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Par Collection Par Auteur- ROY, A.G. (6)
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- BRADBROOK, K.F. (2)
- CHENG, N. (2)
- CHURCH, M. (2)
- DE SERRES, B. (2)
- FURBISH, D.J. (2)
- GABRIELS, D. (2)
- HAGEN, J.O. (2)
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- Geography of polar regions (2)
- (1886-1974) ; Atlantique ; Atlantique, Nord ; Cyclone ; Dynamique de l'atmosphère ; Géographie physique ; Hémisphère Nord ; Ouragan ; Saison (1)
- Ablation glaciaire ; Bilan glaciaire ; Capacité de charge ; Eau de fonte ; Erosion glaciaire ; Glacier ; Glaciologie ; Suisse ; Valais ; Vitesse d'érosion (1)
- Ablation glaciaire ; Contrainte de cisaillement ; Ecoulement glaciaire ; Glacier ; Glaciologie ; Nouvelle-Zélande ; Photogrammétrie ; South Island ; Thermokarst (1)
- Ablation glaciaire ; Drainage ; Dynamique glaciaire ; Ecoulement glaciaire ; Expérimentation de terrain ; Fluctuation du glacier ; Glacier ; Hydrologie ; Suède (1)
- Abruzzi ; Années 1981-2003 ; Appennino ; Base de données ; Géologie régionale ; Italie ; Risque sismique ; Sismicité ; Tectonique (1)
- Abruzzi ; Appennino ; Data base ; Italy ; Regional geology ; Seismic hazard ; Seismicity ; Tectonics (1)
- Acción antrópica ; Análisis espacial ; Corriente de agua ; Dinámica fluvial ; Geometria hidráulica ; Modelo ; Rumanía ; Sistema de información geográfica ; Tectónica (1)
- Acción antrópica ; Base de datos ; Cambio climático ; China ; Corriente de agua ; Dinámica fluvial ; Geometria hidráulica ; Jiangsu ; Precipitación ; Shandong ; Sistema de información geográfica ; Teledetección (1)
- Acción antrópica ; Capa acuífera ; Italia ; Litoral ; Mar Ioniena ; Radar ; Sicilia ; Sobreexplotación ; Subsidencia ; Teledetección ; Tratamiento de datos (1)
- Acción biógena ; Capacidad de carga ; Carga solida ; Cauce ; Corriente de agua ; Crustáceo ; Ecosistema ; Experimentación ; Inglaterra ; Reino Unido ; Rugosidad ; Transporte sedimentario (1)
- Accumulation éolienne ; Action éolienne ; Antarctique ; Climat polaire ; Dune ; Eolien ; Géographie des régions polaires ; Modelé éolien ; Victoria land ; Victoria valley ; Zone froide (1)
- Acoustic method ; Animal tagging ; Brackish water environment ; Estuaries ; Freshwater environment ; Geographic distribution ; Hydrodynamics ; Individual behavior ; Migratory ; Pisces ; Radiotelemetry ; Rhythm ; Salmo salar ; Salmonidae ; Stream ; Velocity ; Vertebrata (1)
- Action anthropique ; Aménagement hydraulique ; Belgique ; Cours d'eau ; Géographie de l'Europe ; Industrialisation ; Sambre ; Transport sédimentaire (1)
- Action anthropique ; Analyse diachronique ; Analyse spatiale ; Cours d'eau ; Dynamique fluviale ; Géométrie hydraulique ; Modèle ; Prahova ; Roumanie ; Système d'information géographique ; Tectonique (1)
- Action anthropique ; Anhui ; Base de données ; Changement climatique ; Chine ; Cours d'eau ; Dynamique fluviale ; Géométrie hydraulique ; Hebei ; Henan ; Huanghe ; Jiangsu ; Précipitation ; Shandong ; Shanxi ; Système d'information géographique ; Télédétection (1)
- Action anthropique ; Géomorphogenèse ; Géomorphologie appliquée ; Lutte contre l'érosion ; Ravinement ; URSS d'Europe ; Urbanisme ; Vitesse d'érosion ; Volga vallée inférieure ; Volgograd oblast (1)
- Fluid flow and sediment transport processes in geomorphology : innovations, insights, and advances in measurement (3)
- ICAR 6 : Aeolian processes. Special issue (2)
- Response of aeolian processes to global climate change (2)
- Rythmes d'évolution des formes d'accumulation et de creusement en milieux tempérés (2)
- Rythmes d'évolution morphologique depuis l'Holocène en milieux tempérés et froids (2)
- Special issue : Methods of mass balance measurements and modeling (2)
- Tarfala Research Station - 50 years of activity (2)
- The International Polar Year project Kinnvika - Arctic warming and impact research at 80° N (2)
- 1 min in the life of a river : selecting the optimal record length for the measurement of turbulence in fluvial boundary layers (1)
- A 35-year record of solifluction in a maritime periglacial environment (1)
- A comparison of flow intensities in alluvial rivers : characteristics and implications for modelling flow processes (1)
- A comparison of the mass balances and flows of Rabots glaciär and Storglaciären, kebnekaise, northern Sweden (1)
- A computer model along a flow-line of an ice dome: captured ice shelf (1)
- A demonstration of the importance of bedload transport for fluvial bedrock erosion and knickpoint propagation (1)
- A field-based theory for time geography (1)
- A further comparison of glacier velocities measured by radio-echo and survey methods (1)
- A method for estimating the interaction depth of surface soil with simulated rain (1)
- A new expression describing the migration of aeolian dunes (1)
- A new statistical model for threshold friction velocity of sand particle motion (1)
- A new statistical model for threshold friction velocity of sand particle motion
- Aeolian features ; Aeolian transport ; Forecast ; Friction velocity ; Model ; Random process ; Sand ; Threshold ; Wind erosion
- A theoretical formulation of threshold friction velocity of sand particles is established by considering the equilibrium of moment forces acting on an irregular particle following Bagnold's scheme. Owing to the statistical nature
- of the microstructure of soil surface, of the particle shape and of positions in the bed, the threshold friction velocity is random. Based on the probability theory of multi-dimension random variable, the probability of the threshold friction velocity, its mean value
- and standard deviation are calculated. The mean value and standard deviation are fitted as functions of sand particle's diameter. A formula of wet threshold friction velocity is also given.
- Use of the discharge-weighted average velocity in studies of the frictional energy loss of streamflow
- Existing resistance equations are designed, and have been historically used, to estimate discharge from manufactured conduits and streambeds which resemble them. They produce a value for the area-weighted average velocity, which can
- then be multiplied by the cross-sectional area to produce an estimate of discharge. In more recent times, researchers have also begun to study energy loss, a use for which the area-weighted average is inappropriate. The discharge-weighted average velocity
- Velocity characteristics along a small step-pool channel
- control variables bedform type, reach gradient and flow depth. To test the hypothesis that velocity characteristics are related to channel bedform types, ANOVA and ANCOVA tests were performed. The bed-generated turbulence and skin friction of runs appear
- This paper summarizes measurements of velocity along 3 reaches of a small mountain channel with step-pool bedforms. Data analyses focused on characteristics of velocity profiles, and on correlations between velocity characteristics and the potential
- . The most important output is the distribution of the friction velocity over the surface. The simulated wind speeds resemble patterns observed during field experiments. In order to obtain realistic predictions of friction velocity it was essential to include
- Observations are made in two small rivers (the Rulles and the Rouge Eau) differentiated both by the nature of their load and their discharge regime. Shear stresses calculated from friction velocities at the sites where erosion actually occurred
- (or failed to occur despite very high velocities) provide a good explanation of the observed movements.
- The effects of slope and slope position on local and upstream fluid threshold friction velocities
- A computational fluid dynamics (CFD) model is used to simulate a stable wind blowing over slope beds of varying height and coupled with the slope-compensating fluid threshold friction velocity formula. Based on the CFD-based model, quantitative
- Aeolian features ; Environment ; Friction velocity ; Industrial site ; Model ; Numerical model ; Roughness ; Turbulence ; Wind erosion
- The AA. focused on the analysis of the mean wall friction velocity on a surface including roughness elements exposed to a turbulent boundary layer. These roughness elements represent non-erodible particles over an erodible surface
- of the roughness elements) of the friction velocity for several non-uniform distributions of roughness elements was analysed by the equation proposed in the literature and compared to the results obtained with the numerical simulations. This comparison showed very
- relating mass flux to friction speed the AA. will discuss how mass transport relates to the velocity observations and how sensitive the prediction will be to the choice of variables.
- environments. Apart from improving the capacity to determine friction factors for velocity and discharge estimation, the findings have implications in general for the initial motion of gravelly bed material.
- This paper presents field evidence of dust entrainment by direct aerodynamic suspension in the absence of significant saltation. They propose to examine whether saltation was occurring by utilizing actual friction velocity and roughness height
- measurements. Wind velocity data were analysed in conjunction with sediment trap particle size analysis and limited continuous PM 10 measurements from individual events. The data were from high-wind dust storms on the Columbia Plateau of Washington state
- The AA. compare macroturbulent coherent structures (MCS) geometry and organization between ice covered and open channel flow conditions. Velocity profiles were obtained using a Pulse-Coherent Acoustic Doppler Profiler in both open channel and ice
- -covered conditions. A field survey was carried out in early March 2008 in a small meandering reach of the Neigette River, which is part of the catchment system of the Mitis River, Quebec. The friction imposed by the ice cover results in parabolic shaped
- velocity profiles. Reynolds stresses in the streamwise (u) and vertical (v) components of the flow show positive values near the channel bed and negative values near the ice cover, with 2 distinctive boundary layers with specific turbulent signatures
- . Vertically aligned stripes of coherent flow motions were revealed from statistics applied to space-time matrices of flow velocities. In open channel conditions, the macroturbulent structures extended over the entire depth of the flow whereas they were
- over a wide range of slopes and discharge rates. The measurements were used to evaluate flow velocity as a function of slope, discharge and rock cover, and to evaluate soil detachment rates as a function of hydraulic shear stress, stream power
- and hydraulic friction. Experiments were conducted at the Lucky Hills site at Walnut Gulch in southeastern Arizona.
- approaches is developed to describe the dependence of the friction velocity upon roughness frontal area and real exposed cover rate. The new formulation proposed will allow a more accurate evaluation of shear stress partitioning as a function of topographic
- with suspension, saltation and creep as well as PM10 emission was used to validate the Wind Erosion Prediction System (WEPS) erosion submodel. Improvements can be made in modeling efficiency by better specifying the static threshold friction velocity
- is modeled in terms of friction velocity reduction, which is a function of wind speed and direction, distance from the barrier, windbreak height, porosity, width, and orientation. A first application of the model was conducted at a study area
- Aeolian features ; Aeolian transport ; Arid area ; China ; Dune ; Friction velocity ; Gansu ; Grain size distribution ; Mars planet ; Quantitative analysis ; Sand ; Simulation ; Wind speed
- Based on quantitative simulations on the formation and evolution of aeolian dune fields, a semi-analytical equation describing the migration of aeolian sand dunes with respect to dune height, annual wind regime, frictional wind speed, and sand grain
- A series of flume experiments, using loose and water-worked gravel beds of narrowly graded grain sizes that were exposed to 6 h of crayfish activity under low-velocity flows, showed a substantial increase in the number of grains entrained
- by subsequent higher-velocity flows when compared with control runs in which crayfish were never introduced. Crayfish alter the topography of their substrate by constructing pits and mounds, which affect grain protrusion. When walking and foraging, they also
- alter gravel fabric by reorienting and changing the friction angle of surface grains. The increase in entrainment arising from disturbance by crayfish was shown statistically significant, with grain transport nearly twice as great. This study illustrates
- Relative dating of Quaternary deposits based on P-wawe velocities in weathered granitic clasts
- California ; Clast-sound velocity ; Datation ; Etats-Unis ; Formation superficielle ; Géographie physique ; Méthodologie ; Quaternaire
- The technique makes use of a microseismic timer to determine the compressional wave velocity (clast-sound velocity) in each clast of a group chosen from a single deposit. From these data a groupe mean velocity is determined that is proportional
- to the age of the deposit : the youngest deposits having the highest velocities. The clast-sound velocity method can be applied to many unconsolidated bouldery deposits up to approximately one million years old.
- The sizing of particles in terms of terminal velocity : a note on the interpretation of data of GERETY and SLINGERLAND with particles sized in terms of terminal velocity
- Discussion of some data obtained by GERETY and SLINGERLAND (1983) which is based on the hypothesis that classification of samples of aerosols above eroding surfaces should be based on terminal velocities rather than on measures of size
- Flow visualization with an echosounder and velocity measurements with an acoustic Doppler current profiler over areas of flat-bed and sand dunes in the highly-stratified Fraser River estuary, Canada, were used to examine the effect of dunes
- internal in-phase waves develop over each of the larger dunes, with water from the salt-wedge reaching the surface of the estuary. It is showed that bed friction is more important in interfacial mixing over the dunes than over the flat-bed