Assessing Mortality Risk from Forecast Flood Events in a Middle Income Country: The Case of Barbados

Hydrologic forecasting tools continue to improve, providing an enhanced ability to forecast future storm surge and inland flooding events. With these enhancements in the science and computational efficiency of hydrologic assessment comes a better ability to plan for health implications of these floods and in particular, the risk of mortality. We review the main determinants of flood mortality risk in a generic hazard/vulnerability/risk/risk management framework, where unmitigated risk of loss of life is a function of the number of people exposed to a hazard and the forecast water depth, and then apply on-the-ground vulnerability and emergency shelter capacity information to illustrate the potential cost-effectiveness of actions to improve advance flood notification time and extent, and/or enhance emergency shelter capacity, in a middle income country (Barbados). The analysis builds on a recent, state-of-the-art flood risk hazard assessment and building stock vulnerability assessment. Fatality risk is evaluated for various return periods for inland flood events, and compared to other sources of natural disaster risk on the island (i.e., seismic and coastal flooding risk). The welfare economic implications of avoiding mortal risk are assessed using a transferred value of statistical life (VSL), and compared to the costs of improving notification time and shelter capacity. In addition, broader economic implications for the overall island economy, including health sector capacity, are explored qualitatively. Key gaps in understanding are also reviewed, such as more comprehensively assessing morbidity outcomes, and priorities for a continuing research agenda are identified.