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| Titre : | Relevé haute fréquence des Barres et bâches entre la baie de somme et la baie d'Authie : Déplacement des structures – Descriptions morphologiques |
| Auteurs : | Nicolas AIME ; Priscille VIELLEFON |
| Type de document : | Mémoire d'initiation à la recherche |
| Année de publication : | 2020 |
| Concepts : |
BAR
DGPS |
| Résumé : | This work is the result of analyzes and processing of data from a field campaign that enabled the high-frequency survey of the bars and runnels on the foreshore between the Baie de Somme and the Baie d'Authie using a DGPS in September 2019. This survey took place in three areas, from South to North, the “Bouchots” area, the “Quend-Plage” area and the area of “Fort-Mahon”. Each zone has its particularities between shellfish farming, embankment, drainage system or preserved sector. The challenge of this work lies in a better understanding of the bars and channels dynamics in the study areas. The aim is to quantify the displacement of structures, to compare these results with other studies, but also to identify the major players in these displacements. In addition, the morphologies of sedimentary structures also contribute to this work. After processing the DGPS readings on ArcGis Pro, measurements of bar and channel displacement could finally be made for the movement speeds of the structures according to their position on the foreshore, the study area or even according the forcing agents. Maps were produced to visualize the morphologies and movements of the sand bars. The sedimentary figures recorded in the field were listed in a table and commented. The work carried out reveals a coherence between the travel speeds found and previous studies. Forcing agents, wind, tide, waves play a role in the displacement of structures with each their specific influence. A profile of the speed of movement of the bars was also highlighted according to the study area and the local context. In addition, the coastal drift speed calculated is 1.68 m / day. |
| Spécialité : | Géologie |
| Numéro de promo : | 82 |
| numéro MIR : | 868 |
