Reducing Risk and Increasing Resilience to High-Impact Events: Roles of the Weather, Water, and Climate Communities

In the weather, water, and climate enterprises emphasis is placed on understanding and improving risk and resilience to high-impact events, which may occur during severe weather outbreaks (weather enterprise), coastal, inland, and flash flooding (water enterprise), and long-term sea level rise (climate enterprise). As such, the desires are to reduce risk and enhance resiliency.

Risk is defined as a combination of factors. One is the probability of a particular hazard event. Probabilities are typically related to expected impacts and may be placed into the context of return periods, allowances, or amplification factors. The second is the exposure of infrastructure or social structures, and the third is the vulnerability of those structures to a particular hazard. Reducing risk requires reducing the probability of a high-impact event or reducing the consequences of the event (exposure and vulnerability).

Resilience is related to specific components of infrastructure or social structures that include diversity, redundancy, and recovery. Therefore, to enhance resilience requires increasing diversity to provide for alternative actions; increasing redundancy that allows for components of a system to compensate for each other, and provide for recovery to allow an infrastructure or social structure to return to its initial state.

While the weather, water, and climate communities are typically in position to take actions that directly reduce risk and increase resiliency, the communities provide the information on which key decision makers rely to make policy and take actions with the goals of reducing risk and increasing resiliency. Typically, in a risk-based approach information used by decision makers is based on past and current hazard characteristics, exposure, and vulnerabilities. Furthermore, extension into the future assumes a stationary background, which is unrealistic in face of changing infrastructure, social structures, and physical climate.

A primary role of the worldwide weather, water, and climate enterprises is to communicate information. That information is gathered from knowledge of the relevant physical systems and the many tools that provide current and future states at a variety of space and time scales. To be useful in a risk-based decision-making scenario that information must be presented in such a manner that identifies likelihood and impact, and also quantifies uncertainty. Additionally, communication must be in a format that directly addresses the critical factors considered in how risk and resilience are defined.

While the components of risk (hazard, exposure, and vulnerability) and resilience (diversity, redundancy, and recovery) vary greatly worldwide, the international weather, water, and climate communities must work as a whole to develop innovative measures that provide uniformly highly relevant, actionable, and quality information to decision makers for the purpose of reducing risk and resilience. In this presentation, the factors that comprise risk and resilience are analyzed in conjunction with means of providing risk-based decision factors that address key needs such as a changing background state and infrastructures.