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| Registros recuperados: 36 | |
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| Castaing, P; Allen, Gp; Houdart, Michel; Moign, Y. |
| The objective of this study, carried out in the Gironde estuary inlet, was to determine the nature of the seaward dispersion of estuarine water and suspended sediments during a spring tide and high river flow. On June 3, 19(7, three flights were made over the inlet, at mid ebb, low tide and mid flood. The planned flight at high tide was cancelled due to adverse meteorological conditions. During each flight, thermal infrared coverage was obtained, together with black and white photographs. These data were correlated with concomitant ground mesures of current velocity, salinity, temperature and suspended sediment concentration Four types of water masses were identified during the tidal cycle: estuarine "very warm and turbid" water; estuarine "cooler and... |
| Tipo: Text |
Palavras-chave: Hydrodynamique; Suspensions; Télédétection; Eaux côtières; Estuaire; Gironde; Hydrodynamic; Suspended sediments; Remote sensing; Coastal waters; Estuary; Gironde. |
| Ano: 1979 |
URL: http://archimer.ifremer.fr/doc/00122/23361/21188.pdf |
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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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| Masson, Daniel. |
| Suedre River, a small river in Charente-Maritime, is 45 km long and drains a 380 km2 river basin. Its flow rate is about 20 m3.s(-1). Beyond the Saujon agglomeration, the river extends to the sea via a 25-km long estuary which, through the action of tides, becomes a sea arm reaching 1 km in width. Freshwater and salt marshes line the banks of the Seudre River. Freshwater marshes are occupied by large cattle farms and intensive, irrigated crops. Salt marshes are used for oyster finishingthe final, fattening process in oyster farming. The coexistence of both types of activity is sometimes problematic, particularly in terms of water management, a frequent source of conflict. The climate in Charente-Maritime is characterised by dry summers and rainy winters,... |
| Tipo: Text |
Palavras-chave: Ostréiculture; Agriculture; Eau douce; Gestion eau; Seudre; Charente Maritime; Estuaire. |
| Ano: 1997 |
URL: http://archimer.ifremer.fr/doc/1997/acte-3211.pdf |
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| Muresan Paslaru, Bogdan. |
| The mercury cycle was explored in the Petit-Saut reservoir / Sinnamary Estuary continuum in French Guiana. Main processes involve (i) photo-induced reduction, (ii) adsorption and desorption at the particle surfaces, (iii) methylating bacterial activity, (iv) precipitation and dissolution of iron oxyhydroxides and sulfides. Sources of mercury to the Petit-Saut reservoir consist of the partly impacted river-tributaries, the atmospheric deposition and the flooded soils or vegetation. Once into the reservoir, divalent mercury undergoes a large spectrum of transformations including speciation and phase changes. We, here, probe these processes and demonstrate that the Petit-Saut reservoir behaves as a privileged site for atmospheric recycling and in situ... |
| Tipo: Text |
Palavras-chave: Atmosphere; Estuary; Reservoir; French Guiana; Methylmercury; Mercury; Atmosphère; Estuaire; Retenue; Guyane française; Methylmercure; Mercure. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/these-1508.pdf |
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| Piquet, Jean-come; Fillon, Alain; Thomas, Gerard. |
| L’estuaire de la Seudre est situé dans le bassin de Marennes-Oléron, au cœur de l’écosystème des Pertuis Charentais. L’estuaire alimente la majorité des surfaces de claire de la région, qui elle même, assure plus de la moitié de la commercialisation nationale. La contamination microbiologique de l’estuaire de la Seudre est donc un enjeu majeur pour l’ostréiculture. L’estuaire possède un bassin versant de faible dimension et dont le fonctionnement hydrologique est particulier. Il est relié à un très important ensemble de zones humides, et les débits d’eau douce sont dépendants de la gestion d’ouvrages hydrauliques. Les périodes d’étiage sont sévères et longues, et les apports d’eau douce à l’estuaire sont quasiment nuls en fin d’été et en début... |
| Tipo: Text |
Palavras-chave: Microbiologie; Contamination microbiologique; Bactériologie; Estuaire; Seudre; Charente Maritime. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00129/24048/22011.pdf |
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| Cabecadas, L. |
| Biomass and phytoplankton photosynthetic response were studied in the lower Tagus estuary weekly, and related to environmental conditions in February, March and April 1994. The Photosynthesis-Irradiance ((P-I)-I-B) relation was studied based on the light-saturated photosynthesis rate (P(B)m) and the light-limited initial slope (a(B)). The nutrient concentrations observed were high enough to be considered as not limiting phytoplankton growth. Tagus estuary phytoplankton seems, to a certain extent, adapted to high turbid conditions, being able to utilize the low light levels more efficiently, which was translated by high values of a(B) [0.10-0.20 mg C (mg Chl a)(-1) h(-1) (W m(-2))(-1)]; however, light seems to limit phytoplankton production in the water... |
| Tipo: Text |
Palavras-chave: Production primaire; Phytoplancton; Estuaire; Biomasse; Turbidité; Primary production; Phytoplankton; Estuary; Biomass; Turbidity. |
| Ano: 1999 |
URL: http://archimer.ifremer.fr/doc/00325/43621/43310.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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| Thomas, Gerard; Kantin, Roger; Heral, Maurice. |
| A coastal river 380 km long, the Charente river has a catchment area of about 10,000 km2, flowing through the departments of Charente and Charente-Maritime, as well as a small part of the border departments: Dordogne, Deux-Sèvres, Haute-Vienne and Vienne. Its main affluents are the Tardoire, the Seugne and the Boutonne rivers. The highest part of the catchment area is located in Dordogne, at a height of 496 m, whereas the river itself originates from a spring located at a height of 250 m to the south-east of Rochechouart, in the Haute-Vienne. The average height of the catchment area is quite low. In its downstream part, from the Saint-Savinien dam to the ocean, the Charente is influenced by a dynamic tide. The actual estuarine part begins in... |
| Tipo: Text |
Palavras-chave: Charente Maritime; Gestion eau; Qualité eaux; Conchyliculture; Capacité trophique; La Charente; Estuaire. |
| Ano: 1999 |
URL: http://archimer.ifremer.fr/doc/1999/publication-6289.PDF |
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| Bharathi, Pal; Oak, S; Chandramohan, D. |
| Sulfate-reducing bacteria (SRB) have been enumerated and physiologically characterized in three mangrove stations along the Zuari estuary. The substrates for counting were lactate, acetate, propionate, butyrate and benzoate. Benzoate oxidizing SRB were widespread and occurred in numbers up to 6.62 x 10(3)/g dry sediment. The next highest in number were lactate utilizing SRB. On an average there were more propionate and butyrate utilizers than acetate utilizers. While Agasaim at the mouth of the estuary harboured highest number of lactate oxidizers, none were detected at Mirabaug upstream during the samplings. The SRB shared many characteristics with Desulfovibrio desulfuricans, D. desulfuricans aestuarii, D. salexigens, Desulfotomaculum orientis, D.... |
| Tipo: Text |
Palavras-chave: Bactéries; Sulfato-réductrices; Estuaire; Sédiments; Mangrove; Mangrove-Bacteria; Sulfate-reducers; Estuary; Sediments. |
| Ano: 1991 |
URL: http://archimer.ifremer.fr/doc/00323/43395/43103.pdf |
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| Robert, Stephane; Razet, Daniel; Goulletquer, Philippe; Soletchnik, Patrick; Geairon, Philippe; Le Moine, Olivier; Faury, Nicole; Mineur, Frederic; Seugnet, Jean-luc. |
| L'aménagement du fleuve Charente constitue un enjeu particulièrement important tant au niveau des activités de la bande côtière que pour le bassin versant. Au niveau du littoral charentais, et en particulier pour la conchyliculture, le fleuve Charente représente le principal apport d'eaux douces, et donc d 'éléments nutritifs, essentiels au développement de la production primaire et des larves d'huîtres. Ainsi, les apports d'eau douce sont importants pour le développement du phytoplancton (printemps, été, automne), le développement des larves d'huîtres en période estivale qui requiert une dessalure, et la qualité des huîtres en fin d'année. Les suivis des caractéristiques de la Charente sont par conséquent particulièrement importants et ont déjà fait... |
| Tipo: Text |
Palavras-chave: Salinité; Température; Evolution temporelle; Estuaire; Paramètres hydrologiques; Charente; Bassin de Marennes Oléron. |
| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/00072/18363/15935.pdf |
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| Registros recuperados: 36 | |
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