Geographical information systems (GIS)

Geographical information system, also called geobased information system (GIS), is a relatively new technology. It is a very powerful tool for processing, analysing and integrating spatial data sets (Aronoff, 1989; Star and Estes, 1990; Maguire et al., 1991; Attenucci et al., 1991; Heywood et al., 1997). A GIS deals with information on locational patterns of features and their attributes (characteristics). It can be considered as a higher-order computer-coded map which permits storage, selective dedicated manipulation, display and output of spatial information. Figure 6.1 explains the working concept of a GIS; in a very comprehensive sense, GIS may mean identifying data needs, acquiring data, data management, processing and analysis of data and decision-making. In normal usage, however, GIS means spatial data processing, integration and analysis.