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| Titel |
High resolution numerical wave propagation in coastal area : benefits in assessment of the marine submersion |
| VerfasserIn |
Jean-François Dorville, Claude Cayol, Philippe Palany |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250133506
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| Publikation (Nr.) |
 EGU/EGU2016-14121.pdf |
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| Zusammenfassung |
| Many numerical models based on equation of action conservation (N = E∕σ) enables the
simulation of sea states (WAM, WW3,...). They allow through parametric equations to define
sources and sinks of wave energy (E(f,σ)) in spectral form. Statistics of the sea states
can be predicted at medium or long term as the significant wave height, the wave
pic direction, mean wave period, etc. Those predictions are better if initials and
boundaries conditions together with 10m wind field are well defined. Basically the more
homogeneous the marine area bathymetry is the more accurate the prediction will
be.
Météo-France for French West Indies and French Guiana (MF-DIRAG) is in
charge of the safety of persons and goods tries to improve knowledge and capacity to
evaluate the sea state at the coast and the marine submersion height using among
other statistical methods (as return periods) and numerical simulations. The area of
responsibility is large and includes different territory, type of coast and sea wave
climate.
Up today most part of the daily simulations were done for large areas and with
large meshes (10km). The needs of more accurate values in the assessment of
the marine submersion pushed to develop new strategies to estimate the level of
the sea water on the coast line and therefore characterize the marine submersion
hazard.
Since 2013 new data are available to enhance the capacity to simulate the mechanical
process at the coast. High resolution DEM Litto 3D for Guadeloupe and Martinique coasts
with grid-spacing of 5m up to 5km of the coast are free of use.
The study presents the methodology applied at MF-DIRAG in study mode to evaluate
effects of wave breaking on coastline. The method is based on wave simulation downscaling
form the Atlantic basin to the coastal area using MF-WAM to an sub kilometric
unstructured WW3 or SWAN depending to the domain studied. At the final step a
non-hydrostatic wave flow as SWASH is used on the coast completed by an analytical method
based on Stockdon et al. 2006 to validate the water level estimation. The water
circulation due to storm surge and tide is at this point computed separately with an
oceanic model including a coastal configuration and only used as an input in the wave
models.
The method is testing on two documented hurricane events (Dean 2007 and Omar 2008),
results, accuracy and computation cost are presented. A special attention is brought to wave
breaking simulation on coast of small to medium slope. |
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