Interaction of Barrier Islands and Storms: Implications for Flood Risk Reduction in Louisiana and Mississippi

Coastal barrier islands are natural lines of defense and an integral part of a comprehensive flood risk reduction and management plan. A high resolution numerical modeling system capable of representing complicated coastal landscapes and simulating all the primary relevant physical processes is applied to better understand the influence of barrier island restoration on hurricane surge propagation. Model results indicate that barrier island restoration may significantly alter surge pathways and flood volumes of surge reaching inland coastal areas as open water passes become the dominant flow mechanism during a storm event. However, the exclusion of the morphologic evolution of a barrier island during a storm's passage is a significant limitation with the existing numerical models and is currently under development. The results in this paper demonstrate the need to include morphologic changes to fully evaluate the impact barrier islands have on water levels at the mainland coast.