Changes in sediment transport processes at the Chandeleur Islands, Louisiana in response to storm impact

We analyzed elevation changes at the northern Chandeleur Islands, Louisiana, to quantify sediment fluxes and assess sediment transport processes over two time periods (1920 – 2007 and 2007 – 2015). Wave-driven alongshore sediment transport is the predominant fair-weather process, whereas storms transport sediment across the island platform and promote shoreline retreat. Major storm impacts, where storm surge exceeds island elevation, severely erode the island platform and remove sediment from the system. During periods of recovery, onshore bar migration and welding contribute to subaerial island growth. The analyses show changes in dominant transport processes type and dominance relative to storm response over the two time periods. These results provide understanding on the sediment transport processes that drive the geomorphic evolution of barrier islands which is crucial for predicting future resilience.