Publications scientifiques

In this paper, we proposed a new low cost technique of sea-level observation and monitoring inspired by the classical Tide Pole (Tide Staff). The results obtained by our proposed High Frequency Rotational Tide Gauge (RTG_HF) are promising. They show that RTG_HF is very adapted to an agitated environment and is able to measure high and low frequencies oscillations (waves/swells, infragravity waves, seiches, meteotsunamis, tsunamis, tides, sea-level change, etc.).

Sandy shorelines are constantly evolving, threatening frequently human assets such as buildings or transport infrastructure. In these environments, sea-level rise will exacerbate coastal erosion to an amount which remains uncertain. Sandy shoreline change projections inherit the uncertainties of future mean sea-level changes, of vertical ground motions, and of other natural and anthropogenic processes affecting shoreline change variability and trends. Furthermore, the erosive impact of sea-level rise itself can be quantified using two fundamentally different models.

In spite of the recent advances and the current perspectives of satellite radar altimetry to reach the coastline and monitor coastal sea level changes, this space-borne technology remains geocentric by essence. In contrast, the quantity that matters for coastal management and society is relative sea level. That is, the sea level relative to the land, as measured by conventional tide gauges. However, two important issues are associated with the use of tide gauges.

This paper concerns wind effect on bottom shear stress (BSS), resuspension and redeposition of bottom sediments in the nearshore areas of the Etang de Berre (EB), a semi-enclosed lagoon, in the context of Zostera noltei (Z.n.) restoration. As in our previous paper, the first step is to compare BSS with its threshold, BSS_cr, for a wind speed of 21 m/s. But, here, a new simulation is performed for 16 wind directions regularly spaced. It permits to analyze the combined effect, over one year, of these winds on the erosion risk.

Previous studies have proved that commercial, off-the-shelf, geodetic-quality Global Positioning System (GPS) receivers can monitor water level using multipath interferometric characteristics from the sea surface. A Lomb–Scargle periodogram (LSP) is typically used to extract the multipath frequency from the signal-to-noise ratio (SNR), which relates to the vertical distance between the antenna phase center and the reflecting surface, and subsequently, estimate sea levels.

Studies of macrotidal estuaries have been dominated by large, high-turbidity systems like the Gironde and Severn, but some macrotidal estuaries are different from these systems. The goal of this study was to document the state of hydrosedimentary processes in the macrotidal, low-turbidity Aulne River estuary and, where possible, compare it to a previous study. Study sites from a 1977 study were revisited in 2013. Observations of velocity, salinity, and suspended sediment concentration were analyzed and compared to the 1977 study, with particular attention given to hourly data.

La façade nord des Hauts-de-France correspond à une frange côtière de 60 km orientée OSO-ENE ouverte sur la mer du Nord. De nombreux bancs sableux sont présents le long de ce littoral où ils forment des corps sédimentaires massifs parallèles à obliques au trait de côte, localisés sur l’avant-côte jusqu’à plusieurs dizaines de mètres de profondeur. Des levés bathymétriques ont été exécutés depuis les années 1830 dans cette région. Les résultats de ces levés hydrographiques sont conservés au format papier dans les archives du Shom.

La hausse du niveau de la mer liée aux changements climatiques globaux demeure l'une des préoccupations sociétales majeures. L'analyse des données marégraphiques, constituant souvent les seules informations disponibles à l’échelle des décennies, voire des siècles passés, se révèle être un moyen idéal pour parvenir à dégager des tendances sur le long terme. Or, malgré un patrimoine historique marégraphique français conséquent, la majorité de ces mesures est encore sous forme papier et n’est donc pas exploitée.