An Integrated Modeling and Data Analysis Approach to Understanding Louisiana's Wetland Resilience to Hurricane Landfall

The northern Gulf of Mexico, with its unique bathymetric, geometric, and landscape features, is extremely susceptible to the impacts of frequent tropical storms and hurricanes. Tropical cyclones have caused severe coastal flooding, enormous damage to properties and loss of lives in this region, as seen in the devastation of recent hurricanes, including Hurricanes Katrina and Rita in 2005, and Gustav and Ike in 2008. Louisiana wetland loss, already occurring at an alarming rate, is accelerated in landfall events, although sedimentation may also benefit some regions. One approach to combatting wetland loss are river diversions which reduce salinity; certain diversions also provide river sediment. However, their contribution to surge and wave reduction is controversial. Overall, our present understanding of coastal wetland resiliency from hurricane impacts is rather inadequate.

This research seeks to improve our understanding of coastal resiliency from hurricane impacts using integrated numerical modeling, in-situ observations and remote sensing techniques. We will present a dataset analysis of wetland changes based on Landsat 5 data during hurricane events in the Breton Sound region. It will be shown that the erosion is disproportionately high in the vicinity of the Caernarvon diversion, originally designed to enhance marsh regrowth (as well as reduce salinity). Apparently, the new freshwater marsh near the diversion is not as resilient as saltwater marsh to hurricane events.

We will also show early results of a model coupling framework from storm surge, wave, and sediment models. The models will include a shallow-water version of WAVEWATCH III, the ADvanced CIRCulation model, and the HWRF model.