Seismic Performance Assessment of Water Distribution Systems Based on Multi-Indexed Nodal Importance

Abstract

Seismic performance assessment of water distribution systems (WDSs) based on hydraulic simulation is essential for resilience evaluation of WDSs under earthquake disasters. The assessment is mainly to determine how the water supply will be affected due to pipe breaks caused by the earthquake, with the water supply loss estimated based on the loss of supply to nodes. Existing research works usually use the average or overall performance metric of all user nodes as the system performance indicator without considering user nodes’ individual performance and criticality. This paper proposes a framework to evaluate the importance of user nodes considering post-earthquake rescue service and the seismic performance of individual user nodes in the WDS, which supports the pipeline renovation plan to improve the performance of critical user nodes. The importance of user nodes is evaluated by a multi-index model, including the indices for daily service, post-earthquake rescue service, and network topology influence of user nodes. These indices evaluate the importance of user nodes in terms of their roles for daily water service, emergent rescue service, and water transmission to other nodes, respectively. Fragility model of pipelines evaluates the earthquake-induced damages of the WDS, and the seismic performance assessment of the WDS system is performed by the hydraulic model of the WDS with pipeline damages. The proposed framework is implemented in an actual WDS; the results show that the importance classification to user nodes by multi-index approach can identify the critical user nodes for post-earthquake rescue service, which traditional methods may ignore. The importance classification and seismic performance of individual user nodes make it feasible to check the seismic performance of critical user nodes and formulate a targeted pipeline renovation plan to focus limited resources on critical user nodes.

Resilience of Interdependent Urban Water Systems

“…(3) Lack of (consumption) data during critical events: Although the simulation of failure scenarios is the basis for resilience assessment and intervention planning, the creation of the scenarios is usually a customized process. For example, failure scenarios created following traditional concepts for water distribution systems do not consider demand relocations under critical events, as indicated in [17,18]. The reason mainly lies in the lack of systematic studies on the behaviors of urban water systems under failure states due to the high uncertainties.…”

“…Resilience assessment in water distribution systems requires measuring the systems' performance under many failure scenarios [2,5,16]. However, current methods simulate the failure scenarios by imposing stresses on the system (e.g., pipe failure) without considering any possible changes of other attributes in the system during the failure, e.g., relocation of water demands caused by moving people to evacuation shelters during a critical event, such as bomb disposals, that require evacuations or natural catastrophes [17,18]. Given the importance of emergency planning in critical events, a deeper understanding of the systems' changes in the events is crucial for more accurate and comprehensive resilience evaluation, which will avoid misleading emergency solutions.…”

“…Hou, Ma, Diao, Zhong and Wu [17] analyzed the relocation of water demands in water distribution systems under earthquake disasters and found that during post-earthquake rescue and restoration, the water demands at user nodes may change significantly from those of daily service under normal conditions. For example, household and commercial water demands will reduce dramatically or even disappear, while water demands for post-earthquake rescue will increase tremendously, which is also more urgent than the others.…”

“…For example, household and commercial water demands will reduce dramatically or even disappear, while water demands for post-earthquake rescue will increase tremendously, which is also more urgent than the others. Based on these understandings, Hou, Ma, Diao, Zhong and Wu [17] developed a multi-index framework to assess the criticality of individual user nodes in terms of their roles for daily life service, emergent rescue service, and water transmission to other nodes, respectively. This multi-index measure can identify critical nodes for post-earthquake rescue service, which may be ignored by single importance index approaches.…”

Optimizing gas pipeline routing considering seismic risk through metaheuristic algorithm

“…Pipeline seismic vulnerability is typically determined using empirical relationships that correlate with various earthquake intensities at different levels (Mina et al, 2020). The repair rate (RR) is a quantitative indicator to determine the vulnerability of pipelines due to earthquakes (Hou et al, 2021). Managing and mitigating these vulnerabilities is crucial for ensuring the safety and reliability of pipelines in earthquake-prone regions.…”