General resilience addresses the resilience of a water system to any threat including
unknowns, in contrast to specified resilience to individual identified threats. However,
quantification of general resilience is challenging and previous assessments have typically
been qualitative or based on system properties that are assumed ...
General resilience addresses the resilience of a water system to any threat including
unknowns, in contrast to specified resilience to individual identified threats. However,
quantification of general resilience is challenging and previous assessments have typically
been qualitative or based on system properties that are assumed to be indicative of resilient
performance. Here we present a General Resilience Assessment Methodology (GRAM),
which uses a middle-state based approach to decompose general resilience into contributing
components to provide a quantitative and performance-based resilience assessment. GRAM
enables the accounting of the effects of any threat if all modes of system failure are
identifiable. It is applied to an integrated urban wastewater system where five interventions
are explored. The results obtained show that whilst substantial improvements in specified
resilience are achieved, increasing the general resilience of the system is challenging.
However, general resilience analysis enables identification of system failure modes to which
level of service is least resilient and highlights key opportunities for intervention
development. GRAM is beneficial as it can inform the development of interventions to
increase the resilience of a system to unknowns such as unforeseeable natural hazards in a
quantifiable manner.