INTERCONNECTIVITIES BETWEEN HAZARD, DAMAGE, AND SHORELINE TYPE: LESSONS LEARNED FROM HURRICANE IRMA’S IMPACT ON THE FLORIDA KEYS

Abstract

The 2017 Atlantic hurricane season had 17 named storms, 10 hurricanes, and 6 major hurricanes, generating over 226 units of accumulated cyclone energy (ACE), a measure used by the National Oceanographic and Atmospheric Association (NOAA) that refers to the combined the intensity and duration of a hurricane. These statistics earned the hurricane season’s classification as “extremely active,” the most active since 2005. Preliminary estimates of damage due to Hurricanes Harvey, Irma, and Maria amount to over $200 billion dollars in the United States alone. Recent studies suggest that the frequency of these high intensity Category 4 and 5 hurricanes is increasing (e.g. Mendelsohn et al., 2012). The 2017 hurricane season may thus be representative of an expected season. Accounting for projected increases in mean sea level, storm impacts may be exacerbated in coastal regions. These trends emphasize the need for effective damage mitigation techniques that improve the robustness and resiliency of coastal communities. Structures must be designed to not only avoid wave and surge loads, but also resist these forces in the event of a wave impact. Furthermore, creative, cost-effective solutions are required to mitigate waves and surge before they reach developed coastal areas. Thus, engineers require a robust, science-based methodology for predicting details of wave propagation over land and inland effects to ensure life safety and reduce economic loss due to extreme events. While traditional engineering strategies (e.g. seawalls, bulkheads) have been used to prevent coastal erosion and mitigate inland effects of hurricane waves and surge, recent storm events have shown potential of nature and natural based features (e.g. dune vegetation, mangroves, wetlands, salt-marshes, coral reefs, and seagrass) to protect coastal structures during storm events.