inscription
PORTAIL D'INFORMATION GÉOGRAPHIQUE

Résultats de la recherche (9953 résultats)

Affinez votre recherche

Par Collection Par Auteur Par Date Par Sujet Par Titre Par ville ? Par pays ? Par continent ?
  • Sediment transport in a proglacial valley, Sermilik, East Greenland
  • Climatic variation ; Cold area ; Glacial features ; Greenland ; Hydrology ; Model ; Sediment transport ; Valley
  • Glaciaire ; Groenland ; Hydrologie ; Modèle ; Transport sédimentaire ; Vallée ; Variation climatique ; Zone froide
  • Detailed investigations of sediment transport have been carried out in a proglacial valley at the Mitdluagkat Glacier in East Greenland. The results from 1989, 1990 and 1991 have been compared with earlier measurements of sediment transport
  • . The hydrologic regime will be described and the effect of the development of an icing on the fluvial transport will be discussed.
  • Sustained storage and transport of hydraulic gold mining sediment in the Bear River, California
  • California ; Catchment area;Watershed ; Fluvial processes ; Gold ; Human impact ; Mining activity ; Model ; Pollution ; Sediment transport ; United States
  • Action anthropique ; Bassin-versant ; California ; Etats-Unis ; Exploitation minière ; Fluviatile ; Modèle ; Or ; Pollution ; Transport sédimentaire
  • 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.
  • Differences in hillslope runoff and sediment transport rates within two semi-arid catchments in southeast Spain
  • Erosion ; Lithology ; Murcia ; Precipitation ; Runoff ; Sediment transport ; Semi-arid area ; Spain ; Watershed
  • Bassin-versant ; Domaine semi-aride ; Ecoulement ; Erosion ; Espagne ; Lithologie ; Murcia ; Précipitation ; Transport sédimentaire
  • This paper focuses on hillslope runoff and sediment transport within 2 catchments in southeast Spain. 5 monitoring sites were established on hillslope concavities throughout the 2 catchments. The techniques used were mini-crest stage recorders
  • , spray-painted lines, sediment traps and tipping bucket rain gauges. Sediment transport and depth of runoff varied dramatically with lithology; marl sites produced most runoff and sediment transport.
  • Mechanics of sediment transportation and alluvial stream problems
  • Ecoulement ; Fluviatile ; Géographie physique ; Hydrodynamique ; Sédiment alluvial
  • Suspended sediment in the river Rhine. The impact of climatic change on erosion, transport, and deposition
  • Climatic variation ; Floodplain ; Fluvial erosion ; Netherlands (The) ; Rhine ; Sediment transport ; Stream ; Suspended load
  • Charge en suspension ; Cours d'eau ; Erosion fluviatile ; Pays-Bas ; Plaine d'inondation ; Rhin ; Transport sédimentaire ; Variation climatique
  • The aim of this study was to assess the impact of climatic change on sediment transport in the river Rhine, and on the deposition of suspended sediment on the embanked floodplains in the Netherlands. - (AGD)
  • The impact of rainfall on sediment transport by sheetflow
  • Erosion, transport and deposition processes. Theories and models.
  • Experimentation ; Flow ; Precipitation ; Rainfall simulation ; Sediment transport ; Slope ; Slope gradient ; Soil erosion
  • Ecoulement ; Erosion des sols ; Expérimentation ; Pente de versant ; Précipitation ; Simulation de pluie ; Transport sédimentaire ; Versant
  • Discussion of the results of experiments using simulated rainfall. It is shown that, because film thickness increases, the direct impact of rainfall on sediment transport decreases with slope length.
  • Sediment transport in the drainage area of Ribe Å
  • Carrying capacity ; Catchment area;Watershed ; Denmark ; Drainage network ; Erosion balance;Erosion budget ; Fluvial processes ; Sediment transport ; Soil erosion ; Streams
  • Bassin-versant ; Bilan d'érosion ; Capacité de charge ; Cours d'eau ; Danemark ; Erosion des sols ; Fluviatile ; Réseau de drainage ; Transport sédimentaire
  • The objectives of this paper are to quantify the sediment transport leading to the wetland area, to describe the areal variation of transport rates and sediment sources and to establish a sediment balance for the system. Only general remarks
  • on technical solutions of the sedimentation problem are included.
  • Sediment transportation and deposition by rain-triggered lahars at Merapi Volcano, Central Java, Indonesia
  • Indonesia ; Jawa ; Lahar ; Mudflow ; Precipitation ; Pyroclastic ; Sediment budget ; Sediment transport ; Sedimentology ; Stratigraphy ; Volcanism
  • Bilan sédimentaire ; Coulée boueuse ; Indonésie ; Jawa ; Lahar ; Merapi ; Précipitation ; Pyroclastique ; Stratigraphie ; Sédimentologie ; Transport sédimentaire ; Volcanisme
  • This paper aims to present and to discuss the results of investigations concerning sediment transportation and deposition by lahars including sediment concentration which varies widely over time and space on Merapi's slopes. The results indicate
  • that the sediment load fluctuates during lahar flow, further demonstrating that lahars are transient sediment-water flows with unsteady flow properties.
  • Modelling sediment transport from bare rilled hillslopes by areally averaged transport equations
  • Erosion ; Mathematical model ; Model ; Rill wash ; Sediment transport ; Watershed
  • Bassin-versant ; Erosion ; Modèle ; Modèle mathématique ; Ruissellement ; Transport sédimentaire
  • Treating the dynamics of sediment transport as two-dimensional on interrill-areas and as one-dimensional in rill sections, areally averaged sheet sediment transport (SST) equations are developed. The two-dimensional SST equation is averaged over
  • an individual interrill-area width and then along the interrill-area length to obtain local-scale areally averaged interrill-area sheet sediment transport equation (local-scale areal averaging). Similarly, the cross-sectional-averaged rill sediment transport
  • equation is averaged along an individual rill length to obtain local-scale areally averaged rill sediment transport equation.
  • 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
  • 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
  • is explored in more detail using obsevations of sediment transport from the regulated River North Tyne.
  • Feedbacks between erosion and sediment transport in experimental bedrock channels
  • Experimentation ; Fluvial erosion ; Roughness ; Sediment transport ; Stream ; Stream flow ; Topography ; Turbulence ; United States of America ; Utah
  • Cours d'eau ; Ecoulement fluvial ; Erosion fluviatile ; Etats-Unis ; Expérimentation ; Rugosité ; Topographie ; Transport sédimentaire ; Turbulence ; Utah
  • transported as bedload, a single erosion mechanism (abrasion) and sediment-starved transport conditions. They find that patterns of erosion both create and are sensitive functions of the evolving bed topography because of feedbacks between the turbulent flow
  • field, sediment transport and bottom roughness.
  • To explore the mechanisms of river incision, the AA. conducted laboratory experiments in which the complexities of natural bedrock channels were reduced to a homogenous brittle substrate (sand and cement), a single sediment size primarily
  • Sediment transport across a tidal divide in the Danish Wadden Sea
  • Coastal environment ; Denmark ; Estuary ; Hydrodynamics ; Model ; North Sea ; Sediment transport ; Spatial variation ; Suspended load ; Tidal current ; Tide
  • Charge en suspension ; Courant de marée ; Danemark ; Estuaire ; Hydrodynamique ; Littoral ; Marée ; Mer du Nord ; Modèle ; Transport sédimentaire ; Variation spatiale ; Waddenzee
  • The aim of this study is to examine the spatial and temporal variation of water and sediment transport across a tidal divide in the Danish Wadden Sea. This is exemplified by 2 low-energy and 2 high-energy case studies selected from a 2-month
  • observation period. The sediment transport includes measured suspended transport and calculated sand transport.
  • Determination of the sediment transport in an armoured gravel-bed river
  • Sediment transport dynamics. Special issue
  • Carrying capacity ; Comparative study ; Discharge ; Europe ; Geographical information system ; Gravel ; Methodology ; Meuse ; Sediment load ; Sediment transport ; Stream
  • Capacité de charge ; Charge solide ; Cours d'eau ; Débit ; Etude comparée ; Europe ; Gravier ; Meuse ; Méthodologie ; Système d'information géographique ; Transport sédimentaire
  • For 3 periods of 9, 8 and 17 years sediment transport computations are made with 2 series of relationships between sediment transport (Qb) and discharge (Q) in which the condition of the armour layer is taken into account. These sediment-transport
  • -discharge (Qb/Q) relationships are determined by local bed-load transport in the Common Meuse. The survey data in the Common Meuse were analysed with a geographical information system (GIS) (ARC-INFO) to produce maps of the river-bed level. The subtraction
  • of maps of bed levels in different years results in a map with spatial distributions of erosion and sedimentation.
  • Understanding watershed suspended sediment transport
  • This paper synthesizes a variety of methods adopted in suspended sediment monitoring, estimation and modelling for understanding sediment transport processes and determining the suspended sediment load. Methods for sediment monitoring are described
  • in terms of direct and indirect approaches. Different approaches toward the establishment of a sediment rating curve are examine thoroughly. Techniques of sediment modelling are summarized via depiction of various hydrological and sediment models
  • at the watershed scale. The paper ends with the discussion of future developments in suspended sediment studies at the watershed scale.
  • Land-use effects on erosion, sediment yields, and reservoir sedimentation : a case study in the Lago Loíza basin, Puerto Rico
  • Bassin-versant ; Bilan sédimentaire ; Erosion des sols ; Lac artificiel ; Porto Rico ; Sédimentation ; Transport sédimentaire ; Utilisation du sol
  • Land use ; Puerto Rico ; Reservoir ; Sediment budget ; Sediment transport ; Sedimentation ; Soil erosion ; Watershed
  • use, upland erosion, fluvial sediment transport and storage, and reservoir sedimentation.
  • Sediment storage and yield in an urbanized karst watershed
  • Cave ; Doline ; Karst ; Sediment budget ; Sediment transport ; Tennessee ; United States of America ; Urban area ; Watershed
  • Bassin-versant ; Bilan sédimentaire ; Doline ; Espace urbain ; Etats-Unis ; Grotte ; Karst ; Tennessee ; Transport sédimentaire
  • objectives : to investigate the function (source or sink) of sinkholes with respect to sediment transport; to demonstrate how sinkhole sedimentation rates can be used as an indicator of basin sediment yield from some sinkhole drainage basins; and to determine
  • This paper presents a preliminary assessment of fluvial sediment storage and yield in an urbanized, karst watershed. The AA. aim to identify and quantify the function of caves and sinkholes within the context of a sediment budget with 3 specific
  • the relative contribution of a major cave system to a preliminary sediment budget for a karst watershed.
  • Sediment transport rate-based model for rainfall-induced soil erosion
  • Experimentation ; Mathematical model ; Model ; Overland flow ; Precipitation ; Rainfall simulation ; Sediment transport ; Soil erosion ; Water erosion
  • Ecoulement superficiel ; Erosion des sols ; Erosion hydrique ; Expérimentation ; Modèle ; Modèle mathématique ; Précipitation ; Simulation de pluie ; Transport sédimentaire
  • A one-dimensional mathematical model, termed sediment transport rate-based model, is developed for determining rainfall-induced soil erosion and sediment transport. A series of soil flume experiments under simulated rainfall were conducted
  • to simulate the overland flow and sediment transport and to test the sediment transport rate-based model. The numerically simulated hydrographs, sediment transport rate and concentration distributions are in good agreement with those measured in laboratory
  • experiments, demonstrating the efficacy of the transport rate-based model.
  • Modelling gravel-bed topography from sediment transport
  • Cours d'eau ; Gravier ; Géographie physique ; Géomorphodynamique ; Lit fluvial ; Modélisation ; Profil longitudinal ; Transport sédimentaire
  • Présentation d'un modèle de simulation de la topographie d'un lit de graviers, basé sur la description du transport des sédiments grain par grain.
  • Fluvial sediment transport and deposition following the 1991 eruption of Mount Pinatubo
  • Carrying capacity ; Impact ; Philippines ; Pyroclastic ; Sediment transport ; Volcanic eruption ; Volcanism ; Watershed
  • Bassin-versant ; Capacité de charge ; Eruption volcanique ; Impact ; Philippines ; Pinatubo ; Pyroclastique ; Transport sédimentaire ; Volcanisme
  • 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.
  • The influence of microform bed roughness elements on flow and sediment transport in gravel bed rivers : a reply
  • Carrying capacity ; Flood ; Flow ; Fluvial hydrology ; Fluvial processes ; River bed ; Sediment transport ; Turbulence
  • Capacité de charge ; Crue ; Ecoulement ; Fluviatile ; Hydrologie fluviale ; Lit fluvial ; Transport sédimentaire ; Turbulence
  • The inference that flow and form are dynamically linked is in sympathy with the own conclusions of the AA. that cluster spacing is an equilibrium condition governed by the interplay of flow resistance and sediment transport.