Modelling the contribution of wind waves to Cap Ferret's updrift erosion
Wind waves breaking at an angle with the shoreline force the drifting of littoral sediments, which is known for contributing to the formation and growth of barrier spits. Intriguingly, increased rates of longshore wave power have also been associated with the erosion of some barrier spits on the upd...
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Online Access: | https://oskar-bordeaux.fr/handle/20.500.12278/184690 https://hdl.handle.net/20.500.12278/184690 https://doi.org/10.1016/j.coastaleng.2021.104063 |
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ftoskarbordeaux:oai:oskar-bordeaux.fr:20.500.12278/184690 2023-12-10T09:51:45+01:00 Modelling the contribution of wind waves to Cap Ferret's updrift erosion Coastal Engineering NAHON, Alphonse IDIER, Deborah BERTIN, Xavier GUERIN, Thomas MARIEU, Vincent SENECHAL, Nadia MUGICA, Julie 2022-03-01 https://oskar-bordeaux.fr/handle/20.500.12278/184690 https://hdl.handle.net/20.500.12278/184690 https://doi.org/10.1016/j.coastaleng.2021.104063 EN eng 0378-3839 https://oskar-bordeaux.fr/handle/20.500.12278/184690 doi:10.1016/j.coastaleng.2021.104063 Attribution 3.0 United States open http://creativecommons.org/licenses/by/3.0/us/ Pas de Licence CC Sandspit Tidal inlet Sediment transport Wave power NAO SCHISM Sciences de l'environnement Article de revue 2022 ftoskarbordeaux https://doi.org/20.500.12278/18469010.1016/j.coastaleng.2021.104063 2023-11-14T23:30:44Z Wind waves breaking at an angle with the shoreline force the drifting of littoral sediments, which is known for contributing to the formation and growth of barrier spits. Intriguingly, increased rates of longshore wave power have also been associated with the erosion of some barrier spits on the updrift margin of tidal inlets. Therefore, a numerical experiment was designed and is presented here, which investigates the possible links between the longshore wave power and the shortening of these elongated coastal barriers. Based on a process-based model, the experiment provides new insights into the forces at play in the redistribution of sediments between a sandspit and its adjacent inlet, respectively the Cap Ferret and the Bay of Arcachon's tidal inlet, in SW France. More particularly, model scenarios were defined that show how combined waves and tide create gradients of residual sediment transport responsible for a sediment deficit at the spit – inlet boundary. The deficit was also found to deepen with increasing longshore wave energy, as if the transfer of sediment from the spit to inlet shoals was accelerated. This physically explains the previously observed retreat of the spit's distal end during periods dominated by the positive phase of North Atlantic Oscillation (NAO) in winter. Indeed, according to model results, higher and/or more oblique waves associated with the positive phase of the NAO are expected to increase the transfer and storage of the drifting sediments to and by the inlet shoals, and this at the expense of the spit. While these conclusions remain valid, we noticed that the sensitivity of model results to the bottom friction enhanced the importance of accurately representing the spatio-temporal distribution of bed roughness when investigating the morphodynamic interactions between real-world tidal inlets and their margins. Article in Journal/Newspaper North Atlantic North Atlantic oscillation OSKAR Bordeaux (Open Science Knowledge ARchive) Sandspit ENVELOPE(-131.827,-131.827,53.244,53.244) The Spit ENVELOPE(170.217,170.217,-71.300,-71.300) Coastal Engineering 172 104063 |
institution |
Open Polar |
collection |
OSKAR Bordeaux (Open Science Knowledge ARchive) |
op_collection_id |
ftoskarbordeaux |
language |
English |
topic |
Sandspit Tidal inlet Sediment transport Wave power NAO SCHISM Sciences de l'environnement |
spellingShingle |
Sandspit Tidal inlet Sediment transport Wave power NAO SCHISM Sciences de l'environnement NAHON, Alphonse IDIER, Deborah BERTIN, Xavier GUERIN, Thomas MARIEU, Vincent SENECHAL, Nadia MUGICA, Julie Modelling the contribution of wind waves to Cap Ferret's updrift erosion |
topic_facet |
Sandspit Tidal inlet Sediment transport Wave power NAO SCHISM Sciences de l'environnement |
description |
Wind waves breaking at an angle with the shoreline force the drifting of littoral sediments, which is known for contributing to the formation and growth of barrier spits. Intriguingly, increased rates of longshore wave power have also been associated with the erosion of some barrier spits on the updrift margin of tidal inlets. Therefore, a numerical experiment was designed and is presented here, which investigates the possible links between the longshore wave power and the shortening of these elongated coastal barriers. Based on a process-based model, the experiment provides new insights into the forces at play in the redistribution of sediments between a sandspit and its adjacent inlet, respectively the Cap Ferret and the Bay of Arcachon's tidal inlet, in SW France. More particularly, model scenarios were defined that show how combined waves and tide create gradients of residual sediment transport responsible for a sediment deficit at the spit – inlet boundary. The deficit was also found to deepen with increasing longshore wave energy, as if the transfer of sediment from the spit to inlet shoals was accelerated. This physically explains the previously observed retreat of the spit's distal end during periods dominated by the positive phase of North Atlantic Oscillation (NAO) in winter. Indeed, according to model results, higher and/or more oblique waves associated with the positive phase of the NAO are expected to increase the transfer and storage of the drifting sediments to and by the inlet shoals, and this at the expense of the spit. While these conclusions remain valid, we noticed that the sensitivity of model results to the bottom friction enhanced the importance of accurately representing the spatio-temporal distribution of bed roughness when investigating the morphodynamic interactions between real-world tidal inlets and their margins. |
format |
Article in Journal/Newspaper |
author |
NAHON, Alphonse IDIER, Deborah BERTIN, Xavier GUERIN, Thomas MARIEU, Vincent SENECHAL, Nadia MUGICA, Julie |
author_facet |
NAHON, Alphonse IDIER, Deborah BERTIN, Xavier GUERIN, Thomas MARIEU, Vincent SENECHAL, Nadia MUGICA, Julie |
author_sort |
NAHON, Alphonse |
title |
Modelling the contribution of wind waves to Cap Ferret's updrift erosion |
title_short |
Modelling the contribution of wind waves to Cap Ferret's updrift erosion |
title_full |
Modelling the contribution of wind waves to Cap Ferret's updrift erosion |
title_fullStr |
Modelling the contribution of wind waves to Cap Ferret's updrift erosion |
title_full_unstemmed |
Modelling the contribution of wind waves to Cap Ferret's updrift erosion |
title_sort |
modelling the contribution of wind waves to cap ferret's updrift erosion |
publishDate |
2022 |
url |
https://oskar-bordeaux.fr/handle/20.500.12278/184690 https://hdl.handle.net/20.500.12278/184690 https://doi.org/10.1016/j.coastaleng.2021.104063 |
long_lat |
ENVELOPE(-131.827,-131.827,53.244,53.244) ENVELOPE(170.217,170.217,-71.300,-71.300) |
geographic |
Sandspit The Spit |
geographic_facet |
Sandspit The Spit |
genre |
North Atlantic North Atlantic oscillation |
genre_facet |
North Atlantic North Atlantic oscillation |
op_relation |
0378-3839 https://oskar-bordeaux.fr/handle/20.500.12278/184690 doi:10.1016/j.coastaleng.2021.104063 |
op_rights |
Attribution 3.0 United States open http://creativecommons.org/licenses/by/3.0/us/ Pas de Licence CC |
op_doi |
https://doi.org/20.500.12278/18469010.1016/j.coastaleng.2021.104063 |
container_title |
Coastal Engineering |
container_volume |
172 |
container_start_page |
104063 |
_version_ |
1784897546328473600 |