Pub. date: 2004 | Online Pub. Date: September 15, 2007 | DOI: 10.4135/9781412952415 | Print ISBN: 9780761926498 | Online ISBN: 9781412952415 | Publisher:SAGE Publications, Inc.About this encyclopedia
Geographic Information System
Margaret Leland Smith
At the most basic level, a geographic information system (GIS) is a collection of digital information about physical features and human activities or events that is linked to a spatial coordinate system and available for analysis. The information (or data) is typically stored in a database and referenced, or linked, by means of a geographic coordinate system of measurements. Selected elements are displayed in computer-generated maps as layers of information about a specific area. A geographic information system in use by a police department would include a database of specific information about crimes and arrests that is linked to spatial data for streets, buildings, and other geographic divisions (police beats and/or precincts) and is accessible to department staff through a computer software interface. As needed, various types of crime, or various areas of a community, may be displayed as maps. Geographic information systems are used to create descriptive displays of ...