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Blaise, Emmanuel; Suanez, Serge; Stephan, Pierre; Fichaut, Bernard; David, Laurence; Cuq, Veronique; Autret, Ronan; Houron, Julien; Rouan, Mathias; Floc'H, France; Ardhuin, Fabrice; Cancouet, Romain; Davidson, Robert; Costa, Stephane; Delacourt, Christophe. |
Between December 2013 and March 2014, a cluster of about 12 storm events hit the coast of Brittany with an exceptional frequency. It was in February that these storm events were the most frequent and particularly virulent. The significant wave heights measured off Finistere reached respectively 12.3 m and 12.4 m during Petra and Ulla storms on February 5 and 14. However, analysis of hydrodynamic conditions shows that only three episodes promoted extreme morphogenetic conditions because they were combined with high spring tide level. The first one occurred on January 1 to 4, it was followed by events from February 1 to 3, and March 2-3. During these three extreme events observed tide levels were above highest astronomical tide level (HAT). Maximum surge... |
Tipo: Text |
Palavras-chave: Tempête; Érosion; Trait de côte; Marée de vive-eau; Bretagne; Surcote; Storm; High spring tide; Surge; Erosion; Shoreline; Brittany. |
Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00310/42171/43029.pdf |
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Jaud, Marion; Delacourt, Christophe; Le Dantec, Nicolas; Allemand, Pascal; Ammann, Jerome; Grandjean, Philippe; Nouaille, Henri; Prunier, Christophe; Cuq, Veronique; Augereau, Emmanuel; Cocquempot, Lucie; Floc'H, France. |
In the dual context of coastal hazard intensification and the growing number of stakes exposed to these hazards, coastal observatories are in demand to provide a structured framework dedicated to long-term monitoring. This article describes the drone-based photogrammetry monitoring performed since 2006 on Porsmilin Beach (Brittany, France) in the framework of the DYNALIT (Littoral and Coastline Dynamics) observatory, focusing on data quality and the consistency of long-term time series under the influence of multiple technological evolutions: Unmanned Aerial Vehicles (UAV) platforms with the arrival of electric multirotor drones, processing tools with the development of structure-from-motion (SfM) photogrammetry, and operational modes of survey. A study... |
Tipo: Text |
Palavras-chave: UAV; SfM photogrammetry; Coastal observatory; Beach monitoring. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00637/74927/76116.pdf |
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Suanez, Serge; Blaise, Emmanuel; Cancouet, Romain; Floc'H, France. |
An experimental study based on field measurements for runup parameterization was conducted on a high energy macrotidal beach located on North Brittany (Vougot Beach). The approach was based on morphological and hydrodynamic high frequency monitoring collected between 2008 and 2013. The aim was to quantify in-situ environmental conditions and dimensional swash parameters for the best calibration of Battjes (1971) runup formula. In addition, an empirical equation based on observed tidal water level and offshore wave height was produced to estimate extreme water levels defined as the sum of (i) astronomic tide, (ii) storm surge, and (iii) vertical wave runup. A good correlation between this empirical equation (1.01H(mo)xi(o)) and field runup measurements... |
Tipo: Text |
Palavras-chave: Macrotidal beach; Runup; Storm; Dune; Erosion; Extreme water level. |
Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00639/75097/75610.pdf |
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Masselink, Gerd; Castelle, Bruno; Scott, Tim; Dodet, Guillaume; Suanez, Serge; Jackson, Derek; Floc'H, France. |
Studies of coastal vulnerability due to climate change tend to focus on the consequences of sea level rise, rather than the complex coastal responses resulting from changes to the extreme wave climate. Here we investigate the 2013/2014 winter wave conditions that severely impacted the Atlantic coast of Europe and demonstrate that this winter was the most energetic along most of the Atlantic coast of Europe since at least 1948. Along exposed open-coast sites, extensive beach and dune erosion occurred due to offshore sediment transport. More sheltered sites experienced less erosion and one of the sites even experienced accretion due to beach rotation induced by alongshore sediment transport. Storm wave conditions such as were encountered during the 2013/2014... |
Tipo: Text |
Palavras-chave: Waves; Storms; Beaches; Atlantic; Europe. |
Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00606/71852/70473.pdf |
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Didier, David; Bernatchez, Pascal; Augereau, Emmanuel; Caulet, Charles; Dumont, Dany; Bismuth, Eliott; Cormier, Louis; Floc'H, France; Delacourt, Christophe. |
Increasingly used shore-based video stations enable a high spatiotemporal frequency analysis of shoreline migration. Shoreline detection techniques combined with hydrodynamic conditions enable the creation of digital elevation models (DEMs). However, shoreline elevations are often estimated based on nearshore process empirical equations leading to uncertainties in video-based topography. To achieve high DEM correspondence between both techniques, we assessed video-derived DEMs against LiDAR surveys during low energy conditions. A newly installed video system on a tidal flat in the St. Lawrence Estuary, Atlantic Canada, served as a test case. Shorelines were automatically detected from time-averaged (TIMEX) images using color ratios in low energy conditions... |
Tipo: Text |
Palavras-chave: Video monitoring; Shoreline detection; Beach morphology; Mobile terrestrial LiDAR; Erosion; Atlantic Canada. |
Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00638/75022/75656.pdf |
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Suanez, Serge; Cancouet, Romain; Floc'H, France; Blaise, Emmanuel; Ardhuin, Fabrice; Filipot, Jean-francois; Cariolet, Jean-marie; Delacourt, Christophe. |
Monitoring of dune erosion and accretion on the high-energy macrotidal Vougot beach in North Brittany (France) over the past decade (2004–2014) has revealed significant morphological changes. Dune toe erosion/accretion records have been compared with extreme water level measurements, defined as the sum of (i) astronomic tide; (ii) storm surge; and (iii) vertical wave runup. Runup parameterization was conducted using swash limits, beach profiles, and hydrodynamic (Hm0, Tm0,–1, and high tide water level—HTWL) data sets obtained from high frequency field surveys. The aim was to quantify in-situ environmental conditions and dimensional swash parameters for the best calibration of Battjes [1] runup formula. In addition, an empirical equation based on observed... |
Tipo: Text |
Palavras-chave: Macrotidal beach; Runup; Storm; Dune; Erosion; Extreme water level; NAO. |
Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00276/38765/37306.pdf |
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Moskalski, Susanne; Floc'H, France; Verney, Romaric. |
Residual suspended sediment flux in estuaries is dependent on water level, velocity, and suspended sediment concentration (SSC), but complex interactions between these variables and other forcing mechanisms can lead to drastic differences in the magnitude and direction of sediment flux. The goal of this study was to quantify residual suspended sediment flux in a shallow, macrotidal estuary, and to determine its most important forcing mechanisms, using the Dyer flux decomposition equation and a simplified analytical model. Water level, velocity, and acoustic backscatter were measured in the Aulne River estuary in Brittany, France, and acoustic backscatter converted to SSC. The vertical tide was slightly flood dominant near the mouth, but strongly flood... |
Tipo: Text |
Palavras-chave: Estuaries; Estuarine processes; Sediment flux decomposition; Brittany; Europe. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00588/70046/67981.pdf |
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