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| Registros recuperados: 53 | |
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| Alekseenko, Elena; Roux, Bernard; Sukhinov, A.; Kotarba, R.; Fougere, D.. |
| The nonlinear hydrodynamics (3D RANS model) in a wide semi-enclosed windy lagoonal ecosystem is accurately investigated in the context of analyzing the limiting conditions of the recovery of submerged aquatic vegetation (SAV). Among the main natural hydrodynamical forcings, we consider the wind effect. We mainly focus attention to characteristic velocities (free surface and bottom) and to free surface elevation in the nearshore regions (with shallow water) where SAV were severely damaged in the past decades. Our main result relates to wind effects that form downwind coastal jets, alongshore, in shallow water areas, due to Berre bathymetry. Such coastal jets, which were never described previously in Berre lagoon literature, give rise to substantial bottom... |
| Tipo: Text |
Palavras-chave: Hydrodynamics; Berre lagoon; Current structures; Zostera noltii; Seagrass protection. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00144/25511/24704.pdf |
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| Bailly Du Bois, P; Dumas, Franck; Morillon, M; Furgerot, L; Voiseux, C; Poizot, E; Mear, Y; Bennis, Anne-claire. |
| This study presents an overview of the main hydrodynamic features of the Alderney Race strait based on in-situ measurements and 2D hydrodynamic model simulations. The strait encompasses a large amplitude of tidal properties (tidal range and tidal wave propagation) and particularly strong currents exceeding 5 m.s-1 with associated counter currents and gyres. Variations in depth, sea bottom roughness, coastal topography and current orientation around the La Hague Cape provide access to a large variety of original hydrodynamic regimes. Some are revealed as locations with a 0.4 m drop in the mean sea level associated with strong average currents. A resonance effect associated with the offshore currents can also be observed close to the coasts. The "St Martin... |
| Tipo: Text |
Palavras-chave: Alderney Race; La Hague Cape; Current; Tide; Hydrodynamics; Model. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00641/75286/75639.pdf |
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| Cognat, Mathis; Ganthy, Florian; Auby, Isabelle; Barraquand, Frederic; Rigouin, Loic; Sottolichio, Aldo. |
| The relative impact of light, depth, hydrology, hydrodynamics, sediment and nutrients on growth of the seagrass Zostera noltei was investigated in Arcachon Bay, where the extent of seagrass beds has been decreasing for 20 years. A comprehensive multi-parameter survey of 9 sites was conducted monthly over one year. A three-parameter logistic growth model was fitted to biomass data to unravel the relative contributions of environmental factors on seagrass growth. The present study highlights the fact that, in addition to the dominant positive effect of light on plant growth, the hydrological and hydrodynamic parameters were important drivers for Z. noltei growth at the scale of the whole Bay. At the scale of individual sites, other factors such as macroalgal... |
| Tipo: Text |
Palavras-chave: Physical parameters; Light; Hydrodynamics; Adaptation; Statistical growth model. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00451/56229/57789.pdf |
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| Ouillon, S.; Douillet, Pascal; Lefebvre, J. P.; Le Gendre, Romain; Jouon, Aymeric; Bonneton, P.; Fernandez,; Chevillon, C.; Magand, O.; Lefevre, J.; Le Hir, Pierre; Laganier, R.; Dumas, Franck; Marchesiello, P.; Madani, A. Bel; Andrefouet, S.; Panche, J. Y.; Fichez, R.. |
| The south-west lagoon of New Caledonia is a wide semi-open coral reef lagoon bounded by an intertidal barrier reef and bisected by numerous deep inlets. This paper synthesizes findings from the 2000-2008 French National Program EC2CO-PNEC relative to the circulation and the transport of suspended particles in this lagoon. Numerical model development (hydrodynamic, fine suspended sediment transport, wind-wave, small-scale atmospheric circulation) allowed the determination of circulation patterns in the lagoon and the charting of residence time, the later of which has been recently used in a series of ecological studies. Topical studies based on field measurements permitted the parameterisation of wave set-up induced by the swell breaking on the reef barrier... |
| Tipo: Text |
Palavras-chave: Hydrodynamics; Suspended sediment; New Caledonia; Coral reef lagoon; Sediment; Turbidity; Resuspension. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00014/12526/9401.pdf |
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| Grasso, Florent; Verney, Romaric; Le Hir, Pierre; Thouvenin, Benedicte; Schulz, Elisabeth; Kervella, Youenn; Fard, I. Khojasteh Pour; Lemoine, J. -p.; Dumas, Franck; Garnier, Valerie. |
| Tidal pumping, baroclinic circulation and vertical mixing are known to be the main mechanisms responsible for the estuarine turbidity maximum (ETM) formation. However, the influence of hydro-meteorological conditions on ETM dynamics is still not properly grasped and requires further investigation to be quantified. Based on a realistic 3-dimensional numerical model of the macrotidal Seine Estuary (France) that accounts for mud and sand transport processes, the objective of this study is to quantify the influence of the main forcing (river flow, tides, waves) on the ETM location and mass changes. As expected, the ETM location is strongly modulated by semidiurnal tidal cycles and fortnightly timescales with a high sensitivity to river flow variations. The ETM... |
| Tipo: Text |
Palavras-chave: Estuary; Mud; Sand; Hydrodynamics; Turbidity maximum; Waves; Measurement; Modeling. |
| Ano: 2018 |
URL: http://archimer.ifremer.fr/doc/00416/52770/53638.pdf |
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| Chary, Killian; Callier, Myriam; Coves, Denis; Aubin, Joel; Simon, Julien; Fiandrino, Annie. |
| Spatial planning, including zoning and site-selection steps, is necessary to determine locations that minimize environmental impacts of aquaculture and respect ecosystem carrying capacities. This study aimed to analyse potential benthic waste deposition in a broad range of fish farming situations to facilitate zoning. To this end, we simulated waste dispersion for 54 aquaculture scenarios combining three red drum (Sciaenops ocellatus) farm types (Small, Medium, and Large) based on real farm characteristics and 36 sites with contrasting hydrodynamics in Mayotte’s North-East Lagoon. Key forcing variables and parameters of the particle-dispersion model for farms (layout and solid waste fluxes), species (feed- and faeces-settling velocities) and sites (depth... |
| Tipo: Text |
Palavras-chave: Aquaculture zones; Carrying-capacity; Environmental impact; Hydrodynamics; NewDEPOMOD; Particle dispersion; Red drum; Scenario analysis. |
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00666/77810/79985.pdf |
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| Lupo, Coralie; Dutta, Bhagat Lal; Petton, Sebastien; Ezanno, P; Tourbiez, Delphine; Travers, Marie-agnes; Pernet, Fabrice; Bacher, Cedric. |
| Vibrio aestuarianus infection in oyster populations causes massive mortality, resulting in losses for oyster farmers. Such dynamics result from host-pathogen interactions and contagion through water-borne transmission. To assess the spatiotemporal spread of V. aestuarianus infection and associated oyster mortality at a bay scale, we built a mathematical model informed by experimental infection data at 2 temperatures and spatially dependent marine connectivity of oyster farms. We applied the model to a real system and tested the importance of each factor using a number of modelling scenarios. Results suggest that introducing V. aestuarianus in a fully susceptible adult oyster population in the bay would lead to the mortality of all farmed oysters over 6 to... |
| Tipo: Text |
Palavras-chave: Basic reproduction number; Crassostrea gigas; Hydrodynamics; Oyster disease; Sensitivity analysis; Vibrio aestuarianus. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00662/77459/79114.pdf |
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| Bacher, Cedric; Filgueira, R.; Guyondet, T.. |
| Markov Chain analysis was recently proposed to assess the time scales and preferential pathways into biological or physical networks by computing residence time, first passage time, rates of transfer between nodes and number of passages in a node. We propose to adapt an algorithm already published for simple systems to physical systems described with a high resolution hydrodynamic model. The method is applied to bays and estuaries on the Eastern Coast of Canada for their interest in shellfish aquaculture. Current velocities have been computed by using a 2 dimensional grid of elements and circulation patterns were summarized by averaging Eulerian flows between adjacent elements. Flows and volumes allow computing probabilities of transition between elements... |
| Tipo: Text |
Palavras-chave: Transfer time; Transfer rate; Residual flow; Indicators; Aquaculture; Hydrodynamics. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00280/39124/37677.pdf |
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| Jonsson, Per R.; Van Duren, Luca A.; Amielh, Muriel; Asmus, Ragnhild; Aspden, Rebecca J.; Daunys, Darius; Friedrichs, Michael; Friend, Patrick L.; Olivier, Frédéric; Pope, Nick; Precht, Elimar; Sauriau, Pierre-guy; Schaaff, Estelle. |
| Flume tanks are becoming increasingly important research tools in aquatic ecology, to link biological to hydrodynamical processes. There is no such thing as a "standard flume tank", and no flume tank is suitable for every type of research question. A series of experiments has been carried out to characterise and compare the hydrodynamic characteristics of 12 different flume tanks that are designed specifically for biological research. These facilities are part of the EU network BioFlow. The flumes could be divided into four basic design types: straight, racetrack, annular and field flumes. In each facility, two vertical velocity profiles were measured: one at 0.05 m s(-1) and one at 0.25 m s(-1). In those flumes equipped with Acoustic Doppler Velocimeters... |
| Tipo: Text |
Palavras-chave: Methods; Hydrodynamics; Flume tanks; Biological physical interaction; Benthic boundary layer. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-2242.pdf |
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| Boutron, Olivier; Bertrand, Olivier; Fiandrino, Annie; Hoehener, Patrick; Sandoz, Alain; Cherain, Yves; Coulet, Eric; Chauvelon, Philippe. |
| The spatiotemporal structure of wind-driven circulation patterns and associated water exchanges can drive important bio-hydrodynamic interactions in shallow lagoons. The Vaccares lagoon system is a complex shallow hydrosystem located in the central part of the Rhone Delta (France). It is internationally recognized as part of a biosphere reserve within the framework of UNESCO's Man and Biosphere Programme, and as a RAMSAR site. Due to its frequent occurrence in this area, and considering the shallowness of the Vaccares lagoon system, wind is assumed to play a major role in the hydrodynamic and biological processes. In this study, a hydrodynamic model was developed to investigate the structure of wind-driven circulations in the Vaccares lagoon system, to... |
| Tipo: Text |
Palavras-chave: Coastal lagoon; Mathematical model; Hydrodynamics; Calibration; Validation; Wind-driven circulation. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00303/41382/40558.pdf |
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| Registros recuperados: 53 | |
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