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	Provedor de dados ArchiMer (3) Autor Deloffre, J (3) Lafite, R (3) Verney, Romaric (3) Brun Cottan, J (1) Brun Cottan, J.-c. (1) Cundy, A (1) Lesourd, S (1) Lesueur, P (1) Taylor, J (1) Mais... Palavra-chave Intertidal mudflat (2) Altimeter (1) Bed erosion (1) Bed roughness length (1) Boat waves (1) Bottom shear stress (1) Macrotidal estuary (1) Morphology (1) Mud (1) Neap spring conditions (1) Rhythmites (1) Seine Estuary (1) Seine estuary (France) (1) Shear stress (1) Spatial variability (1) Tidal currents (1) Wind waves (1) X ray imagery (1) Mais... Tipo do documento Text (3) Ano 2007 (2) 2006 (1) País France (3) Idioma Inglês (3)		Ordenar por:  Relevância Autor Título Ano Registros recuperados: 3 Primeira ... 1 ... Última Sedimentation on intertidal mudflats in the lower part of macrotidal estuaries: Sedimentation rhythms and their preservation ArchiMer Deloffre, J; Verney, Romaric; Lafite, R; Lesueur, P; Lesourd, S; Cundy, A. The objective of this study is to propose an original approach to the analysis of the formation of intertidal rhythmites, their preservation, and the evaluation of sedimentation rates on estuarine mudflats. Three mudflats, one from each of three estuaries, were analysed using a combination of long-term (>a year), high-frequency (1 burst/10 or 20 min), and high-resolution (0.2 cm) altimeter datasets and X-ray images of sediment cores collected during topographic surveys. The results highlight the roles played by sediment supply, hydrodynamics, and morphology of the lower estuaries on the sedimentation rhythms. While the sediment-starved Medway estuary (Kent, UK) remains stable at different time-scales, the annual sedimentation rates on the sheltered... Tipo: Text Palavras-chave: Macrotidal estuary; X ray imagery; Altimeter; Rhythmites; Mud; Morphology. Ano: 2007 URL: http://archimer.ifremer.fr/doc/2007/publication-3517.pdf Tidally-induced shear stress variability above intertidal mudflats in the macrotidal Seine estuary ArchiMer Verney, Romaric; Brun Cottan, J; Lafite, R; Deloffre, J; Taylor, J. Tidal currents and the spatial variability of tidally-induced shear stress were studied during a tidal cycle on four intertidal mudflats from the fluvial to the marine part of the Seine estuary. Measurements were carried out during low water discharge (< 400 m(3) s(-1)) in neap and spring tide conditions. Turbulent kinetic energy, covariance, and logarithmic profile methods were used and compared for the determination of shear stress. The c(TKE) coefficient value of 0.19 cited in the literature was confirmed. Shear stress values were shown to decrease above mudflats from the mouth to the fluivial part of the estuary due to dissipation of the tidal energy, from 1 to 0.2 N m-(2) for spring tides and 0.8 to 0.05 N m(-2) for neap tides. Flood currents... Tipo: Text Palavras-chave: Seine estuary (France); Spatial variability; Neap spring conditions; Intertidal mudflat; Shear stress; Tidal currents. Ano: 2006 URL: http://archimer.ifremer.fr/doc/2006/publication-1887.pdf The effect of wave-induced turbulence on intertidal mudflats: Impact of boat traffic and wind ArchiMer Verney, Romaric; Deloffre, J; Brun Cottan, J.-c.; Lafite, R. Semi-diurnal and fortnightly surveys were carried out to quantify the effects of wind- and navigation-induced high-energy events on bed sediments above intertidal mudflats. The mudflats are located in the upper fluvial part (Oissel mudflat) and at the mouth (Vasiere Nord mudflat) of the macrotidal Seine estuary. Instantaneous flow velocities and mudflat bed elevation were measured at a high frequency and high resolution with an acoustic doppler velocimeter (ADV) and an ALTUS altimeter, respectively. Suspended particulate matter concentrations were estimated by calibrating the ADV acoustic backscattered intensity with bed sediments collected at the study sites. Turbulent bed shear stress values were estimated by the turbulent kinetic energy method, using... Tipo: Text Palavras-chave: Seine Estuary; Intertidal mudflat; Bed erosion; Bed roughness length; Bottom shear stress; Boat waves; Wind waves. Ano: 2007 URL: http://archimer.ifremer.fr/doc/2007/publication-2552.pdf Registros recuperados: 3 Primeira ... 1 ... Última

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