Three-dimensional topographic on the foreshore zone of sandy beaches
Cordon littoral ; Erosion marine ; Granulométrie ; Géographie de l'Asie ; Honshu ; Ibaraki préfecture ; Japon ; Littoral ; Modèle ; Niveau marin ; Sable ; Topographie
-dimensional beach model in the foreshore zone on sandy beaches was constructed. - (SGA)
Topographic surveys are carried out to elucidate the characteristics of topographic changes in the foreshore zone of two study sites on the Kashima Coast, Ibaraki Prefecture (Kanto). Three types of topographic change were put in order and a three
Un modèle thermo-mécanique complètement tri-dimensionnel pour la couche de glace de l'Antarctique entier est employé pour simuler la réaction de la couche de glace durant le dernier cycle glaciaire-interglaciaire, en ce qui concerne les conditions
This paper presents data on the detailed structure of three-dimensional mean and turbulent flow for different hydraulic conditions at the confluence of natural rivers with discordant beds. The objectives of the paper are : 1) to describe the three
-dimensional field of flow at a junction of natural channels; 2) to assess the role of changes in bed morphology that occur during transport-effective events on the structure of flow at a confluence; and 3) to examine how the structure of three-dimensional flow
Three-dimensional groundwater flow system in the Imaichi alluvial fan, Tochigi Prefecture, Japan
Cône de déjection ; Deutérium ; Eau souterraine ; Honshū ; Hydrochimie ; Irrigation ; Japon ; Modèle ; Nappe aquifère ; Oxygène 18 ; Qualité de l'eau ; Recharge naturelle ; Saison ; Utilisation du sol
Alluvial cone ; Aquifer ; Deuterium ; Groundwater ; Honshu ; Hydrochemistry ; Irrigation ; Japan ; Land use ; Model ; Natural recharge ; Oxygen 18 ; Season ; Water quality
The objective of this study is to make clear the three-dimensional structure of groudwater flow system and the mixing of recharged waters in the aquifer of the Imaichi alluvial fan wich has a complex geological structure, topography, and land use
Aeolian features ; Aeolian transport ; China ; Comparative study ; Gansu ; Model ; Sand ; Wind
This paper focuses on a key problem in wind-blown sand transport research, the lift-off velocities of sand grains. A three-dimensional grain-bed collision model comprising an impact sand grain, a creeping sand grain and a sustaining grain
and ejected velocities gained by the three-dimensionalmodel are lower than the corresponding ones done by two-dimensionalmodel apart from the horizontal rebound velocity. It also shows the lateral velocity and the lateral angular velocity, as well
is presented. Based on this model, the analytical formulae of sand grains'linear and angular velocities are derived. Comparisons of the results with the results gained by a two-dimensional grain-bed collision model show that all components of both rebound
as the upward angular velocity, cannot be obtained by a two-dimensionalmodel, and cannot be ignored when the impact velocity is high.
Simulated slope development sequences in a three-dimensional context
Downvalley sequences of slope profiles have been inferred to represent temporal sequences. Results from a simulation model are presented which demonstrate that for a slope system in dynamic equilibrium, the downvalley variation in form is best
Prediction of the shape of a shallow failure on a mountain slope: the three-dimensional multi-planar sliding surface method
Japon ; Modèle ; Montagne ; Mouvement de masse ; Précipitation ; Prévision ; Ruissellement ; Versant
Forecast ; Japan ; Mass movement ; Model ; Mountain ; Precipitation ; Rill wash ; Slope
A three-dimensional multi-planar sliding surface method developed from the two-dimensional method is proposed to identify the shape and/or volume of a shallow failure that appears on a mountain slope during heavy rainfall. It was applied
to a digital elevation model to determine the site and form of a critical sliding mass on a mountain slope. The method was applied to an actual mountain slope on which a shallow failure caused by heavy rainfall took place. The most probable unstable mass
calculated by the model was almost the same as that at the failed site.
Carrying capacity ; Confluent ; Hydrodynamics ; Model ; Numerical model ; Roughness ; Stream ; Stream flow ; Turbulence
models improve predictive ability and prediction utility compared to 2D applications. This is achieved through comparing the predictions of both 3D and 2D models with high-quality field data. Identical boundary conditions, obtained from a confluence
within a gravel-bed river system with high relative roughness, are defined for each model.
Transferable parameterization methods for distributed hydrological and agroecological catchment models
Agrosystème ; Allemagne de l'Ouest ; Bassin-versant ; Géographie physique ; Humidité du sol ; Informatique ; Modèle numérique ; Méthodologie ; Prévision ; Réseau de drainage ; Sol ; Sédiment
The application of distributed hydrological and agroecological models requires the knowledge of model parameters, boundary conditions and initial conditions for each element of the three-dimensional finite difference grid in the catchment area under
survey. This paper discusses methods suitable for processing the values of such parameters. The Digital Relief Model can be used to compute the ecologically relevant morphographic parameters, the threedimensional Digital Sediment and Soil Model
Channel geometry ; Confluent ; Model ; Roughness ; Runoff ; Sand ; Sediment load ; Sediment transport ; Stream ; Stream flow ; Sweden
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
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
Drumlin ; Glacial features ; Ireland ; Model ; Moraine ; Numerical model ; Subglacial drainage
as ribbed moraine. However, these investigations have left unanswered the question of whether the theory is capable of producing fully three-dimensional bedforms such as drumlins. The AA. show that, while the three-dimensional calculations show realistic
quasi-three-dimensional features such as dislocations in the ribbing pattern, they do not produce genuine three-dimensional drumlins. The AA. suggest that this inadequacy is due to the treatment of subglacial drainage in the theory as a passive variable
, and thus that the three-dimensional forms may be associated with conditions of sufficient subglacial water flux.
The AA. develop numerical solutions of a theoretical model which has been proposed to explain the formation of subglacial bedforms. The model has been shown to have the capability of producing bedforms in two dimensions, when they may be interpreted
Karst landform development in a three-dimensional theoretical model
Chine ; Dissolution karstique ; Doline ; Guizhou ; Infiltration ; Karst ; Karstification ; Modèle ; North Island ; Nouvelle-Zélande ; Ruissellement ; Tectonique ; Topographie
Carbonate dissolution ; China ; Doline ; Guizhou ; Infiltration ; Karst ; Karstification ; Model ; New Zealand ; North Island ; Rill wash ; Tectonics ; Topography
A three-dimensional process-response model is developed that assesses the minimum requirements for karst landform evolution, the effect of different starting conditions on end-stage landforms, and whether different landform types are the results
of different environments or merely represent successive stages under unchanging conditions. Results of 7 different runs of the model are presented as block diagrams, each run representing a different set of conditions. Variables tested that influence the rate
Alps (The) ; Geographical information system ; Hydrogeology ; Infiltration ; Italy ; Landslide ; Model ; Mountain ; Phreatic ground water ; Precipitation
Within the framework of Geographic Information System (GIS), the distributed three-dimensional groundwater model MODFLOW is applied to evaluate the groundwater processes of the hydrogeological system in the Alverà landslide. The application
of this model has permitted an analysis of the spatial distribution of the structure (DTM and landslide bottom) and the mass transfer elements of the hydrogeological system. The field survey suggested zoning the area on the basis of the recharge, groundwater
A coupling threedimensional baroclinic model of Biwa Lake air-water system
Biwa ; Circulation de l'eau ; Cyclone ; Dynamique de l'atmosphère ; Honshū ; Hydrodynamique ; Japon ; Lac ; Modèle numérique ; Température de l'eau ; Variation saisonnière ; Vent
Atmospheric dynamics ; Cyclone ; Honshu ; Hydrodynamics ; Japan ; Lake ; Numerical model ; Seasonal variation ; Water circulation ; Water temperature ; Wind
A numerical model coupling atmosphere with hydrodynamics is set up in this paper, and is applied in the experimental study of Lake Biwa. Discussion of the results.
Gravel ; Model ; River bed ; Runoff ; Simulation ; Stream ; Stream flow ; Turbulence
This paper presents high-resolution three-dimensional data illustrating the effects of pebble clusters on turbulent flow characteristics in a simulated gravel-bed environment. Past research has tended to focus on only 2 flow components : downstream
) model and will elucidate more explicitely bed-flow interactions in gravel-bed environments.
Essai de mise au point d'un modèle numérique tri-dimensionnel pour la simulation de l'effet hydrodynamique d'obstacle. Deux cas sont distingués suivant le contexte thermique. Les résultats sont en accord assez satisfaisant avec les perturbations