GIS - Geographical Information Systems

Steven L. Fama - Supervisor of GIS
200 Pleasant St., Room 131
Malden, MA 02148
E-mail: sfama@cityofmalden.org
Telephone: (781) 397-7156
Fax: (781) 388-0613

What is GIS and why we use it

A geographic information system (GIS) integrates hardware, software and data for capturing, managing, analyzing and displaying all forms of geographically referenced information.

Geography Matters

Geography plays a role in nearly every decision we make. Choosing sites, targeting market segments, planning distribution networks, responding to emergencies or redrawing country boundaries—all of these problems involve questions of geography. GIS allows us to view, understand, question, interpret and visualize data in many ways that reveal relationships, patterns and trends in the form of maps, globes, reports and charts. In short, a GIS helps you answer questions and solve problems by looking at your data in a way that is quickly understood and easily shared.

Three Views of GIS

A GIS is most often associated with a map. A map, however, is only one way you can work with geographic data in a GIS and only one type of product generated by a GIS. A GIS can provide a great deal more problem-solving capabilities than using a simple mapping program or adding data to an online mapping tool.

The Database View. A GIS is a unique kind of database of the world—a geographic database (geodatabase). It is an "Information System for Geography." Fundamentally, a GIS is based on a structured database that describes the world in geographic terms.
The Map View. A GIS is a set of intelligent maps and other views that show features and feature relationships on the earth's surface. Maps of the underlying geographic information can be constructed and used as "windows into the database" to support queries, analysis, and editing of the information.
The Model View. These geoprocessing functions take information from existing datasets, apply analytic functions and write results into new derived datasets. By combining data and applying some analytic rules, you can create a model that helps answer the question you have posed.

Together, these three views are critical parts of an intelligent GIS and are used at varying levels in all GIS applications.

Some GIS Tools Used


GIS Desktop	GPS Unit	Plotter