Application of A Two-Dimensional (Monetary-Mortality) Flood Risk Assessment Approach in Evaluation of Coastal Flood Risk Reduction

Abstract:

In 1986, the US Water Resources Development Act required that loss of human life associated with coastal storm events shall be displayed in the Benefit-Cost Analysis of planning. However, coastal storm risk reduction decision-making for the United States is presently still only quantifying monetary risk reduction benefits but not mortality risk. Here, a two-dimensional (2D) flood risk assessment incorporating mortality with monetary damage is applied to examine the potential effect on adaptation evaluation. Jamaica Bay, New York, is a heavily urbanized coastal area with high vulnerability to coastal flooding and storm surge, amplified by rising sea levels. We use a case study of Jamaica Bay to evaluate the hypothesis that flood risk reduction benefit analyses quantifying mortality risk reduction lead to different rankings of adaptations than those quantifying monetary risk reduction. The hypothesis is tested by simulating flood scenarios with sea level rise and potential risk reduction plans using hydrodynamic modeling, and assessing monetary damage and mortality using predictive consequence models. Adaptation evaluation based on the 2D flood risk assessment consisting of mortality and monetary risk has the advantage of taking a wider range of negative consequences into consideration. Alongside a specific Corps of Engineers feasibility study, we provide an example of how mortality risk can be considered as a metric apart from monetary damage in flood risk reduction decision-making.