The importance of local mean time in remote sensing for mapping megatidal zones
| Autor: | Jean-Paul Deroin, Masanobu Shimada |
|---|---|
| Rok vydání: | 2010 |
| Předmět: |
Cap Ferret
Global and Planetary Change Sun-synchronous orbit Elevation ALOS Intertidal zone Vegetation Geologic map Baie des Veys Local mean time Multispectral pattern recognition JERS Mont Saint-Michel bay General Earth and Planetary Sciences Sun-synchronous France Bay Tidal flat Geology Remote sensing |
| Zdroj: | Comptes Rendus Geoscience. 342:11-18 |
| ISSN: | 1631-0713 |
| DOI: | 10.1016/j.crte.2009.08.009 |
| Popis: | The local mean time is rarely debated in applied remote sensing, although it is a key parameter, especially for the geological mapping of coastal areas with high tidal ranges. French test sites are used to illustrate the role of this parameter. Depending from location and for an average time of acquisition of 11:00 UTC, the exposed tidal flat ranges from 55% (Baie des Veys), 80% (Mont Saint-Michel) to 100% (Cap-Ferret). Eight multisource satellite images were used in the Mont Saint-Michel Bay to draw the limit of the sea and evaluate the corresponding tidal flat's surfaces for various times of acquisition. The relation emphasizes some geometrical properties of the lower part of the intertidal zone. A NW–SE profile allows one to identify a distal part with a slope of 0.2% and a proximal part with a slope of only 0.06%. JERS 1-OPS and ALOS-AVNIR-2 data have been also compared to evaluate the progression of the halophytic vegetation, covering more than 6 km 2 between 1992 and 2007. From a methodological point of view, the ALOS-AVNIR-2 acquired on October 2007 is the first satellite data covering the Mont Saint-Michel Bay with a water elevation of only 2.56 m, i.e . a tidal flat free of water over 80% of its surface. |
| Databáze: | OpenAIRE |
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