inscription
Portail d'information géographique

Résultats de la recherche (995 résultats)

Affinez votre recherche

Par Collection Par Auteur Par Date Par Sujet Par Titre
  • Géomatique ; Géomorphologie ; Modèle numérique
  • Geomatics ; Geomorphology ; Numerical model
  • in the fieldwork, utilization of the main GIS functions in the analysis of geographical data and geostatistical methods in the construction of the digital geomorphological model (DGM). The digital geomorphology opens new investigative research fields, which
  • The paper presents the concept of digital geomorphology, situated on the boundary between geomorphology and geomatics. The digital geomorphology is characterized by: utilization of digital terrain data, use of modern measurement technologies
  • Digital terrain models for high mountains in Proceedings of a Symposium on High Mountain Cartography.
  • Alpes ; Autriche ; Cartographie automatique ; Digitalisation ; Glacier ; Généralités sur la géographie ; Modèle numérique ; Montagne ; Technique cartographique ; Tirol
  • The usefulness of portraying the terrain surface from digital data is examined by mapping the Vernagtferner glacier in the Austrian Tyrol. - (DWG)
  • The production of digital elevation models for experimental model landscapes
  • Comparative study ; Digital elevation model ; Experimentation ; Geomorphology ; Model ; Photogrammetry ; Rainfall simulation ; Soil erosion ; Watershed
  • Bassin-versant ; Erosion des sols ; Etude comparée ; Expérimentation ; Géomorphologie ; Modèle ; Modèle numérique de terrain ; Photogrammétrie ; Simulation de pluie
  • Automated digital photogrammetry was used to produce digital elevation models of experimental model landscapes under controlled laboratory conditions as part of a series of rainfall erosion experiments looking at the evolution of landforms
  • in response to erosion. The method allowed the elevations of the experimental landscapes to be studied in great detail on a regular grid digital terrain map. Digital photogrammetry produced elevation data at a resolution of 6 mm with a standard deviation
  • Causes and consequences of error in digital elevation models
  • Bibliography ; Digital elevation model ; Error ; Methodology ; Model ; Physical geography ; Typology
  • Bibliographie ; Erreur ; Géographie physique ; Modèle ; Modèle numérique de terrain ; Méthodologie ; Typologie
  • This paper reviews research on the understanding, modelling and propagation of error in DEMs, with the aim of presenting a comprehensive statement of the issues surrounding these topics : sources of error in DEMs, error models, error propagation
  • The use of digital elevation models in geomorphology
  • Bassin-versant ; Belgique ; Erosion des sols ; Géomorphologie ; Hydrologie ; Modèle ; Modèle numérique ; Pente de versant ; Risque naturel ; Système d'information géographique
  • Belgium ; Geographical information system ; Geomorphology ; Hydrology ; Model ; Natural hazards ; Numerical model ; Slope gradient ; Soil erosion ; Watershed
  • representation of the real land surface. This can be achieved by the use of Digital Elevation models. The power of this tool is demonstrated by some examples in landform description, landform analysis and spatial modelling.
  • The interaction between Geographical Information Systems and geomorphology gains interest, not only because of the more quantitative approach. It is demonstrated in this paper that the main progress is due to the introduction of the digital
  • Methods for the visualization of digital elevation models for landform mapping
  • Cartography ; Comparative study ; Digital elevation model ; Drumlin ; Geomorphological mapping ; Glacial features ; Ireland ; Lineament ; Photogrammetry
  • Cartographie ; Cartographie géomorphologique ; Drumlin ; Etude comparée ; Glaciaire ; Irlande ; Linéament ; Modèle numérique de terrain ; Photogrammétrie
  • Etude comparée de l'utilisation de modèles numériques de terrain pour la cartographie géomorphologique des phénomènes glaciaires en Irlande.
  • The digital elevation model of Italy for geomorphology and structural geology
  • Géomorphologie structurale ; Italie ; Modèle ; Modèle numérique ; Néotectonique ; Pente de versant ; Statistique ; Tectonique
  • Italy ; Model ; Neotectonics ; Numerical model ; Slope gradient ; Statistics ; Structural geomorphology ; Tectonics
  • Three different methods for calculating from a Digital Elevation Model (DEM) slope and aspect are discussed : the Four Contiguous Right Triangles, the Maximum Downward Gradient and the Bicubic Spline First Derivative; the resulting maps have been
  • compared with each other at regional scale and for a small area with a slope map obtained by using classical techniques. The main goal of the comparison has been the choice of the best technique for the computation of the digital slope map of Italy.
  • Main features of geomorphology of the Sudetes re-assessed in the light of digital elevation model
  • Czech Republic ; Digital elevation model ; Geomorphology ; Mountain ; Sudety ; Tectonics
  • Géomorphologie ; Modèle numérique de terrain ; Montagne ; Sudety ; Tchèque république ; Tectonique
  • The Sudetes as a geomorphological region are distinguished by complicated spatial pattern of high- and low-altitude terrains and variable mean slope gradients across the range. An analysis of a digital elevation model and maps derived from the model
  • Suchi chikei moderu no tokeiteki bunseki ni yoru Shikoku jima no chikei tokusei (Caractéristiques du relief dans Shikoku d'après l'analyse statistique selon Digital Terrain Model )
  • Analyse statistique ; Géographie de l'Asie ; Géomorphométrie ; Japon ; Modèle DTM ; Relief ; Shikoku
  • L'analyse statistique à l'aide de Digital Terrain Model permet l'expression quantitative du relief de Shikoku. - (SGA)
  • Digital data acquisition and analysis: an introduction
  • Géomorphologie ; Micro-informatique ; Modèle ; Modèle mathématique ; Technique de recherche
  • Geomorphology ; Mathematical model ; Micro computing ; Model ; Research technique
  • Channel head location and characteristics using digital elevation models
  • Australia ; Digital elevation model ; Drainage network ; Hydrology ; Northern Territory ; Slope gradient ; Spatial distribution ; Watershed
  • Australie ; Bassin-versant ; Distribution spatiale ; Hydrologie ; Modèle numérique de terrain ; Northern Territory ; Pente de versant ; Réseau de drainage
  • extent channel head location can be predicted by the area-slope relationship and the cumulative area distribution. The effect of digital elevation model grid resolution on the ability to locate channel head position and assess hillslope length will also
  • Geomorphometric mapping of Asia Minor from GLOBE digital elevation model
  • Anatolia ; Asia ; Cartography ; Cluster analysis ; Digital elevation model ; Geomorphometry ; Mountain ; Peneplain ; South-Eastern Asia ; Turkey
  • Analyse des groupes ; Anatolie ; Asie ; Asie du Sud-Est ; Cartographie ; Géomorphométrie ; Modèle numérique de terrain ; Montagne ; Pénéplaine ; Turquie
  • This paper focuses on the mapping of landscapes in Asia Minor on the basis of the moderate resolution digital elevation model GLOBE that provides a regional relief representation. Finally, the classification identifies 2 branches. In between
  • Ridge valley line extraction from digital terrain models
  • Généralités sur la géographie ; Image SPOT ; Modèle digital de terrain ; Méthodologie ; Réseau de drainage ; Télédétection
  • Monitoring river-channel change using terrestrial oblique digital imagery and automated digital photogrammetry
  • Alberta ; Braided channel ; Canada ; Channel geometry ; Digital elevation model ; Fluvial dynamics ; Photogrammetry ; Rocky Mountains ; Roughness ; Sediment transport ; Stream ; Stream flow
  • Alberta ; Canada ; Chenal anastomosé ; Cours d'eau ; Dynamique fluviale ; Ecoulement fluvial ; Géométrie hydraulique ; Modèle numérique de terrain ; Photogrammétrie ; Rocky Mountains ; Rugosité ; Transport sédimentaire
  • Imagery acquired using a high-resolution digital camera and ground survey has been used to monitor changes in bed topography and plan form, and to obtain synoptic water-surface and flow-depth information in the braided, gravel-bed Sunwapta River
  • in the Canadian Rockies. Digital images were obtained during daily low flows during the summer meltwater season to maximize the exposed bed area and to map the water surface on the days with the highest flows. The good results allow the AA. to identify other
  • Automated identification of yatsu valleys based on a semantic modeling of landforms using digital elevation models
  • Algorithm ; Classification ; Digital elevation model ; Geomorphology ; Honshu ; Japan ; Modelling ; Slope gradient ; Topography ; Topology ; Valley
  • Algorithme ; Classification ; Géomorphologie ; Honshū ; Japon ; Modèle numérique de terrain ; Modélisation ; Pente de versant ; Topographie ; Topologie ; Vallée
  • The aim of this study is to develop algorithms for identifying Yatsu valleys by topological measurements based on the semantic modeling of landforms using a DEM. Yatsu valleys are valleys with flat floors dissecting into the uplands and hills
  • A comparison of SRTM and high-resolution digital elevation models and their use in catchment geomorphology and hydrology : Australian examples
  • Australia ; Digital elevation model ; Geomorphology ; Hydrology ; Model ; New South Wales ; Northern Territory ; Remote sensing ; Runoff ; Soil erosion ; Soil moisture ; Watershed
  • Australie ; Bassin-versant ; Ecoulement ; Erosion des sols ; Géomorphologie ; Humidité du sol ; Hydrologie ; Modèle ; Modèle numérique de terrain ; New South Wales ; Northern Territory ; Télédétection
  • The AA. examine the Shuttle Radar Topography Mission (STRM) data for 3 catchments in Australia over a range of climates, geology and resultant geomorphology. The SRTM data are compared with high resolution digital elevation models. The AA. use basic
  • hydrology and geomorphology, as in all cases SRTM-derived catchment area is incorrect and smaller digital elevation grid sizes are required for accurate catchment-wide assessment.
  • The topographic data source of digital terrain models as a key element in the accuracy of hydraulic flood modelling
  • Bathymetry ; Catalonia ; Digital elevation model ; Flood ; Gerona ; Global Positioning System ; Model ; Roughness ; Spain ; Stream ; Topography
  • Bathymétrie ; Cataluña ; Cours d'eau ; Crue ; Espagne ; GPS ; Gerona ; Modèle ; Modèle numérique de terrain ; Rugosité ; Topographie
  • The effects of the topographic data source and resolution on the hydraulic modelling of floods were analysed. Seven digital terrain models (DTMs) were generated from three different altimetric sources : a global positioning system (GPS) survey
  • and bathymetry; high-resolution laser altimetry data LiDAR (light detection and ranging); and vectorial cartography (1:5000). Selection criteria were established for the different topographic models in order to assess their generation and treatment in relation
  • to the time-cost ratio for each methodology. the hydraulic modelling was carried out on a 2 km reach of the Ted River near Sant Juliá de Ramis near Girona in NE Spain.
  • Field mapping and digital elevation modelling of submerged and unsubmerged hydraulic jump regions in a bedrock step-pool channel
  • California ; Cartography ; Digital elevation model ; Longitudinal section ; River bed ; Sierra Nevada ; Stream ; Stream flow ; Topography ; United States of America
  • California ; Cartographie ; Cours d'eau ; Ecoulement fluvial ; Etats-Unis ; Lit fluvial ; Modèle numérique de terrain ; Profil longitudinal ; Saut hydraulique ; Sierra Nevada ; Topographie
  • to reducing uncertainty associated with qualitative observations, the data provide the basis for quantitative comparison of different natural jets and jumps with engineered jets and jumps. The digital elevation models highlight the importance of recognizing
  • The aim was to develop a systematic methodology to rapidly survey, digitize and visualize bed and water surface topographies of 2 common types of natural jump regions (submerged and unsubmerged) in a bedrock step-pool channel. In addition
  • Digital elevation modelling in a study of the neotectonic geomorphology of the Sierra Nevada, southern Spain
  • Espagne ; Faille ; Géomorphologie structurale ; Modèle numérique ; Montagne ; Méthodologie ; Néotectonique ; Sierra Nevada ; Statistique
  • Fault ; Methodology ; Mountain ; Neotectonics ; Numerical model ; Sierra Nevada ; Spain ; Statistics ; Structural geomorphology
  • Uplift and erosion creates truncated spurs on fault-controlled mountain slopes. The stepped morphology of these spurs reflects the uplift history of the Sierra Nevada since late Serravallian times. Digital Elevation Models (DEMs) offer a method
  • A comparison of interpolation methods for producing digital elevation models at the field scale
  • Comparative study ; Digital elevation model ; Geographical information system ; Geostatistics ; Interpolation ; Methodology ; Slope gradient ; Topography ; Turkey
  • Etude comparée ; Géostatistiques ; Interpolation ; Modèle numérique de terrain ; Méthodologie ; Pente de versant ; Système d'information géographique ; Topographie ; Turquie
  • of interpolation methods and the nature of errors in digital elevation models obtained with indirect survey methods for small-scale areas. The purpose of this study was therefore to investigate the size and spatial patterning of errors in digital elevation models
  • obtained with direct survey methods for large-scale areas, comparing Inverse Distance Weighting, Radial Basis Functions and Kriging interpolation methods to generate digital elevation models. This study is important because it shows how the accuracy
  • of the digital elevation model is related to data density and the interpolation algorithm used. Cross validation, split sample and jack-knifing validation methods were used to evaluate the errors. Global and local spatial auto-correlation indices were then used
  • to examine the error clustering. Finally, slope and curvature parameters of the area were modelled depending on the error residuals using ordinary least regression analyses. In this case, the best results were obtained using the thin plate spline algorithm.