%0 Journal Article
%9 ACL : Articles dans des revues avec comité de lecture répertoriées par l'AERES
%A Taveneau, Adélaïde
%A Almar, Rafaël
%A Bergsma, E. W. J.
%A Cissé, C. O. T.
%A Sy, B. A.
%A Ndour, A.
%T Monitoring temporal sandbar and shoreline changes at Saint Louis, Senegal : using Sentinel-2 imagery (2015-2022)
%D 2024
%L fdi:010091971
%G ENG
%J Remote Sensing
%K satellites ; nearshore sandbar ; landward migration ; coastal engineering
%K SENEGAL
%M ISI:001332911800001
%N 19
%P 3551 [14 ]
%R 10.3390/rs16193551
%U https://www.documentation.ird.fr/hor/fdi:010091971
%> https://horizon.documentation.ird.fr/exl-doc/pleins_textes/2024-11/010091971.pdf
%V 16
%W Horizon (IRD)
%X Understanding beach dynamics, both in time and in space, is paramount to better understand how and when to intervene to improve coastal management strategies. Beach morphodynamics is expressed in a variety of ways. As indicators of beach change, we can measure the shoreline, the beach topography, and the bathymetry; e.g., in situ measurements rarely cover large extents, are often collected on a local scale (beach), and rarely cover a sufficient time span with a sufficient surveying frequency or a simultaneous measurement of the beach and bar system. Regular-revisit satellites, such as the ESA's Sentinel-2 mission, provide the opportunity to regularly monitor both shoreline and sandbar dynamics, and the time span is increasing and likely to continue for the decades to come. Using the satellite-derived shoreline and bar position, here, we show that the shoreline and bar are intrinsically coupled. Using Sentinel-2 satellite imagery, we show that the actual erosion/accretion status of the beach at Saint Louis (Senegal) is strongly influenced by the sandbar dynamics. There is a coupled behavior in their seasonal evolution and trend. Our results show that a very large accretive wave of about 50 m observed on the beach is driven by a local welding of the inner sandbar to the beach. Finally, we conclude that this type of event could be anticipated by an analysis of the sandbar.
%$ 126 ; 064 ; 021