Barrier island vulnerability to breaching: a case study on Dauphin Island, Alabama

Mark Hansen; Asbury H. Sallenger

doi:10.1061/40926(239)157

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Barrier island vulnerability to breaching: a case study on Dauphin Island, Alabama

Mark Hansen·Asbury H. Sallenger

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Abstract

Breaching of barrier islands can adversely impact society by severing infrastructure, destroying private properties, and altering water quality in back bays and estuaries. This study provides a scheme that assesses the relative vulnerability of a barrier island to breach during storms. Dauphin Island, Alabama was selected for this study because it has a well documented history of island breaches and extensive geological and geomorphic data. To assess the vulnerability of the island, we defined several variables contributing to the risk of breaching: island geology, breaching history, and island topography and geomorphology. These variables were combined to form a breaching index (BI) value for cross island computational bins, each bin every 50 m in the alongshore direction. Results suggest the eastern section of Dauphin Island has the lowest risk of breaching with the remaining portion of the island having a moderate to high risk of breaching. Two reaches in the western section of the island were found to be particularly vulnerable due primarily to their minimal cross-sectional dimensions.

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Source-reported bounding extent: 30.199377° to 30.312412° latitude; -88.327384° to -88.051287° longitude. This indicates report coverage, not an exact sampling location. View area on OpenStreetMap.

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BibTeX RIS

Mark Hansen, Asbury H. Sallenger. 2012-04-26. Barrier island vulnerability to breaching: a case study on Dauphin Island, Alabama. https://doi.org/10.1061/40926(239)157

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