Centre for Water Systems, University of Exeter, North Park Rd, Exeter, EX4 4QF, UK; Faculty of Technology, De Montfort University, Mill Lane, Leicester, LE2 7DR, UK.
Centre for Water Systems, University of Exeter, North Park Rd, Exeter, EX4 4QF, UK.
Water Res. 2016 Dec 1;106:383-393. doi: 10.1016/j.watres.2016.10.011. Epub 2016 Oct 4.
Evaluating and enhancing resilience in water infrastructure is a crucial step towards more sustainable urban water management. As a prerequisite to enhancing resilience, a detailed understanding is required of the inherent resilience of the underlying system. Differing from traditional risk analysis, here we propose a global resilience analysis (GRA) approach that shifts the objective from analysing multiple and unknown threats to analysing the more identifiable and measurable system responses to extreme conditions, i.e. potential failure modes. GRA aims to evaluate a system's resilience to a possible failure mode regardless of the causal threat(s) (known or unknown, external or internal). The method is applied to test the resilience of four water distribution systems (WDSs) with various features to three typical failure modes (pipe failure, excess demand, and substance intrusion). The study reveals GRA provides an overview of a water system's resilience to various failure modes. For each failure mode, it identifies the range of corresponding failure impacts and reveals extreme scenarios (e.g. the complete loss of water supply with only 5% pipe failure, or still meeting 80% of demand despite over 70% of pipes failing). GRA also reveals that increased resilience to one failure mode may decrease resilience to another and increasing system capacity may delay the system's recovery in some situations. It is also shown that selecting an appropriate level of detail for hydraulic models is of great importance in resilience analysis. The method can be used as a comprehensive diagnostic framework to evaluate a range of interventions for improving system resilience in future studies.
评估和增强水基础设施的弹性是实现更可持续的城市水资源管理的关键步骤。作为增强弹性的前提条件，需要深入了解基础系统的固有弹性。与传统的风险分析不同，我们在这里提出了一种全局弹性分析（GRA）方法，该方法将目标从分析多个未知威胁转变为分析更可识别和可测量的系统对极端条件的响应，即潜在的失效模式。GRA 的目的是评估系统对可能失效模式的弹性，而不考虑潜在的威胁（已知或未知、外部或内部）。该方法应用于测试具有不同特征的四个配水系统（WDS）对三种典型失效模式（管道失效、需求过剩和物质入侵）的弹性。研究表明，GRA 提供了对各种失效模式下的水系统弹性的概述。对于每种失效模式，它确定了相应失效影响的范围，并揭示了极端情况（例如，仅 5%的管道失效就会导致供水完全中断，或者尽管 70%以上的管道失效，但仍能满足 80%的需求）。GRA 还表明，对一种失效模式的弹性增加可能会降低对另一种失效模式的弹性，并且增加系统容量在某些情况下可能会延迟系统的恢复。还表明，在弹性分析中选择适当的水力模型细节水平非常重要。该方法可用作综合诊断框架，用于评估未来研究中提高系统弹性的一系列干预措施。
