• Building national earthquake resilience should foster synergies between resilience to earthquakes and to other hazards.
• Communities should consider developing multi-tier resilience goals and strategies, i.e., different performance expectations for different scale events. In some cases, it may be effective to focus actions on containing the effects of “expected” events, rather than very rare, “extreme” events.
• Resilience involves both pre-disaster mitigation (activities to reduce the amount of loss in an event) and the ability to mute post-event losses and rapidly recover from an event.
• Resilience should allow for systemic change, especially in low-probability, high-consequence events. Resilience does not necessarily entail a return to “normal” or “pre-disaster” conditions. Reducing future risk should also be a goal of recovery activities.
With these considerations in mind, the committee recommends that NEHRP adopt the following working definition for “national earthquake resilience” (applicable more generally to all-hazards resilience):
A disaster-resilient nation is one in which its communities, through mitigation and pre-disaster preparation, develop the adaptive capacity to maintain important community functions and recover quickly when major disasters occur.
Reflecting the lack of a consensus definition, no standard metric exists for measuring disaster resilience. Indeed, one of the priorities in the National Science and Technology Council’s (NSTC’s) Grand Challenges for Disaster Reduction is to “assess disaster resilience using standard methods” (SDR, 2005; p. 2). As this report noted, such metrics are needed for several reasons: “With consistent factors and regularly updated metrics, communities will be able to maintain report cards that accurately assess the community’s level of disaster resilience. This, in turn, will support comparability among communities and provide a context for action to further reduce vulnerability. Validated models, standards, and metrics are needed for estimating cumulative losses, projecting the impact of changes in technology and policies, and monitoring the overall estimated economic loss avoidance of planned actions” (SDR, 2005; p. 2). Perhaps most importantly, standardized methods are needed to gauge improvements in resilience as a result of disaster risk reduction planning and mitigation.
Metrics of disaster resilience differ from the familiar metrics of disaster risk in several ways. Standard risk measures include expected casualties, property damage, and business interruption loss—that is, estimates of