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A method for semi-automated objective quantification of linear bedforms from multi-scale digital elevation models

Auteur(s) et Affiliation(s)

CAZENAVE, P.W.
School of Ocean and Earth Science, National Oceanography Centre, Southampton, Royaume-Uni
DIX, J.K.
School of Ocean and Earth Science, National Oceanography Centre, Southampton, Royaume-Uni
LAMBKIN, D.O.
ABP Marine Environmental Research Ltd, Southampton, Royaume-Uni
MCNEILL, L.C.
School of Ocean and Earth Science, National Oceanography Centre, Southampton, Royaume-Uni


Description :
The AA. (i) adapt and extend extant techniques to provide a suite of semi-automatic tools which calculate crest orientation, wavelength, height, asymmetry direction and asymmetry ratios of bedforms, and then (ii) undertake sensitivity tests on synthetic data, increasingly complex seabeds and a very large-scale (39 000 km2) aeolian dune system. The automated results are compared with traditional, manually derived, measurements at each stage. This new approach successfully analyses different types of topographic data (from aeolian and marine environments) from a range of sources, with tens of millions of data points being processed in a semi-automated and objective manner within minutes rather than hours or days. The results show there is significant variability in all measurable parameters in what might otherwise be considered uniform bedform fields. For example, the dunes of the Rub' al Khali on the Arabian peninsula are shown to exhibit deviations in dimensions from global trends. Morphological and dune asymmetry analysis of the Rub' al Khali suggests parts of the sand sea may be adjusting to a changed wind regime from that during their formation 100 to 10 ka BP.


Type de document :
Article de périodique

Source :
Earth surface processes and landforms, issn : 0197-9337, 2013, vol. 38, n°. 3, p. 221-236, nombre de pages : 16, Références bibliographiques : 2 p.

Date :
2013

Editeur :
Pays édition : Royaume-Uni, Chichester, Wiley

Langue :
Anglais
Droits :
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