ABSTRACT
A geographic information system (GIS), in a narrow denition, is a computer system for the input, manipulation, storage, and output of digital spatial data. In a more broad denition it is a digital system for the acquisition, management, analysis, and visualization of spatial data for the purposes of planning, administering, and monitoring the natural and socioeconomic environment. It represents a digital model of geography in its widest sense (see Figure 4.1).
