Geographic information system technology

Abstract

The power and flexibility of a geographic information system (GIS) comes from two characteristics. It operates with geographically referenced data and it is a computer-based system. Geographic location of natural and cultural features provides a unifying framework so that diverse data sets can be compiled and integrated to discover relationships and generate new information. Like other computer-based data management systems, a GIS allows the user to perform complex analyses. Because maps are the primary source of information for a GIS and maps are frequently used to display the data, a GIS is often referred to as computer mapping. But the strength and utility of a GIS lie as much in its data management capabilities as in its cartographic output. Representing the information in a GIS requires the use of specific data structures. Three common GIS data structures are vector, raster and tabular. Vector systems provide the most accurate boundary locations, while raster systems are better for modeling natural phenomena. Both usually contain links to tabular data.