Coastal Flood Risk in a Changing Climate along the Northern Gulf of Mexico

Coastal regions around the world are experiencing increased vulnerability from natural and manmade disasters. It is anticipated that coastal flood risk will increase due to the effects of climate change, and sea level rise (SLR) in particular. A dynamic, physics-based, framework to compute coastal flood inundation maps under various climate change scenarios was developed. The novel modeling system includes not only SLR, but considers future projections of shoreline evolution and primary dune morphology, upland migration of intertidal marsh, and land use land cover change. A present day hurricane storm surge model was generated for the Mississippi, Alabama, and Florida panhandle coasts. The model was shown to agree with measured data for astronomic tides and hurricane storm surge (Hurricanes Ivan, Dennis, Katrina, and Isaac) for present day conditions. The present day model was then modified to portray the potential outlook of the coastal landscape under climate change scenarios coupled to SLR scenarios. Shoreline profiles were modified (including the primary dune) and intertidal regions were permitted to migrate upland considering coastal infrastructure from impending migration. Bottom friction and hurricane wind reduction parameters were altered as informed from land use land cover projections. The various model configurations representing the future coastal landscape were forced by a suite of historical and synthetic tropical cyclones and flood maximum flood depths and inundation extents are computed. The collection of results allow the development of flood risk maps for varying scenarios of SLR and highlight the vulnerability of the coast to potential future climate change conditions