Rate of Post-Hurricane Barrier Island Recovery

• Main Author: Hammond, Brianna
• Other Authors: Houser, Chris, Bishop, Michael, Giardino, Rick
• Format: Thesis
• Language: English
• Published: 2015
• Subjects: barrier island; coastal geomorphology; hurricane recovery; Barrier Island; Low Island
• Online Access: https://hdl.handle.net/1969.1/155435

Barrier island foredunes are key indicators of the rate of island transgression, in which small dunes exhibit rapid transgression through washover and breaching, and large dunes exhibit controlled transgression in response to sea level rise. Recent evidence suggests that the largest foredunes at Santa Rosa Island, Florida and Galveston Island, Texas exhibit sigmoidal recovery patterns over an approximately 10 year time period, and that high and low islands vary alongshore in a pattern that is reinforced if there is a sufficient recovery period. This study examines the resiliency of Assateague Island National Seashore, MD through its ability to return to its pre-storm condition following a hurricane. The primary hypothesis of this study is that the rate of recovery of each examined parameter at ASIS will exhibit a sigmoidal pattern as seen at Santa Rosa Island, and that recovery rates will vary alongshore due to high and low island areas. Foredune elevation data from 2000 and 2005 was compared and categorized into recovery periods based on the temporal difference between impactful storm surges and the 2005 elevation data. Morphometric parameters including dune crest, height, volume, and toe were extracted and used to characterize recovery. Logistic curves were modified to represent the growth patterns of each parameter and recovery was examined with respect to high and low island sections. The rates of recovery from this study were compared with the results of a previous at Santa Rosa Island, FL. Results from this study support recovery patterns identified in previous studies. Evidence also suggests that low dunes at Assateague Island cease to recover and that there is a limit to the growth of the smallest dunes. Land managers can use this knowledge as a resource in the preparation for and response to hurricanes, specifically as it relates to varying levels of vulnerability alongshore.