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Vulnerability Assessment of Coral Reefs

By Supplemental Appropriations for Disaster Recovery Activities

Coral reefs and the shallow seafloor that surrounds them serve as a natural barrier during storms, reducing wave energy thus protecting coastal populations and infrastructure from flooding and erosion. Declining coral reef health has caused coral reef and seafloor erosion while sea level has continued to rise, reducing the effectiveness of reefs to serve as natural breakwater.

Coral reefs can substantially reduce coastal flooding and erosion by dissipating up to 97% of incident wave energy. Reefs function like low-crested breakwaters, with hydrodynamic behavior well characterized by coastal engineering models. Recently, a process-based, high-resolution, non-linear model of coastal protection benefits provided by corals reefs that mapped these natural defense benefits at a resolution relevant to management scales, and provided a framework to rigorously value the people and property protected by coral reefs under numerous current and future climates, was developed for all populated U.S. coral reef-lined coasts (Rigorously Valuing the Role of U.S. Coral Reefs in Coastal Hazard Risk Reduction).

Hurricane Irma skirted the Territory Puerto Rico on 7 September 2017 and then struck the State of Florida as a Category 4 hurricane on 10 September 2017. Hurricane Irma caused dozens of deaths and more than \$50 billion in damage, thus being the costliest storm in the history of the State of Florida. Ten days later, Hurricane Maria, the strongest weather system to impact Puerto Rico since Hurricane San Felipe II in 1928, made landfall on the south coast of Puerto Rico as a Category 4 hurricane on 20 September 2017. Hurricane Maria caused thousands of deaths, more than \$90 billion in damage, and the biggest electrical blackout in US history.

As part of the U.S. Federal government’s recovery and restoration efforts, we are assessing (1) how the hurricane-induced damage to the coral reefs increased the risk to coastal communities; (2) how coral reef restoration could reduce the hazard to, and increase the resiliency of, coastal communities; and (3) how future coral reef degradation could increase the risk to coastal communities.

 

 

Return to Storm-induced Coastal Hazard Assessment for Coral Reef Coasts