inscription
Portail d'information géographique

Résultats de la recherche (9962 résultats)

Affinez votre recherche

Par Collection Par Auteur Par Date Par Sujet Par Titre Par ville ? Par pays ? Par continent ?
  • Bed-material transport estimated from channel surveys: Vedder River, British Columbia
  • British Columbia ; Canada ; Capacité de charge ; Cours d'eau ; Débit de pointe ; Fluviatile ; Géométrie hydraulique ; Méthodologie ; Transport sédimentaire
  • British Columbia ; Canada ; Carrying capacity ; Channel geometry ; Extreme discharge ; Fluvial processes ; Methodology ; Sediment transport ; Stream
  • This study investigates the possibility to estimate bed-material bed-material transport by analysis of morphological changes along a river channel, by assessment of erosion and deposition in Vedder River, British Columbia.
  • Gravel transport and morphological change in braided Sunwapta River, Alberta, Canada
  • Alberta ; Braided stream ; Canada ; Carrying capacity ; Channel geometry ; Fluvial erosion ; Fluvial processes ; River bed ; Sediment budget ; Sediment transport
  • Alberta ; Bilan sédimentaire ; Canada ; Capacité de charge ; Erosion fluviatile ; Fluviatile ; Géométrie hydraulique ; Lit anastomosé ; Lit fluvial ; Transport sédimentaire
  • The relation between morphological change and patterns of variation in bedload transport rate in braided streams was observed by repeated, daily topographic surveys over a 25 day study period in a 60 m reach of the proglacial Sunwapta River, Alberta
  • The influence of microform bed roughness elements on flow and sediment transport in gravel bed rivers : comment on a paper by Marwan A. Hassan and Ian Reid
  • Capacité de charge ; Ecoulement ; Fluviatile ; Hydrologie fluviale ; Transport sédimentaire ; Turbulence
  • Carrying capacity ; Flow ; Fluvial hydrology ; Fluvial processes ; Sediment transport ; Turbulence
  • The purpose of this discussion is two-fold : 1) to provide a further demonstration of the importance of treating the bedform-flow resistance-sediment transport system in a gravel-bed river as a dynamic interaction, as has been the case for many
  • years in the context of sand-bed rivers; and 2) to emphasize the importance of understanding this interaction and the feedback that controls it in terms of the characteristics of near-bed turbulence.
  • Fluvial sediment transport and deposition following the 1991 eruption of Mount Pinatubo
  • Bassin-versant ; Capacité de charge ; Eruption volcanique ; Impact ; Philippines ; Pinatubo ; Pyroclastique ; Transport sédimentaire ; Volcanisme
  • Carrying capacity ; Impact ; Philippines ; Pyroclastic ; Sediment transport ; Volcanic eruption ; Volcanism ; Watershed
  • The AA. report observations of the magnitude, processes, and effects of fluvial sediment transport and deposition on the Pasig-Potrero River alluvial fan 6 years after the cataclysmic eruption of Mount Pinatubo. This analysis shows bedload transport
  • in volcanically disturbed rivers reflects higher transport capacities than in their nondisturbed counterparts, and that arid zone channels provide a better analog for predicting post-eruption bedload transport due to their high transport efficiency.
  • Three-dimensional flow modelling and sediment transport in the River Klarälven
  • Charge solide ; Confluence ; Cours d'eau ; Ecoulement ; Ecoulement fluvial ; Ecoulement secondaire ; Géométrie hydraulique ; Modèle ; Rugosité ; Sable ; Suède ; Transport sédimentaire
  • Channel geometry ; Confluent ; Model ; Roughness ; Runoff ; Sand ; Sediment load ; Sediment transport ; Stream ; Stream flow ; Sweden
  • and to investigate the short-term sediment transport patterns in the river. The numerical models were built and verified using extensive field data. Based on model outputs, observations are made about the velocity vectors and the secondary flow patterns. The main
  • sediment transport patterns in the river were also investigated by solving the sediment continuity equation for the total sediment load.
  • A three-dimensional flow model that uses the RNG turbulence model and a non-equilibrium wall function was applied to the River Klarälven in the southwest part of Sweden. The objectives were to study the nature of the flow in the river bifurcation
  • Lateral sediment transport by bedforms in a meander bend
  • Carrying capacity ; Denmark ; Earth surface processes ; Fluvial processes ; Jylland ; River bed ; Sediment transport ; Sedimentary structure
  • Capacité de charge ; Danemark ; Fluviatile ; Géomorphodynamique ; Jylland ; Lit fluvial ; Structure sédimentaire ; Transport sédimentaire
  • A case study has been carried out in the Danish river Gels Å in a bend with equilibrium point bar topography. The purpose is to map primary and secondary bedforms and bedform migration in a meander, and to measure the actual rate of the lateral
  • (lateral = perpendicular to the mean flow direction) transport in the bend.
  • Variability of bedload transport and channel morphology in a braided river hydraulic model
  • Carrying capacity ; Channel geometry ; Fluvial processes ; Meander ; Model ; River bed ; Stream
  • The objectives of this paper are: 1) to assess variability in bedload transport and channel morphology in a 1:50 hydraulic model of a braided river under replicate runs, where all the controlling variables are held constant; 2) to investigate
  • the replicability of experimental results; and 3) to determine the extent to which river morphology is a single-valued response to a particular set of controlling variables.
  • The load of organic carbon, nitrogen and phosphorus from two large drainage basins (River Kitka and River Oulanka) in NE Finland
  • The aim of this paper is to quantify the load of organic carbon, nitrogen and phosphorus from 2 large catchment areas, the River Kitka and the River Oulanka, and the transport of the nutrients into Lake Paanajärvi, a deep oligotrophic lake in NW
  • Russian Karelia. In both areas the annual leaching and transport of nutrients were highly dependent on the hydrological conditions.
  • Changes in the hydrology and sediment transport produced by large dams on the lower Ebro river and its estuary
  • Aménagement hydraulique ; Cours d'eau ; Ebro ; Espagne ; Estuaire ; Hydrologie fluviale ; Tarragona ; Transport sédimentaire ; Utilisation de l'eau ; Variation saisonnière
  • Ebro ; Estuary ; Fluvial hydrology ; Hydraulic works ; Seasonal variation ; Sediment transport ; Spain ; Stream ; Tarragona ; Water use
  • The aim of this paper is to analyse the changes in the hydrology and sediment transport in the lower Ebro river and its estuary as a consequence of dam construction and increased water uses in the basin. Changes at different time-scales
  • are specifically considered : long-term changes (years to decades), seasonal changes and daily changes. A critical analysis of the existing data on sediment transport in the present century is also presented.
  • Hillslopes, rivers, plows, and trucks : mass transport on Earth's surface by natural and technological processes
  • Action anthropique ; Cours d'eau ; Géomorphodynamique ; Mouvement de masse ; Technologie ; Transport sédimentaire ; Versant
  • Earth surface processes ; Human impact ; Mass movement ; Sediment transport ; Slope ; Stream ; Technology
  • Acción antrópica ; Corriente de agua ; Geomorfodinámica ; Movimiento de masa ; Tecnología ; Transporte sedimentario ; Vertiente
  • Most of the world's mass-action is generated by the motion of fluids of global or continental extent, as in atmospheric circulation or river flow. Technological mass-action exceeds that of all land-based geomorphic systems except rivers
  • . Technological systems with large mass-action tend to be comprised of discrete, self-powered units (e.g. trucks). Discretization of transported mass reflects the different locomotion strategy required for transport of solids on land, compared with the transport
  • requirements of spatially extensive fluids in nature. The principle of maximum entropy production may provide a framework for understanding the emergence of advective, technological mass-transport systems.
  • Déplacement du trafic dans des corridors de transport à longue distance fortement congestionnés
  • Stratégies pour des transports compatibles avec l'espace et l'environnement
  • Freight ; Germany ; Long-distance traffic ; Passengers ; Rail transport ; River transport ; Road transport ; Territorial planning ; Traffic ; Transport
  • Allemagne ; Aménagement du territoire ; Fret ; Mode de transport ; Passagers ; Trafic ; Transport ; Transport ferroviaire ; Transport fluvial ; Transport routier
  • The study analyses potential shifts in long-distance traffic volumes (passengers and freight transport) in highly congested corridors from road to rail or inland waterways under consideration of capacity restraints on railways. - (MT)
  • Estimated transport of the suspended load of the River Malewa, Kenya, between 1931-1959
  • Action anthropique ; Analyse de régression ; Bassin-versant ; Capacité de charge ; Charge en suspension ; Cours d'eau ; Débit ; Erosion des sols ; Géographie physique ; Hydrologie fluviale ; Kenya ; Malewa ; Modèle ; Transport sédimentaire
  • The aim of this study is to evaluate the usefulness of a data set of the suspended sediment concentration in the River Malewa, Kenya. One important benefit of such an evaluation is to acquire fundamental knowledge about the transport characteristics
  • of this river, so that future management practices to decrease soil erosion are possible to evaluate. The A. uses regression models.
  • Active width of gravel-bed braided rivers
  • Alberta ; Canada ; Chenal anastomosé ; Cours d'eau ; Etude comparée ; Géométrie hydraulique ; Modèle ; Transport sédimentaire
  • Alberta ; Braided channel ; Canada ; Channel geometry ; Comparative study ; Model ; Sediment transport ; Stream
  • Albertá ; Canada ; Canal anastomosado ; Corriente de agua ; Estudio comparativo ; Geometria hidráulica ; Modelo ; Transporte sedimentario
  • model computations of instantaneous active width and observation of time-integrated morphological active width. Understanding these differences can give insight into the nature of bedload transport in braided rivers and the relationship to morphological
  • The AA. compare theoretical predictions of active width in gravel-bed braided rivers with observations from Sunwapta River, (Alberta, Canada), and from a generic physical model of gravel braided rivers, to describe and measure trends and variability
  • in active width. From these empirical results, the AA. formulate a general relation that predicts active width over a range of braided river types and flow conditions. This paper also raises questions about differences between hydraulically-based numerical
  • Les ports et les transports maritimes
  • Coastal environment ; Harbour ; River port ; Sea transport ; Transport
  • Littoral ; Port ; Port maritime ; Transport ; Transport maritime
  • Travail de synthèse axé sur les aspects littoraux du transport maritime : ports et façades, types de circulation maritime et flux de marchandises, flottes et construction navale. - (FC)
  • Generation, transport and deposition of suspended and dissolved material. Examples from Swedish rivers
  • Action anthropique ; Bassin-versant ; Charge en suspension ; Erosion des sols ; Géographie physique ; Hydrologie ; Suède ; Transport sédimentaire
  • The aim of this paper is to give examples of erosion studies made in Sweden on different scales in order to bring into focus the role of sediment transport in Swedish rivers and to form a background for future studies of pollution. Two main sources
  • of data have been used in the analyses : 1) a study in small plots and basins in the Verkaa research basin, about 35 km north of Stockholm, and 2) the nationwide network for the measurement of transport of sediment and dissolved material.
  • Coarse bedload transport in a mountain river
  • transport events associated with the daily rise and fall in stream discharge were investigated. This paper reports the results of this study designed to describe fully the adjustment of river bed and turbulent flow to the unsteady passage of a pebble bedload.
  • Coarse bedload transport dynamics are investigated utilizing hydrodynamic and sediment transport data obtained in an extensively instrumented study reach located in Sqaw Creek, Montana, USA. During 1991 and 1992, a number of discrete bedload
  • A dunai folyami aruszallitas foldrajzi kapcsolatai és annak magyar vonatkozasai. (Geographical aspects of the transportation of goods on the Danube river and related Hungarian problems)
  • Danube ; Danube-Main-Rhin ; Europe ; Europe centrale ; Géographie de l'Europe ; Hongrie ; Infrastructure déficiente ; Prévision ; Réseau fluvial projeté ; Transport ; Transport fluvial
  • The paper consisting of two parts wishes to point out by citing numerous examples that the transportation of goods on the rivers in the Danubian Basin due to the lack of infrastructural services, lags far behind the Main and the Rhein. Within a few
  • Sustained storage and transport of hydraulic gold mining sediment in the Bear River, California
  • Action anthropique ; Bassin-versant ; California ; Etats-Unis ; Exploitation minière ; Fluviatile ; Modèle ; Or ; Pollution ; Transport sédimentaire
  • California ; Catchment area;Watershed ; Fluvial processes ; Gold ; Human impact ; Mining activity ; Model ; Pollution ; Sediment transport ; United States
  • This study examines the large deposits of hydraulic gold mining sediment and reevaluates Gilbert's (1917) classic model of sediment transport in a symmetrical wave that is based on hydraulic mining sediment primarily in the Yuba Basin. Sustained
  • storage and transport of hydraulic mining sediment in the Bear Basin are documented and a revised model of sediment transport is proposed.
  • Sediment transport processes in pool-riffle sequences
  • Carrying capacity ; Channel geometry ; England ; Flood ; Fluvial processes ; Grain size distribution ; Hydrodynamics ; Northumberland ; River bed ; Sediment transport ; Sedimentary structure ; Stream ; Threshold ; Tracer ; United Kingdom
  • Capacité de charge ; Cours d'eau ; Crue ; England ; Fluviatile ; Granulométrie ; Géométrie hydraulique ; Hydrodynamique ; Lit fluvial ; Northumberland ; Royaume-Uni ; Seuil ; Structure sédimentaire ; Traceur ; Transport sédimentaire
  • is explored in more detail using obsevations of sediment transport from the regulated River North Tyne.
  • This paper reviews the published data for sediment transport in pool-riffle sequences which suggests that a velocity or shear stress reversal hypothesis does not explain all of the published evidence of sediment transport. This conclusion
  • Quelques bruits caractéristiques de l'infrastructure de transport dans la vallée de la Tisza
  • Chemin de fer ; Fret ; Géographie des transports ; Hongrie ; Infrastructure ; Passagers ; Route ; Tisza ; Transport
  • Freight ; Hungary ; Infrastructure ; Passengers ; Railway ; Road ; Transport ; Transportation geography
  • The first part of the article describes Tisza River valley as part and a special region of the Great Hungarian Plain. The physical geographical and economic processes shaping the transport network and the changing importance of the Tisza River
  • are highlighted. The second part of the paper investigates the characteristics of different branches of transport (road, railway etc.) in the area, and finally the structure of freight and passenger traffic are analysed. - (JS)