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Maps of field sites in south-eastern France (1.a), Vaccarès (1.b) and Berre (1.c) lagoons, bed elevation in NGF referential (official levelling network in metropolitan France).

Maps of field sites in south-eastern France (1.a), Vaccarès (1.b) and Berre (1.c) lagoons, bed elevation in NGF referential (official levelling network in metropolitan France).

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Article
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The present paper is specifically focused on enclosed or semi-enclosed basins where the wind is the dominant driver of water surface tilting, leading to the so-called wind tide contributing to water levels rise. Wind-induced free surface tilting is studied using the 1-D steady form of the depth-averaged shallow water (Saint-Venant) momentum equatio...

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Context 1
... the EDF hydroelectric plant at Saint-Chamas sporadically discharges large quantities of fresh water and silt into Berre lagoon at high volumes, up to more than once the volume of the lagoon per year. Berre lagoon can be classified as a choked coastal lagoon ( Mahapatro et al., 2013) with a restricted communication with the sea via the Caronte channel, a channel with a maximum width of about 200 meters, 6 km long and with a bathymetry between 7 and 10 m., see figure 1.c 140 and further details in Section 2.2.2. ...
Context 2
... mentioned in section 2.2.2, the mean water depth h is assumed to be spatially-uniform but is also presented in figure 4, the station is located 1n figure 1.c. The span of the experiments ensured to cover a wide range of conditions at both lagoons, with several strong wind events in both main directions (NW and SE). the Caronte channel. ...
Context 3
... the EDF hydroelectric plant at Saint-Chamas sporadically discharges large quantities of fresh water and silt into Berre lagoon at high volumes, up to more than once the volume of the lagoon per year. Berre lagoon can be classified as a choked coastal lagoon ( Mahapatro et al., 2013) with a restricted communication with the sea via the Caronte channel, a channel with a maximum width of about 200 meters, 6 km long and with a bathymetry between 7 and 10 m., see figure 1.c and further details in Section 2.2.2. ...
Context 4
... observational data are obtained from the international surface observation messages (SYNOP) circulating on the global telecommunication system (GTS) of the World Meteorological Organization (WMO). Wind data for Vaccarès lagoon were provided from July 2019 to August 2020 by hourly wind measurements at the Tour-du-Valat station (Météo-France), see figure 1.b. For both wind data sources, the average wind speed data are the average over the last 10 minutes before the selected time with a sampling period of 1 minute. ...
Context 5
... locations depicted in figure 1.b were determined based on prevailing wind conditions but at Saint-Chamas and Le Jaï harbours (see figure 1.c), i.e. roughly in the dominant wind axis, to provide pressure and temperature data every 2 minutes. ...

Citations

... The impact of wind is rarely considered when describing the multiple and complex mechanisms driving the morphodynamics of intermittent estuaries, even though wind can have a considerable influence on the internal lagoon morphology [42,43]. This is especially important in shallow basins where wind forcing can produce surges of significant amplitude [44][45][46][47][48]. These surges can be comparable in magnitude to the effects produced by river discharges and could thus potentially contribute to controlling an intermittent estuary if the surge is directed toward the barrier. ...
... In addition to lowering the beach profile due to erosion processes, offshore winds cause a tilting of the lagoon water surface towards the barrier (Figure 12b); strong offshore winds can blow for weeks during this period. The amplitude of these surges is controlled by the shape of the basin (area and depth) as well as by the wind speed [44][45][46][47][48]. The surges are intensified by increasing basin length, higher wind speed, and increasingly shallow water depth. ...
Article
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This study focuses on the dynamics of an intermittent estuary in a wave-dominated (mi-crotidal) area, with low fluvial discharges and strong dominant offshore wind regimes. The aims are to understand the effect of these particular environmental factors in the dynamics of such estuaries. The results allow us to propose a synthetic morphodynamic model of evolution whereby opening phases are predominantly controlled by offshore winds, which have a significant influence in the northern Mediterranean. Inputs from rainfall/karst discharge and the overtopping of storm waves cause the lagoon to fill. Closing phases are controlled by the slight easterly swell which forms a berm at the inlet entrance. On occasion, major storms can also contribute to barrier opening. Nevertheless , offshore wind remains the main controlling factor allowing the surge of lagoon waters behind the beach barrier and the lowering of the berm by wind deflation. This leads to opening of the barrier due to the overflow of lagoon waters at the beach megacusp horns, thus connecting the sub-aerial beach with the inner bar system that is developed on topographically low sectors of the barrier. To the best of the authors' knowledge, this type of estuary is not described in the literature.
... Although the seashore of the Rhône Delta is subject to a micro-tidal regime (the difference between the lowest and highest value of astronomic tide is 0.42 m, see [25]), the "Vaccarès lagoon system" is not impacted by a tidal regime, [26], due to the small size of the sluice gates in comparison with the area of the Vaccarès Lagoon System, and to their management, with the opening of more than five sluices carried out to decrease water level and mass of salt into the lagoons (flows from the lagoons into the sea). ...
... Due to their shallow depth, Mediterranean coastal lagoons are generally strongly impacted by the wind in terms of water levels [23]. The duration and intensity of the variations of these levels can be more or less important, depending on the geomorphological characteristics of the lagoons considered, and on the local wind dynamics [26]. The time scales of these tilts generally range from several hours to a few days, requiring continuous monitoring ensured by the use of probes in different locations of the lagoon. ...
... Preliminary modeling studies [45] suggest that an absence of regulation on the Vaccarès Lagoon System, including the permanent opening of the 13 sluice gates of the Fourcade, would lead to high water levels in the lagoons. In combination with the influence of wind [23,26], these high water levels would cause bank erosion and regular flooding of the surrounding areas. This work also suggests that it would lead to a significant and longterm increase in the dissolved salt mass and overall salinities. ...
Article
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The Vaccarès Lagoon System, located in the central part of the Rhône Delta (France), is a complex shallow coastal lagoon, exposed to a typical Mediterranean climate and a specific hydrological regime affected by man-controlled exchanges with the sea and agricultural drainage channels. In this article, we report the results obtained by a series of monitoring programs, with different spatial and temporal resolutions. Long-term datasets from 1999 to 2019 with data collected on a monthly basis and a high spatial resolution highlighted the significant spatial heterogeneity in salinity regimes, and helped to determine the long-term evolution of the total mass of dissolved salt. High-frequency surveys allowed to characterize the water levels and salinity dynamics seasonal response to (i) the exchanges with the Mediterranean Sea, (ii) the exchanges with agricultural drainage channels, and (iii) the rain and evaporation. In addition, wind effects on salinity variations are also explored. This work shows how different spatial and temporal monitoring strategies provide complementary information on the dynamic of such a complex system. Results will be useful and provide insight for the management of similar lagoon systems, accommodating for both human activities and ecological stakes in the context of global change.