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Two-dimensional time dependent hurricane overwash and erosion modeling at Santa Rosa Island

Coastal Engineering

By:
, , , , , ,
DOI: 10.1016/j.coastaleng.2010.02.006

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Abstract

A 2DH numerical, model which is capable of computing nearshore circulation and morphodynamics, including dune erosion, breaching and overwash, is used to simulate overwash caused by Hurricane Ivan (2004) on a barrier island. The model is forced using parametric wave and surge time series based on field data and large-scale numerical model results. The model predicted beach face and dune erosion reasonably well as well as the development of washover fans. Furthermore, the model demonstrated considerable quantitative skill (upwards of 66% of variance explained, maximum bias - 0.21 m) in hindcasting the post-storm shape and elevation of the subaerial barrier island when a sheet flow sediment transport limiter was applied. The prediction skill ranged between 0.66 and 0.77 in a series of sensitivity tests in which several hydraulic forcing parameters were varied. The sensitivity studies showed that the variations in the incident wave height and wave period affected the entire simulated island morphology while variations in the surge level gradient between the ocean and back barrier bay affected the amount of deposition on the back barrier and in the back barrier bay. The model sensitivity to the sheet flow sediment transport limiter, which served as a proxy for unknown factors controlling the resistance to erosion, was significantly greater than the sensitivity to the hydraulic forcing parameters. If no limiter was applied the simulated morphological response of the barrier island was an order of magnitude greater than the measured morphological response.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Two-dimensional time dependent hurricane overwash and erosion modeling at Santa Rosa Island
Series title:
Coastal Engineering
DOI:
10.1016/j.coastaleng.2010.02.006
Volume
57
Issue:
7
Year Published:
2010
Language:
English
Publisher:
Elsevier
Publisher location:
Amsterdam, Netherlands
Contributing office(s):
St. Petersburg Coastal and Marine Science Center
Description:
16 p.
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
First page:
668
Last page:
683