GEOSCAN, résultats de la recherche


TitreTopological and thematic layering of geological map information: improving efficiency of digital data capture and management
AuteurViljoen, D
SourceProceedings of a workshop on digital mapping techniques: methods for geologic map data capture, management, and publication; par Soller, D R (éd.); United States Geological Survey, Open-file Report 97-269, 1997 p. 15-21
LiensOpen File Report 97-269
Séries alt.Commission géologique du Canada, Contributions aux publications extérieures 12295
ÉditeurUnited States Geological Survey |a US (US)
RéunionDigital Mapping Techniques '97; Lawrence, Kansas; US; juin 2-5, 1997
Documentdossier public
Mediapapier; microfiche; numérique
Sujetsapplications par ordinateur; méthodes analytiques; applications de système d'information géographique; géomathématique
Points de vente
United States Geological Survey (ESIC Open File Reports)
P.O. Box 25286, Denver, CO 80225; Ph. 303-202-4210 [Volume complet (en papier)]
29,25 $
Points de vente
United States Geological Survey (ESIC Open File Reports)
P.O. Box 25286, Denver, CO 80225; Ph. 303-202-4210 [Volume complet (microfiche)]
5,00 $
Résumé(disponible en anglais seulement)
Geological maps are typically complicated documents containing a variety of information that is both spatial and descriptive, such as lithology, structure, mineralogy, topography, and hydrography. This information can be digitally captured, stored, manipulated, and analyzed in a Geographic Information System (GIS). It can be input and stored as points for features at a specific location (e.g. structural observations), lines (chains) for linear features (e.g. faults), and polygons for areal features (e.g. lithological units).
One of the keys to efficient capture and management of geological map data is understanding how polygons are stored in a GIS. Topological and thematic layering are powerful methods that can be utilized to dramatically decrease the amount of time spent capturing, manipulating, analyzing, and managing geological map information. Topological layering involves separating the lines and polygon labels (area points) required to "build" polygons in a GIS from other line and point features. Thematic layering entails separating spatial information by theme (e.g. topography and geology). It is very useful to separate polygon layers thematically. The most dramatic example of this is separating geological (e.g. lithological units) and hydrographic (e.g. lakes) polygons.
There are presently two dominant pathways for digital data capture: digitizing tablet and scan/vectorize. The layering concepts introduced in this paper can be utilized regardless of the data capture pathway and will improve the efficiency of data capture.
This paper will review how polygons are created and stored in a GIS and compare the "single-layer" map oriented approach and "multi-layer" GIS approach to digitally capturing and managing geological map information. It will highlight the advantages of the "multi-layer" approach in terms of data management, analysis, and visualization.