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| Titel |
Sediment flux from linear dunes morphodynamics in the Ténéré desert (Niger) |
| VerfasserIn |
Antoine Lucas, Clement Narteau, Sebastien Rodriguez, Olivier Rozier, Yann Callot, Amandine Garcia, Sylvain Courrech du Pont |
| 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 |
250132839
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| Publikation (Nr.) |
 EGU/EGU2016-13383.pdf |
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| Zusammenfassung |
| Linear dune development under complex wind regimes is hindered by our limited
comprehension of the underlying mechanisms. Therefore, sand flux calculation in
remote areas relies mainly on the migration rate of barchans using remote-sensing
data.
Based on more than 50 years of aerial and satellite imagery over the Ténéré desert
(Niger), we were able to isolate and therefore show that the observed linear dunes in this area
elongate from topographic obstacles in the direction of the resultant sand flux with no lateral
migration. These elongating lee dunes are therefore ideal for quantifying the dune growth
from extension only.
Using photogrammetric techniques we calculated a sediment flux of 30m2/yr. We also
emphasized the development sequences from numerical simulations and show how
deposition downstream of low hills results in nucleation and development of bedforms that
can later break into barchans and ultimately lead to Segmentation and ejection of linear
dunes.
As consequences, similarly to the classical approach using the barchans migration rates
under unidirectional winds, we can now take advantage of the morphodynamics of linear
dunes experiencing complex wind regimes for sediment flux and wind conditions
assessment. |
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