GIS Definitions

Geographical Information System (GIS): - GIS has been defined by many ways, by many people.

One of the way it has been defined is: It is a systematic integration of Computer Hardware, Software and Spatial Data, for capturing, storing, displaying, updating manipulating and analysing, in order to solve complex management problems.

How would I explain GIS to a common man : Previously we had paper maps, which were very colourful, which we couldn't modify. Then came the computer revolution, where the maps were digitised and stored in digital format. These were just entities (line, circle, polygon or point) and it use not give any information, what that entity means in geographical terms. Using these digital files we can only modify easily and reproduce it quickly. We can not use them for any analysis purpose. Then came the GIS, which made these entities intelligent. It attached a value(attribute) to these entities, with what it actually means in geographical terms.

Let me explain you, with well know GIS software ArcInfo and MapInfo. If you notice the software name. In it two words have been combined, i.e. Arc and Info making ArcInfo, Map and Info making MapInfo. Arc / Map meaning the graphical entities and Info meaning attribute. It means Arc having Information and Map having Information, makes them intelligent, which can be used for querying and analysis.

GIS can be used by any business that utilises geographical information.

For example

• exploration and mining companies use GIS information to find out prospective areas for exploration and mining and also to analyse the orebody.

• power companies use GIS to monitor and analyse the electricity load on the grid network for a particular area

• transportation companies use GIS to help determine the best route for delivering there good at less time.

• retail trade companies using GIS to determine the best location for a new outlet.

• GIS data is nowadays also used on the Internet for giving an graphical representation of the users querying.

More GIS Definitions

A definition quoted in William Huxhold's Introduction to Urban Geographic Information Systems. (New York: Oxford University Press, 1991), page 27, from some GIS/LIS '88 proceedings:

". . . The purpose of a traditional GIS is first and foremost spatial analysis. Therefore, capabilities may have limited data capture and cartographic output. Capabilities of analyses typically support decision making for specific projects and/or limited geographic areas. The map data-base characteristics (accuracy, continuity, completeness, etc.) are typically appropriate for small-scale map output. Vector and raster data interfaces may be available. However, topology is usually the sole underlying data structure for spatial analyses."

C. Dana Tomlin's definition, from Geographic Information Systems and Cartographic Modeling (Englewood Cliffs, NJ: Prentice-Hall,1990), page xi:

"A geographic information system is a facility for preparing, presenting, and interpreting facts that pertain to the surface of the earth. This is a broad definition . . . a considerably narrower definition, however, is more often employed. In common parlance, a geographic information system or GIS is a configuration of computer hardware and software specifically designed for the acquisition, maintenance, and use of cartographic data."

From Jeffrey Star and John Estes, in Geographic Information Systems: An Introduction (Englewood Cliffs, NJ: Prentice-Hall, 1990), page 2-3:

"A geographic information system (GIS) is an information system that is designed to work with data referenced by spatial or geographic coordinates. In other words, a GIS is both a database system with specific capabilities for spatially-reference data, as well [as] a set of operations for working with data . . . In a sense, a GIS may be thought of as a higher-order map."

And from Understanding GIS: The ARC/INFO Method (Redlands, CA: Environmental System Research Institute, 1990), page 1.2:

A GIS is "an organized collection of computer hardware, software, geographic data, and personnel designed to efficiently capture, store, update, manipulate, analyze, and display all forms of geographically referenced information."

Source and authors: Kenneth E. Foote and Margaret Lynch, The Geographer's Craft Project, Department of Geography, University of Texas at Austin.

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