Defense Date
2026
Document Type
Dissertation
Degree Name
Doctor of Philosophy
Department
Mathematical Sciences
First Advisor
David M. Chan
Second Advisor
H. Reed Ogrosky
Abstract
Barrier islands are critical for coastal communities, as they serve as a natural buffer against storm surge, waves, and the effects of rising sea levels, protecting life and property. These islands continuously evolve due to both normal and severe environmental conditions; global warming makes it increasingly difficult to predict the evolution of these islands due to increases in storm frequency and intensity. We present a cellular model of barrier island evolution consisting of biotic and abiotic processes including the effects of vegetation, wind, ocean currents, and gravity. The model is used to predict the future evolution of barrier islands off the coast of Virginia. Three future overwash scenarios are considered: one influenced by historical overwash trends, one considering increased overwash frequency, and one considering both increased overwash frequency and intensity. The model predicts that disturbance-reinforcing regions--- regions with little woody vegetation and low elevation--- exhibit more landward migration than disturbance-resisting regions with higher vegetation and topographic complexity. This study highlights the significance of biogeomorphic interactions for the evolution of barrier islands and can aid future predictions due to the uncertain effects of global warming.
Additionally, the model is used to create a metric of island resistance that predicts short-term island evolution and can be used to bring an increased understanding to scientists, policy makers, and the general public. The development of a metric is extremely pertinent as global warming increases the rate at which these islands evolve through increased storm activity, erosion, and rising sea-levels. There are several examples of multifunctional scales that are used to warn the general public of expected events, such as the Saffir-Simpson hurricane wind scale and the air-quality index. The proposed metric is more complex, as it is composed of multiple island components. The metric results emphasize the importance of woody vegetation and topographic complexity for a more resistant island as well as highlight the dynamic nature of island evolution in response to intense storms or recovery periods.
Rights
© The Author
Is Part Of
VCU University Archives
Is Part Of
VCU Theses and Dissertations
Date of Submission
5-7-2026