Date of Award


Document Type


Degree Name



Civil, Coastal, and Environmental Engineering

Committee Chair

Stephanie Patch, Ph.D., P.E.


Adaptation strategies are used to reduce vulnerability in response to storms and sea-level rise (SLR). An adaptation tipping point for a barrier island is said to exist when an adaptation strategy fails. Previous studies have applied statistics to identify adaptation tipping points and construct adaptation pathways as a function of quantity of SLR. This study is focused on Alligator Lake and Oleander Pond on the barrier island Dauphin Island, AL; a site residents and community leaders identified as vulnerable to saltwater intrusion under future SLR conditions. Therefore, the purposes of this study are to numerically simulate impacts of a storm and SLR scenarios on a barrier island freshwater aquifer, evaluate the effectiveness of adaptation strategies to prevent seawater contamination via overtopping as sea levels rise, and develop an adaptation pathway for protecting the freshwater supply under future climate scenarios. XBeach was used to simulate morphological changes to the region near Alligator Lake and Oleander Pond with merged DEM and Lidar data. SLR scenarios (0.40 m, 0.53 m, 0.66 m, 0.75 m, 1.00 m, 1.26 m, and 1.93 m) were simulated with Hurricane Nate hydrodynamic conditions. Overtopping occurred at 1.26 m and 1.93 m of SLR. An adaptation pathway was created with four adaptation strategies and seven SLR scenarios.