ABSTRACT
A primary difference between a GIS and other types of information systems is the spatial analysis functions of a GIS. Particularly in water resources engineering, there is an emphasis on map-oriented analyses. Beginning with map representations of the land, engineers seek to plan and design facilities that accommodate terrain relief. For example, the terrain governs the layout of a water supply pipeline so that gravity flow conditions dominate, thereby minimizing pumping. Prior to GIS, computations were based on data extracted from maps by hand. With GIS data in digital formats, these computations can now be conducted automatically.
