Modeled Changes in Foredune Morphology Influenced by Storm Intensity, Sea-level Rise, and Mitigation Strategies
Date Thesis Awarded
Honors Thesis -- Access Restricted On-Campus Only
Bachelors of Science (BS)
Coastal foredunes can mitigate the impacts of hurricanes and extratropical storms on vulnerable, low-lying communities. However, the degree of foredune resilience to climatic changes remains largely unquantified. Here, we use AeoLiS, a numerical model that simulates sediment transport in supply limited conditions. We first project annual-scale patterns of accretion and erosion within coastal foredunes for a range of beach and dune morphologies representative of those along the Outer Banks, North Carolina, USA. The model is subsequently used to explore how sea-level rise and changes in storminess may modify future dune volumes across beach morphologies. Model outcomes suggest that even modest rates of sea-level rise may greatly exacerbate dune erosion. In contrast, increased storminess may either lead to dune accretion, due to increased wind speeds, or exacerbate erosion due to increased total water levels. The precise nature of these future impacts on coupled dune-beach systems is highly dependent on how climate change and the pre-existing beach morphology. Maintenance of the protective benefits of foredunes with increased sea-level and storminess will require management implementation such as vegetation plantings, sand fences and beach nourishment. To test vegetation planting mitigation capabilities against elevated coastal hazards, we also varied the plant coverage within the model domain to reflect the distribution observed within the Outer Banks. Model runs indicate dune vegetation can mitigate impacts of future environmental forcings, though spatial distribution can change dune accretion patterns. We found that climate change is unlikely to impact coastal foredunes uniformly, posing a challenge for communities relying on these features for protective services into the future in the context of both increasing sea level and changing storm properties.
Heminway, Selwyn, "Modeled Changes in Foredune Morphology Influenced by Storm Intensity, Sea-level Rise, and Mitigation Strategies" (2023). Undergraduate Honors Theses. William & Mary. Paper 2026.
Available for download on Friday, May 12, 2028
On-Campus Access Only