Abstract
A Geographic Information Systems (GIS) is an automated information system that is able to compile, store, retrieve, analyse and display mapped data. Map data used by GIS are collected from existing maps, aerial photos, satellites and other sources. Unlike many other forms of computer graphics, such as computer-aided drafting (CAD) systems, a GIS displays actual geographic or mapped objects. GIS is, however, more than a mapping system. It has the capability to analyse data and to present the results of that analysis as useful information to assist decision makers. Its applications include environmental research and model building, urban demographic studies and transportation analysis. (A)