2003 Volume 76 Issue 10 Pages 687-702
Geographic information systems (GIS) were developed in the 1960s and 1970s, primarily in the public and academic sectors. In the 1980s, the GIS industry developed under governmental leadership and grew by about 20% each year. The Federal Geographic Data Committee in the U. S. was organized in 1990 under Office of Management and Budget Circular A-16 as the interagency coordinating body for the promotion of sharing, use, and dissemination of the National Spatial Data Infrastructure. The maturing of the GIS industry supported by Federal and state governments and the development of “geographic information science” surrounding the technology have had a major influence on our society and the methodological framework for geographical research.
This GIS revolution of the early 1990s allowed us to develop new ways of understanding the real world and new technologies such as virtual reality using GIS. GIS has also had a major influence on the discipline of geography. The purpose of this paper is to describe some issues concerning the nature of the GIS influence on geographical methodology.
The first issue is the concept of a scaleless GIS database. This means that the database, unlike a paper map, has no apparent scale and is limited by the unique precision of the digitized original data. The second issue concerns the geospatial data model of the real world. Geographic information is extremely complex and not captured well by the commonly used vector and raster data models in GIS. An object-oriented and feature-based approach provides better strategies for modeling the real world as close to a user's perspective as possible. A fundamental unit of the Geographic Information Standard in ISO/TC211 is called a feature. A Geographic Information Standard provides a standard framework for the classification of features in the real world. Figure 1 shows the modeling process from the universe of discourse to the geographic dataset using UML. A feature catalogue means a dictionary of feature types. This methodology of geospatial modeling is based on the concepts of the general feature model (GFM). The GFM is a model based on an object-oriented approach and is similar to the chorographic model of traditional geography. Feature-based GIS provides a new methodology for geography under the traditional chorographic conceptualization of the real world.
