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| Titel |
Ground water response under infragravity wave forcing on the beach face |
| VerfasserIn |
Olivier David de Drezigue, Damien Sous, Adrien Lambert, Vincent Rey |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250045230
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| Zusammenfassung |
| As a part of the ECORS program (financial support SHOM, France), which
is a qualification campaign for sandy beach morphodynamic models, an
instrumental field study has been conducted on the Truc Vert beach in
Aquitaine, France. The main objective of this study was to characterize
surf and swash zones dynamics of a barred macro-tidal beach. A
particular attention was paid to infragravity energy and groundwater
dynamics, and their impact on sediment transport.
A dedicated instrumentation has been deployed to cover a cross-section
of the beach from the berm to the intertidal lowest point. It consists
in a line of single pressure sensors and velocimeters alternatively
immersed and emerged during the tide cycle. In addition, several steel
bars (up to 2.5 meters high) supporting 2 or 3 pressure sensors have
been buried in the sand in order to combine vertical and horizontal
characterization of the water surface for each side of foreshore
surface.
Analysis is focused on the transformations of short and long waves in
the near shore and their transmission to the groundwater. Thanks to
spectral analyses of pressure data, a predominent infragravity energy is
observed in the inner surf zone and in the swash zone. This energy,
which is supposed to play a significant role in the sediment transport
processes, is transferred toward the watertable through pressure wave
propagation in the saturated zone and in the capillarity frange. |
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