3 Definitions and Uses of GIS, and 3 Similarities and Differences with Regular Maps

3 Definitions of GIS

Definition #1

"Geographic Information Systems (GIS) is a system of hardware and software used for storage, retrieval, mapping, and analysis of geographic data." 

http://www.nwgis.com/gisdefn.htm

Definition #2

"Like the field of geography, the term Geographic Information System (GIS) is hard to define. It represents the integration of many subject areas. Accordingly there us no absolutely agreed upon definition of a GIS (deMers, 1997). A broadly accepted definition of GIS is the one provided by the National Centre of Geographic Information and Analysis:


a GIS is a system of hardware, software and procedures to facilitate the management, manipulation, analysis, modelling, representation and display of georeferenced data to solve complex problems regarding planning and management of resources (NCGIA, 1990)."

http://www.geom.unimelb.edu.au/gisweb/GISModule/GISTheory.htm

Definition #3

"(Geographic Information System) An information system that deals with spatial information. Often called "mapping software," it links attributes and characteristics of an area to its geographic location. It is used in a variety of applications, including exploration, demographics, dispatching, tracking and map making. Using satellites and aerial photography, the U.S. Geological Survey and other organizations have developed digital maps of most of the world. Unlike paper maps, digital maps can be combined with layers of information."

http://www.yourdictionary.com/computer/gis



3 Examples of GIS Use

Example #1

The US Department of Housing and Urban Development uses GIS as part of an online program to help Internet users locate Empowerment Zones and Renewal Communities.  Users simply type their address, zip code, and state, and the program will display the nearest EZs and RCs.

http://gis.cancer.gov/examples/federal.html

http://egis.hud.gov/egis/

Example #2

The US National Library of Medicine uses GIS as part of an online map called TOXMAP to help Internet users locate Toxic Release Inventory facilities Superfund National Priority sights.  The data comes from the Environmental Protection Agency.  TOXMAP displays all the sights at once, and users simply explore the map.

 http://gis.cancer.gov/examples/federal.html

http://toxmap.nlm.nih.gov/toxmap/main/index.jsp

Example #3

The US National Institute of Justice uses a GIS program called Mapping and Analysis for Public Safety (MAPS).  The NIJ uses this program to develop crime maps, which can show crime trends, allowing users of these maps to find high-crime areas, and adjust resources and policies accordingly.  The NIJ publishes various maps and reports, available online. 

http://gis.cancer.gov/examples/federal.html

http://www.ojp.usdoj.gov/nij/maps/welcome.htm



Similarities between Maps and GIS

-Both maps and GIS represent data spatially.

-Both maps and GIS allow users to see considerable data all at once in an easy-to-understand format.

-Both maps and GIS allow users to analyze the data they contain to make decisions.



Differences between Maps and GIS

-Maps are simply spatial representations of data.  GIS produce maps, yet also stores data in map form as part of the software that produced the map in the first place.

-Not all maps are part of a GIS.  For example, some people can create maps using their own data, without GIS software, though this is becoming less common.

-GIS uses layers of data, which the user can display or hide, creating a custom map.  The GIS user can also zoom in or out of a GIS map.  Regular maps, on the other hand, are not customizable; they are a finished product that do not allow users to display or hide layers or change zoom levels.