From lab to landscape-scale experiments for the morphodynamics of sand dunes
We review the main processes that drive the morphodynamics of dunes, i.e. their growth in height, migration and elongation, and emphasise the contribution of experiments to the understanding of these mechanisms. The main control parameters are the sediment flux Q and the saturation length $L_{\mathr...
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| Format: | Article |
| Language: | English |
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Académie des sciences
2024-11-01
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| Series: | Comptes Rendus. Physique |
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| Online Access: | https://comptes-rendus.academie-sciences.fr/physique/articles/10.5802/crphys.203/ |
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| author | Claudin, Philippe Courrech du Pont, Sylvain Narteau, Clément |
| author_facet | Claudin, Philippe Courrech du Pont, Sylvain Narteau, Clément |
| author_sort | Claudin, Philippe |
| collection | DOAJ |
| description | We review the main processes that drive the morphodynamics of dunes, i.e. their growth in height, migration and elongation, and emphasise the contribution of experiments to the understanding of these mechanisms. The main control parameters are the sediment flux Q and the saturation length $L_{\mathrm{sat}}$ associated with the spatial relaxation of the flux towards the transport capacity. The other relevant quantities are essentially dimensionless: fluid response to a bed perturbation, dune geometry (orientation, aspect ratio), transport ratios under multi-directional wind regimes. We argue that laboratory experiments dealing with sedimentary bedforms in water flows are good analogues to study the morphodynamics of aeolian dunes at reduced length and time scales, as $L_{\mathrm{sat}}$ and $L_{\mathrm{sat}}^2/Q$ are expected to be smaller for subaqueous bedload. Besides, dune shape and dynamics are mainly governed by flow and boundary conditions, independent of the transport mode. We discuss different experimental set-ups and results, especially concerning dune pattern orientation and dune interaction. Under natural wind regimes in terrestrial deserts, we show the potential of field experiments in which the control of initial and boundary conditions allows for the quantification of all the relevant mechanisms involved in dune growth. We emphasise the general agreement between observations, measurements and theoretical predictions, which indicates a robust comprehension of the underlying processes. This understanding can serve as a foundation for further investigations, including the interpretation of dune landscapes and the resolution of inverse problems. |
| format | Article |
| id | doaj-art-2f757d9739324c718af57f6e8fccd5c7 |
| institution | Kabale University |
| issn | 1878-1535 |
| language | English |
| publishDate | 2024-11-01 |
| publisher | Académie des sciences |
| record_format | Article |
| series | Comptes Rendus. Physique |
| spelling | doaj-art-2f757d9739324c718af57f6e8fccd5c72025-02-07T13:54:24ZengAcadémie des sciencesComptes Rendus. Physique1878-15352024-11-0112910.5802/crphys.20310.5802/crphys.203From lab to landscape-scale experiments for the morphodynamics of sand dunesClaudin, Philippe0https://orcid.org/0000-0001-8975-4500Courrech du Pont, Sylvain1Narteau, Clément2https://orcid.org/0000-0002-9556-9544Physique et Mécanique des Milieux Hétérogènes, CNRS – ESPCI – PSL Research Univ. – Sorbonne Univ. – Univ. Paris Cité, Paris, FranceLaboratoire Matière et Systèmes Complexes, Univ. Paris Cité, CNRS, Paris, FranceInstitut de Physique du Globe de Paris, Univ. Paris Cité, CNRS, Paris, FranceWe review the main processes that drive the morphodynamics of dunes, i.e. their growth in height, migration and elongation, and emphasise the contribution of experiments to the understanding of these mechanisms. The main control parameters are the sediment flux Q and the saturation length $L_{\mathrm{sat}}$ associated with the spatial relaxation of the flux towards the transport capacity. The other relevant quantities are essentially dimensionless: fluid response to a bed perturbation, dune geometry (orientation, aspect ratio), transport ratios under multi-directional wind regimes. We argue that laboratory experiments dealing with sedimentary bedforms in water flows are good analogues to study the morphodynamics of aeolian dunes at reduced length and time scales, as $L_{\mathrm{sat}}$ and $L_{\mathrm{sat}}^2/Q$ are expected to be smaller for subaqueous bedload. Besides, dune shape and dynamics are mainly governed by flow and boundary conditions, independent of the transport mode. We discuss different experimental set-ups and results, especially concerning dune pattern orientation and dune interaction. Under natural wind regimes in terrestrial deserts, we show the potential of field experiments in which the control of initial and boundary conditions allows for the quantification of all the relevant mechanisms involved in dune growth. We emphasise the general agreement between observations, measurements and theoretical predictions, which indicates a robust comprehension of the underlying processes. This understanding can serve as a foundation for further investigations, including the interpretation of dune landscapes and the resolution of inverse problems.https://comptes-rendus.academie-sciences.fr/physique/articles/10.5802/crphys.203/dune shape and dynamicsgrowthorientation |
| spellingShingle | Claudin, Philippe Courrech du Pont, Sylvain Narteau, Clément From lab to landscape-scale experiments for the morphodynamics of sand dunes Comptes Rendus. Physique dune shape and dynamics growth orientation |
| title | From lab to landscape-scale experiments for the morphodynamics of sand dunes |
| title_full | From lab to landscape-scale experiments for the morphodynamics of sand dunes |
| title_fullStr | From lab to landscape-scale experiments for the morphodynamics of sand dunes |
| title_full_unstemmed | From lab to landscape-scale experiments for the morphodynamics of sand dunes |
| title_short | From lab to landscape-scale experiments for the morphodynamics of sand dunes |
| title_sort | from lab to landscape scale experiments for the morphodynamics of sand dunes |
| topic | dune shape and dynamics growth orientation |
| url | https://comptes-rendus.academie-sciences.fr/physique/articles/10.5802/crphys.203/ |
| work_keys_str_mv | AT claudinphilippe fromlabtolandscapescaleexperimentsforthemorphodynamicsofsanddunes AT courrechdupontsylvain fromlabtolandscapescaleexperimentsforthemorphodynamicsofsanddunes AT narteauclement fromlabtolandscapescaleexperimentsforthemorphodynamicsofsanddunes |