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Registros recuperados: 37 | |
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Gonzalez, Jean-louis; Dange, Catherine; Thouvenin, Benedicte. |
In estuarine environment, cadmium has a nonconservative behavior. It can be present under various species: dissolved (mineral and organic complexes), colloidal and particulate forms (adsorbed, precipitated), or integrated by various mechanisms in the organisms. This distribution is the result of processes (physical, chemical and biological) which are controlled by many factors (salinity, pH, Eh, nature and concentration of suspended matter, primary production). Geochemical modeling is a very useful approach to understand the dynamics of this type of contaminant, especially in the complex systems which are the estuaries. A speciation model was used to simulate the measurements taken (dissolved and particulate Cd) during various cruises carried out in the... |
Tipo: Text |
Palavras-chave: Cadmium; Estuary; Speciation; Modeling; Surface complexation; Cadmium; Estuaire; Spéciation; Modélisation; Complexation de surface. |
Ano: 2001 |
URL: https://archimer.ifremer.fr/doc/00480/59120/61749.pdf |
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Jany, Cassandre; Pairaud, Ivane; Thouvenin, Benedicte; Verney, Romaric. |
In the context of the METROC project, academic modelling of dissolved and particulate materials were done with the MARS3D model. Considering the dissolved materials, we calculated evacuation times and residence times. Then, we add minimal dilution and percentile maps to assimilate the modelling and the realistic dissolved metal discharge. Considering the particulate materials, we did balance sheets for material exported, sedimenting or staying in water for three different phases (whole modelling 13 October – 31 December 2008, flood situation and resuspension situation). Maps of Marseille roadstead complete that information and allow visualising the principal deposition area. We will continue this work by modelling reel material such as Lead. |
Tipo: Text |
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Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00090/20088/17724.pdf |
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Plus, Martin; Auby, Isabelle; Maurer, Daniele; Trut, Gilles; Del Amo, Y.; Dumas, Franck; Thouvenin, Benedicte. |
This study presents an assessment of the contributions of various primary producers to the global annual production and N/P cycles of a coastal system, namely the Arcachon Bay, by means of a numerical model. This 3D model fully couples hydrodynamic with ecological processes and simulates nitrogen, silicon and phosphorus cycles as well as phytoplankton, macroalgae and seagrasses. Total annual production rates for the different components were calculated for different years (2005, 2007 and 2009) during a time period of drastic reduction in seagrass beds since 2005. The total demand of nitrogen and phosphorus was also calculated and discussed with regards to the riverine inputs. Moreover, this study presents the first estimation of particulate organic carbon... |
Tipo: Text |
Palavras-chave: Primary production; Macrophyte; Phytoplankton; Biogeochemical cycle; Physical-ecological coupled model; Arcachon bay. |
Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00278/38963/37503.pdf |
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Grasso, Florent; Schulz, Elisabeth; Le Hir, Pierre; Verney, Romaric; Thouvenin, Benedicte. |
La dynamique sédimentaire à l’embouchure de l’estuaire de Seine est principalement contrôlée par les forçages hydrométéorologiques (débit, vent, vagues, marée) et les fortes pressions anthropiques (endiguement, dragage, clapage). La compréhension et la quantification de la dynamique des flux sédimentaires en suspension (sable/vase) est un enjeu majeur, autant d’un point vu écologique (ex. turbidité, envasement) que financier (ex. gestion des chenaux de navigation). La mise en place de réseaux de mesure in situ permet une meilleure compréhension de la dynamique sédimentaire de l’estuaire, mais leur caractère local rend difficile toute estimation des flux et bilans sédimentaires. Pour répondre à ces questions, cette étude s’appuie sur la modélisation... |
Tipo: Text |
Palavras-chave: Dynamique hydro-sédimentaire; Sable/vase; Estuaire de Seine; Modélisation numérique; Mesures in situ; Dragage; Flux résiduels et bilans; Année/trimestres. |
Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00348/45928/45621.pdf |
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Menesguen, Alain; Desmit, Xavier; Duliere, Valerie; Lacroix, Genevieve; Thouvenin, Benedicte; Thieu, Vincent; Dussauze, Morgan. |
Since 1950, increase in nitrogen (N) and phosphorus (P) river loadings in the North-East Atlantic (NEA) continental seas has induced a deep change in the marine coastal ecosystems, leading to eutrophication symptoms in some areas. In order to recover a Good Ecological Status (GES) in the NEA, as required by European Water Framework Directive (WFD) and Marine Strategy Framework Directive (MSFD), reductions in N- and P-river loadings are necessary but they need to be minimal due to their economic impact on the farming industry. In the frame of the “EMoSEM” European project, we used two marine 3D ecological models (ECO-MARS3D, MIRO&CO) covering the Bay of Biscay, the English Channel and the southern North Sea to estimate the contributions of various... |
Tipo: Text |
Palavras-chave: Marine eutrophication; Ecosystem modelling; Nutrient reduction scenario; Linear optimization; Good ecological status; EU policies. |
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00426/53774/54661.pdf |
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Thouvenin, Benedicte; Romana, Louis-alexandre. |
Depuis plusieurs années, on observe en période post-estivale un très important déficit en oxygène dissous dans l'estuaire de la Loire, accompagné par une mortalité élevée de certaines espèces halieutiques migratrices. L'origine de cette anoxie est imputée au stock de matière organique particulaire biodégradable qui est piégée dans la zone de turbidité maximale. A la demande de l'Association pour la Protection de l'Environnement de l'Estuaire de la Loire, un modèle mathématique a été mis en place pour décrire les mécanismes hydrodynamiques et hydrosédimenraires dans l'estuaire, ainsi que l'évolution de l'oxygène dissous et la dégradation de la matière organique. Dans une première phase, ce modèle reproduit l'évolution longitudinale et temporelle de... |
Tipo: Text |
Palavras-chave: Modèle mathématique; Estuaire; Loire; Oxygène dissous; Matière organique. |
Ano: 1992 |
URL: http://archimer.ifremer.fr/doc/00439/55039/56471.pdf |
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Thouvenin, Benedicte. |
Dans le cadre du programme national "REJETS URBAINS EN MER", développé par l'IFREMER, en collaboration avec l'Agence de Bassin Rhône Méditerranée Corse, des études sur le comportement d'un effluent émis par un émissaire en profondeur ont été réalisées. Complétant des mesures courantométriques et hydrologiques de longue durée, en un point à la sortie de l'émissaire de TOULON EST, deux modèles mathématiques ont été appliqués pour reproduire et étudier le rejet pendant les deux étapes de dilution. · Le modèle JET, développé par la SOGREAH, a été testé et comparé avec des mesures in situ. Les variations des résultats en fonction des conditions du milieu rencontrées pendant un cycle annuel ont été étudiées. Un modèle de transport et mélange multicouches a été... |
Tipo: Text |
Palavras-chave: Rejet urbain; Modèle mathématique; Rade de Toulon; Dispersion; Contamination. |
Ano: 1992 |
URL: http://archimer.ifremer.fr/doc/00132/24287/22285.pdf |
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Desmit, Xavier; Lacroix, Geneviève; Thieu, Vincent; Menesguen, Alain; Dulière, Valerie; Campuzano, Francisco; Billen, Gilles; Neves, Ramiro; Lancelot, Christiane; Gypens, Nathalie; Dussauze, Morgan; Garnier, Josette; Silvestre, Marie; Passy, Paul; Lassaletta, Luis; Guittard, Gabriel; Théry, Sylvain; Thouvenin, Benedicte; Garcia, Carla; Pinto, Ligia; Sobrinho, Joao; Mateus, Marco; Ascione Kenov, Isabella. |
One of the leading challenges in marine science and governance is to improve scientific guidance of management measures to mitigate eutrophication nuisances in the EU seas. Too few approaches integrate the eutrophication process in space (continuum river-ocean) and in time (past, present and future status). A strong need remains for (i) knowledge/identification of all the processes that control eutrophication and its consequences, (ii) consistent and harmonized reference levels assigned to each eutrophication-related indicator, (iii) identification of the main rivers directly or indirectly responsible for eutrophication nuisances in specific areas, (iv) an integrated transboundary approach and (v) realistic short term and long term nutrient reduction... |
Tipo: Text |
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Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00292/40301/38750.pdf |
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Oursel, B.; Garnier, C.; Pairaud, Ivane; Omanovic, D.; Durrieu, G.; Syakti, A. D.; Le Poupon, C.; Thouvenin, Benedicte; Lucas, Y.. |
The evaluation of contaminant net fluxes from the coast to the open sea requires the study of terrigeneous particles behaviour and fate. We studied the particles issued from two small coastal rivers whose waters are mixed with treated wastewater (TWW) coming from the Marseille wastewater treatment plant (WWTP) just before discharge to the Mediterranean Sea. An experimental device was developed and used to investigate particles settling rates, size distribution and metallic contamination when mixing with seawater. The particles were sampled in flood deposits of rivers and outlets during rainy periods and in the outlet water during dry periods. The flood deposits were mainly composed of 50–200 μm-sized particles, higher metals content being observed in the... |
Tipo: Text |
Palavras-chave: Particles contamination; Urban rivers; Coastal zone; TWW; Hydro sedimentation modelling. |
Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00169/28066/27277.pdf |
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Thouvenin, Benedicte. |
Une série de campagnes a été effectuée pendant l'été 1983 en baie de VILAINE afin d'étudier les phénomènes d'anoxie au niveau du fond. Un point de mesure "OXYMOR" a été choisi pour suivre l'evolution de l'oxygène au fond en même temps que la température sur la verticale, les courants et la salinité au fond et en surface. |
Tipo: Text |
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Ano: 1984 |
URL: http://archimer.ifremer.fr/doc/00081/19210/16805.pdf |
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Romana, Louis-alexandre; Thouvenin, Benedicte; Galenne, B.; Casanova, C.. |
The dissolved oxygen is a sensitive parameter for the environment quality. It is subjected to important variations in macrotidal estuaries with significant results on the fauna. It's why we can notice the important mullet death note in the Estuary of the Loire during sommer time. The supply of biodegradable organic substances in the maximum turbidity zone led to an important dissolved oxygen demand. It's the example of the Estuary of the Loire where we can watch this main fonction. A detailed study has begun on the dissolved oxygen cycle to compare the biochemical particulate and dissolved oxygen demand. This study collects in situ parameters, either of the environment evolution or of the dissolved oxygen cycle with specifie researches on the rate of... |
Tipo: Text |
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Ano: 1990 |
URL: https://archimer.ifremer.fr/doc/00480/59123/61751.pdf |
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Bacq, Nicolas; Cugier, Philippe; Grasso, Florent; Le Gendre, Romain; Le Hir, Pierre; Lemoine, Jean-philippe; Riou, Philippe; Schulz, Elisabeth; Thouvenin, Benedicte; Verney, Romaric. |
Dans le cadre du programme de recherche Seine-Aval 5, différentes stratégies de modélisation numérique sont mises en place pour aider à répondre aux questionnements scientifiques et sociétaux associés au fonctionnement physique, biologique, chimique et écologique de l'estuaire de la Seine (ex. projets RESET et HYMOSED). Les forçages météo-marins (vent, vague, marée) et hydrologique (débit) contrôlent le fonctionnement hydro-morpho-sédimentaire et biogéochimique de l'estuaire, modifiant ainsi les paramètres environnementaux de l’estuaire amont jusqu’à la baie de Seine (ex. nature des fonds, courant, turbidité, salinité, température, oxygène dissous, chlorophylle-a). La modélisation de ces paramètres, ainsi que leur évolution face à différents scénarios... |
Tipo: Text |
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Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00284/39480/37966.pdf |
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Diaz, Melanie; Grasso, Florent; Le Hir, Pierre; Caillaud, Matthieu; Thouvenin, Benedicte. |
Coastal environments are directly influenced by terrigenous inputs coming from rivers through estuaries. Quantifying the amount of nutrients and contaminants brought by sediments from continental areas to the sea is of major interest for marine resource protection. The complexity of the intra-estuarine dynamics, associated with the strong variability of meteorological forcing makes it difficult to quantify the residence time of particles within the estuary and the accumulation and dispersion areas offshore the mouth. Moreover, the dynamics of fine sediment trapping areas in the adjacent continental shelf (e.g. temporary or permanent storage such as the “West-Gironde Mud Patch” (WGMP) ) remains extremely challenging to address. Based on a realistic... |
Tipo: Text |
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Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00514/62559/66913.pdf |
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Registros recuperados: 37 | |
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