Components
There are five primary components of a GIS which are
critical to its success:
- Hardware capabilities affect the processing speed, ease of use and the type of output available. A GIS can run on a wide range of hardware types, ranging from desktop computers to large computer servers. Other hardware components include graphics devices, plotters, printers and scanners.
- Software tools provide the functions and tools required to store analyse and display the spatial data. This includes the GIS software, database and drawing software.
- Data is the core of any GIS. There are two types of data used in a GIS - spatial and tabular (also known as attribute data). The availability and accuracy of data will affect the results of any analysis. A GIS can integrate data from a number of different sources and store in a database management system.
- Procedures are the defined methods used to analyse the data and produce accurate results. The procedures include access protocols, standards and guidelines.
- People are responsible for the day-to-day operations of the GIS. Users include technical experts, managers, administrators and end users.
Subsystems of a GIS
A GIS is a computer system which facilitates the phases
of data entry, data management, data manipulation and analysis and data
presentation. This requires an information system that has four main functional
subsystems:
- The data input subsystem allows the user to capture, collect and transform both spatial and tabular (attribute) data into digital form
- The data storage and retrieval subsystem organises the data into a form that allows it to be retrieved by the user for analysis. This usually involves the use of a database management system
- The data and manipulation and analysis subsystem allows the user to define spatial and attribute queries to derive information. The data output subsystem allows the user to generate graphic displays (maps and charts) and tabular reports.