Storm surge is an abnormal rise of the sea surface caused by atmospheric forcing, including the wind stress and atmospheric pressure associated with extra-tropical and tropical cyclones. Hurricanes and typhoons have a great impact on coastal regions, and can cause severe loss of lives and great damages. A systematic investigation of storm surge impact to the coasts of Louisiana and Texas, where the continental shelf reaches up to 200 km in width, is conducted
here using the hydrodynamics Finite-Volume Coastal Ocean Model, FVCOM (Chen et al., 2003). The model is applied to the northern Gulf of Mexico to simulate the storm surges caused by Hurricanes Rita (September 2005) and Ike (September 2008), and allows the resolution of the
flooding along the Louisiana and Texas coasts. Observations of inland flooding from USGS are
used to validate the model with satisfactory results. Various idealized scenarios are also
simulated using FVCOM, to gain insight into specific surge mechanisms. This study focuses on
the following topics: 1) The roles of shelf geometry and tides in a hurricane surge are explored in a set of experiments where the nonlinear interaction between tide and surge is investigated and found to be important, relative to the tidal amplitude; 2) The receding flow of Hurricane Ritas surge waters back to the Gulf of Mexico and the different dynamics that produce the remarkably different flooding (~0.5 days) and return (>7 days) periods are explained; 3) The effect of the often overlooked forward speed of a hurricane, which was found to have an unexpected and significant impact on coastal surges, in that faster storms produce higher coastal peak surges but smaller overall inland flooding (vice-versa for slower storms); and 4) The importance of
Galveston Bays barrier islands on the propagation of Hurricane Ikes surge, where results suggested that under a realistic erosion scenario for Bolivar Peninsulas, the bay is exposed to dangerously high water levels almost as much as if the Peninsula was leveled to about Mean Sea Level, underlining the non-linear nature of this bay-barrier system.
| Identifer | oai:union.ndltd.org:LSU/oai:etd.lsu.edu:etd-06302009-161650 |
| Date | 05 July 2009 |
| Creators | Rego, Joao Lima |
| Contributors | James Catallo, Chunyan Li, Clinton S. Willson, Jaye E. Cable, Dimitris E. Nikitopoulos |
| Publisher | LSU |
| Source Sets | Louisiana State University |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lsu.edu/docs/available/etd-06302009-161650/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached herein a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to LSU or its agents the non-exclusive license to archive and make accessible, under the conditions specified below and in appropriate University policies, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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