, or tides that can negatively affect the systems’ performance and the provided services. Studying urban water supply in the context of System Theory has provided certain advantages in addressing the above challenges, including the exploration, understanding and optimization of the problem’s boundary conditions, its causal-effect relations, and testing its behaviour as a system of various interconnected structural and non-structural elements. The ultimate goal of studying such systems is to improve their performance, and make them resilient. The international literature has provided several interpretations of the term resilience, which translate into different quantification measures and metrics. This research sums the different definitions and mathematical representations of resilience for drinking water supply systems: Approaches based on recovery, necessary systems’ properties for resistance to supply and demand stresses, engineering resilience, ecological resilience, time-dependent status changes, magnitude of disturbance metrics (hazard–based definitions), adaptability, transformability, key performance thresholds, etc. are reviewed. The different methodologies, resilience focuses, and tools are also presented and assessed. The aim is to categorize them, for the first time to our knowledge in such a way, to facilitate their study. The resulted categories include failure followed by functional state, duration of unsatisfactory versus functional states, coverage of services (ability to supply, access, maintaining water service), dynamic representation of the system’s performance, recovery-related resilience, and functions of other features or indicators, etc. Through the analysis, this work provides a useful guide to academics, analysts and practitioners for selecting the most appropriate approach depending on the studied problem, the external threat(s), and the data availability.

DOI: https://doi.org/10.3850/IAHR-39WC252171192022893

Year: 2022