Document Type

Thesis

Abstract

Accurate prediction of beach response to storms requires synthesizing complex relationships among nearshore hydrodynamics, underlying geology, nearshore bathymetry, beach topography, and sediment characteristics. Previous research on the Outer Banks of North Carolina has correlated the presence of underlying paleo-channels, nearshore heterogeneous sediment, and shore-oblique bars with shoreline erosional hotspots and undulations in the shape of the shoreline (megacusps and embayments on the scale of 1000m). Despite the documented relationships among these features, the morphodynamic link between the persistent nearshore bathymetry, shoreline morphology, and long-term erosion is unknown. This study quantifies the spatial and temporal variations between foreshore topography, slope, grain size, shoreline dissipation width, and maximum runup during an extra-tropical storm along the Kitty Hawk, NC erosional hotspot Analysis of topographic data suggests that during the storm the lower foreshore eroded and flattened and the upper foreshore accreted and steepened, with erosion focused on the megacusp horns and embayments. No obvious alongshore patterns exist in mean grain size, and foreshore slope and mean grain size were not related during or after the storm. Foreshore slope, swash dissipation width, and maximum runup were not related after the storm, which suggests that common expected parameter relationships are not applicable in this region of irregular surf zone bathymetry. Results from this study suggest that other parameters, such as alongshore variations in wave setup, should be included in calculations of maximum runup for models of alongshore variability in shoreline erosion in response to storm events.

Date Awarded

2009

Department

Geology

Advisor 1

Jesse E. McNinch

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