A GIS (Geographic Information System) is a computer application that can capture, store, analyze, and display geographically referenced information.

Most emergency-related information contains a location reference, placing the information at some point on the globe. The power of a GIS comes from its ability to link, or integrate, pieces of information that are difficult to associate in any other way.

For example, a GIS can combine information from different sources – maps, pre-plans, hydrant records, land records, and aerial photography – to display a road map that includes building information, water sources, topography, and visual images of the area surrounding an emergency. A GIS can analyze this information to provide visual data that includes driving directions, fall-back zones, and hazmat warnings.

GIS-related Information is readily available today, making GEOCommand and other GIS applications more powerful and useful than ever before. Software tools that automatically extract features from satellite images or aerial photographs are replacing what has been a time-consuming data entry process. Data sources – produced by federal, state, and local governments, private companies, academia, or nonprofit organizations – are often free, or they can be purchased or donated.