FEMA Mapping and Analysis Center

What is a Geographic Information System?

GIS is a database system with software that can analyze and display data using digitized maps and tables for planning and decision-making. A GIS can assemble, store, manipulate, and display geographically referenced data, tying this data to points, lines and areas on a map or in a table. GIS can be used to support decisions that require knowledge about the geographic distribution of people, hospitals, schools, fire stations, roads, weather events, the impact of hazards/disasters, etc. Any location with a known latititude and longitude or other geographic grid system can be a part of a GIS. ¹

GIS is a very useful tool for many aspects of emergency management, including: emergency response, planning, exercises, mitigation, homeland security and national preparedness. In addition to its ability to manage and display data, GIS has robust modeling capabilities, allowing its users to adjust data and scenarios for prediction, planning and estimation.

The current trend in GIS is on web-based mapping. This capability can allow users to view an already created map or create maps, based on their own specifications, on their personal computers. Web-based mapping is expected to widely expand the use of GIS in the workplace, in schools, and in homes.

¹ Lauden, Kenneth C., and Lauden Jane P. 2000. Management Information Systems, 6th Edition, Prentice Hall Publishing Company: Upper Saddle River, NJ