Preliminary Assessment of Transport Trends in a Transgressive Barrier Island Chain Using Multidimensional Numerical Models

Increased tropical cyclone frequency in the past decade has resulted in an increased rate of landward migration, transgressive submergence, and dynamic changes in barrier island areal extent. Field observations in the summer of 2007 and 2008, and historical data including satellite and aerial reconnaissance flights in the vicinity and offshore of the barrier chain were used to assess the destructive and constructive processes during intermediate and high energy events, as well as low energy conditions during the recovery period. A multidimensional numerical modeling approach is undertaken here to quantitatively and qualitatively estimate transport trends across the islands, and better determine the future recovery modes of the islands. Long-term wind and wave climate using 25 years of observations from nearby (offshore) buoys were used to assess the dominant transport pathways for different periods during the year. Two and three-dimensional hydrodynamic, wave and sediment transport models were also used to investigate changes in the dominant transport trends during high and low energy conditions, and how this might affect the islands ability to maintain its aerial footprint during high storm activity.