DUNAMICS

Analyse et prédiction des dunes sous-marines

Ce projet a reçu un financement du programme de recherche et d'innovation Horizon 2020 de l'Union européenne dans le cadre de la convention de subvention Marie Skłodowska-Curie n° 101021848

Les enjeux de Dunamics en vidéo

Présentation du projet

Dunes and ripples are fascinating bedforms which have continuously attracted great attention from the scientific community since the seminal work of Bagnold (1941) on aeolian dunes in the Sahara. Recent findings from spatial agencies revealed the presence of analogous bedforms in other planetary environments as diverse as Mars, Venus, Titan, Pluton or comet 67P/Churyumov-Gerasimenko, where dunes are sculpted by sunset thermal winds (1). Dunes are ubiquitous in terrestrial subaqueous environments and share the same universal mechanism of generation as their extra-terrestrial and aeolian counterparts. Sand dunes pose a significant risk for offshore activities in coastal areas, especially with the growing development of renewable marine energy (2), and for navigation along the most frequented maritime routes like for instance in the North Sea, in the French-English Channel or the Elbe estuary (3). The presence of sand dunes leads to a significant increase of the flow resistance (4), which needs to be carefully described for predicting flow velocities and water levels in forecast models. Understanding dune evolution is therefore an important issue to accurately predict the flow circulation, sediment fluxes and bathymetric variations in sandy subaqueous environments. Although sand dunes represent a great scientific and operational interest, their evolution is still poorly understood due to their complex behaviour. During my years of experience as a research coastal engineer, I could measure the need for a better comprehension of sand dune dynamics, which is an important factor in supporting the European green transition in the marine environment.

Questions that still need to be addressed are: 1) which physical mechanisms lead to dune equilibrium under different types of hydrodynamic conditions? 2) What are dune dimensions at equilibrium and controlling parameters? 3) Can we develop a numerical model framework to forecast in situ dunes evolution?

Following up on my research experience in dune morphodynamics, and hypotheses that I have formulated in my PhD, my ambition during the Marie Curie project is to follow an ambitious methodology to solve fundamental issues on our understanding of submarine dunes and improve their predictability. Therefore, I propose to use a combination of innovative flume measurement techniques, advanced numerical modelling approaches, and the analysis of high resolution in situ multibeam echosounder data sets. In addition to its novel scientific contributions, DUNAMICS will further reinforce my experience in numerical modelling, marine geology, and laboratory work. I will receive expert guidance in optical and acoustical methods and flume measurement techniques at the water engineering laboratory, based at the University of Auckland (UoA). DUNAMICS has been designed from the ground up for my maximum benefit in terms of skill acquisition, new collaborations and scientific dissemination.

References 

1 Jia, P., Andreotti, B. and P. Claudin, Proceedings of the National Academy of Sciences, 114 (10), 2509-2514 (2017).

2 Barrie, J. V., and K. W. Conway, Continental Shelf Research, 83, 45-52, (2014).

3 Vantorre, M., E. Lataire, M. Candries, J. van Doorn, and D. van Heel, Fourth International Conference on Marine and River Dune Dynamics, 301-308, (2013).

4 Deigaard,R., and J. Fredsøe, Proceedings of the 20th Coastal Engineering Conference, 1047-1061, (1987).

5 Perillo, M. M., Best, J. L., et. al., Sedimentology, 61, 2063-2085, (2014).

6 Kennedy, J. F., Journal of Fluid Mechanics, 16, 521-544, (1963). Engelund, F., Journal of Fluid Mechanics, 42(2), 225-244, (1970).


Arnaud Doré, 2/1 Rata road, 0624,  Devonport, Auckland - New Zealand
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