Quantifying Barrier Island Recovery Following a Hurricane

Abstract:

Barrier islands are dynamic landscapes that are believed to minimize storm impact to mainland communities and also provide important ecological services in the coastal environment. The protection afforded by the island and the services it provides, however, depend on island resiliency in the face of accelerated sea level rise, which is in turn dependent on the rate of island recovery following storm events that may also change in both frequency and magnitude in the future. These changes in frequency may affect even large dunes and their resiliency, resulting in the island transitioning from a high to a low elevation. Previous research has shown that the condition of the foredune depends on the recovery of the nearshore and beach profile and the ability of vegetation to capture aeolian-transported sediment. An inability of the foredune to recover may result in mainland susceptibility to storm energy, inability for ecosystems to recover and thrive, and sediment budget instability. In this study, LiDAR data is used to quantify the rates of dune recovery at Fire Island, NY, the Outer Banks, NC, Santa Rosa Island, FL, and Matagorda Island, TX. Preliminary results indicate foredune recovery varies significantly both alongshore and in the cross-shore, suggesting that barrier island response and recovery to storm events cannot be considered from a strictly two-dimensional (cross-shore) perspective.