Skip to Main content Skip to Navigation
Theses

Dynamique morpho-sédimentaire de littoraux sableux macrotidaux à barres intertidales : modélisation numérique et expérimentations in situ

Abstract : The objective of this thesis was to compare sediment flux measurements and in situ morphological changes with 2DH numerical simulations on macrotidal beaches with intertidal bars. These comparisons were made on two beaches in the Nord Pas de Calais - Picardie ,Zuydcoote Beach and Hardelot Beach. These beaches are characterized by a straight sandy bar-trough system.This work allowed to acquire current data and wave data on the profile of each beach and also offshore data for a period of one week. Sediment flux measurements were also conducted using sediment traps and by monitoring bottom evolution using DGPS measurements at the beginning and the end of the campaigns.All these data were compared with results obtained by a digital 2DH model. This digital model is composed of three modules of the TELEMAC calculation chain, a module for taking into account the tidal currents, a spectral propagation module for the waves, and a sediment transport module with morphological evolution. Using these modules, simulations were performed for the duration of measurement campaigns to calibrate various parameters by comparing the results with in-situ measurements, including the Strickler coefficient, the wave-breaking index and four different sediment transport formulas.These simulations show the influence of the breaker index on both the hydrodynamic part and the sediment transport and morphological evolution.The different sediment transport formulas were used to determine their ability to reproduce the sediment transport measurements and the evolution according to the breaker value.This model has helped to highlight the role of waves and surges on the direction and intensity of the sediment transport as well as preferential areas of accretion and erosion. This study also shows some limitations of the model mainly on the speed perpendicular to the beach and the limitations caused by the use of a breaker index taking only into account the ratio between wave height and the deep, and limiting the surge on the crest of the bars and into the slope between the bar and the top trough on the beach.
Complete list of metadata

Cited literature [58 references]  Display  Hide  Download

https://tel.archives-ouvertes.fr/tel-01587735
Contributor : ABES STAR :  Contact
Submitted on : Thursday, September 14, 2017 - 3:58:49 PM
Last modification on : Friday, March 25, 2022 - 9:42:46 AM
Long-term archiving on: : Friday, December 15, 2017 - 3:24:17 PM

File

OUDART_2016_diffusion.pdf
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-01587735, version 1

Collections

UGA | CNRS | LEGI | STAR

Citation

Thibault Oudart. Dynamique morpho-sédimentaire de littoraux sableux macrotidaux à barres intertidales : modélisation numérique et expérimentations in situ. Mécanique des fluides [physics.class-ph]. Université Grenoble Alpes, 2016. Français. ⟨NNT : 2016GREAI057⟩. ⟨tel-01587735⟩

Share

Metrics

Record views

215

Files downloads

302