Emergency threshold index: a way to measure and map community resilience to climate change
The ubiquitous concept of resilience has opened new perspectives also in the field of Disaster Risk Reduction (DRR) and Climate Change Adaptation (CCA), and is fostering inclusive approaches, such as the social-ecological one, engrossed in the adaptive capacity of a system to adjust to a specific environment. In such an approach, the availability and use of resources becomes pivotal in differentiating structural (hard) and functional (soft) resilience; to lower vulnerability to a system must define the optimum equilibrium between these two components. Obviously, the choice of hard or soft measures to reduce climate change vulnerability and risk depends on economic, cultural and strategic choices. A major hurdle in applying the concept of resilience to DRR and CCA is the effective assessment of a system’s resilience, namely the capacity of the community as a whole to prepare for, respond to, and recover from adverse events. Decisive in this computation is the definition of which parameters and factors influence the emergency threshold of a system. Such threshold, dependent on intrinsic characteristics of the system and its surrounding environment, establishes the limit beyond which the system will lose stability. From a qualitative standpoint, it exemplifies the ratio between the magnitude of impact (e.g. tropical cyclones or drought) and the resources available to the social-ecological system. Quantifying this threshold into an index will help choosing the most appropriate CCA actions. Moreover, an Emergency Thresholds Index will help move from the classic view of a map of risk to a map of territorial resilience.