GEOGRAPHIC INFORMATION SYSTEMS: "Intelligent Mapping For All Situations"

• A System is a group of connected entities and activities which interact for a common purpose
• An Information System is a set of processes, executed on raw data, to produce information which will be useful in decision-making
• An Information System has full range of functions, including observation, measurement, description, explanation, forecasting, decision-making
• A Geographic Information System uses geographically referenced data as well as non-spatial data in a database and includes operations which support querying and spatial analysis
• The connection between the elements of the system is geography, e.g. location, addresses, proximity, connection, interaction - " a geographic footprint"
• In GIS, the most common purposes for creating information from geographic data is in decision-making, for managing the use of resources, transportation, utilities, marketing and retailing, the land, atmosphere, oceans or any spatially distributed entities.
• A GIS enables us to ask "What If?" questions - and to examine the results on maps, charts, tables and reports. We can generate many alternatives to choose from in convenient formats, in a very efficient manner.
• A GIS is "a system of hardware, software and procedures designed to support the capture, management, manipulation, analysis, modeling and display of spatially-referenced data for solving complex planning and management problems"

• Although many other computer programs can use spatial data (e.g. AutoCAD and statistics packages), GIS includes the additional ability to perform spatial operations
• Analysis - overlaying map layers to create new information.
• Creating new insights through the visualization of information

• understanding the world and the human place in it; long tradition in spatial analysis
• provides techniques for conducting spatial analysis and a spatial perspective on research

• concerned with the display of spatial information
• currently the main source of input data for GIS is maps
• long tradition in the design of maps which is an important form of output from GIS
• computer cartography (also called "digital cartography", "automated cartography") provides methods for digital representation and manipulation of cartographic features and methods of visualization

• images from space and the air are major source of geographical data; low cost, consistent update potential
• many image analysis systems contain sophisticated analytical functions; interpreted data from a remote sensing system merged with other GIS data

• advances in computer programming and /graphics provide hardware, software for handling and displaying graphic objects, techniques of scientific visualization
• Database Management Systems (DBMS) contribute methods for representing data in digital form, procedures for system design and handling large volumes of data, particularly access and update
• Artificial Intelligence (AI) uses the computer to make choices based on available data in a way that is seen to emulate human intelligence and decision-making - computer can act as an "expert" in such functions as designing maps, generalizing map features, decision support.

• several branches of mathematics, especially geometry and graph theory, are used in GIS system design and analysis of spatial data
• Topology

• many models built using GIS are statistical in nature, many statistical techniques used for analysis
• understanding issues of error and uncertainty in GIS