An Introduction to Geographic Information Systems
You're planning the family vacation—a cross-country trip from your home in Boston. Along the way, you want to see your cousin Patty in Pittsburgh, brother Billy in Baltimore, Bob Dylan's birthplace in Hibbing, Minnesota, and about twelve other stops along the way to your final destination, Disneyland in Anaheim, California. You fire up your computer, surf to a favorite Web site, tell it your stops and destination, and whammo! Your route is planned for you down to the mile. You might even ask for a list of restaurants in various locations, some scenic turnouts along the highways, and areas to avoid in certain cities.
When most people are asked what Geographic Information Systems (GIS) is, this is the kind of thing they might think of. This is understandable, because GIS technologies have typically been used in "back rooms" for specialized purposes, as additions to business applications or for scientific research, and have only just begun to emerge into the mainstream of IT. GIS will continue to function for these purposes, but advances in computer processing power, the Internet, and Web technologies are making the once specialized information and knowledge available to the public through more and more interesting and diverse applications. MapQuest and Expedia, Web sites that generate trip plans and find restaurants, are fine examples of the proliferation of these applications, but they simply scratch the surface.
Prior to these advances, people asked to describe GIS may not have been able to answer the question at all, or inadvertently confused it with Global Positioning System (GPS), which, although it serves as an important data source for GIS, is not GIS.
For the most part, GIS users up to the very recent past have been required to be technically skilled in several different software packages and the creation and use of several data formats, as well as the results generated from operations on those data. Recently, advances in the same software packages have allowed GIS tools to be built into business applications to serve various groups of people in their day-to-day business. This integration has led to GIS data becoming far more prevalent and transparent than in the past, while the tools and techniques used have become far more accessible to everyday users.
Non–GIS IT professionals will recognize some aspects of GIS, as this branch of IS utilizes some tools in common with other IS technologies, including relational databases such as Oracle or SQL Server, as well as Web servers such as Microsoft's IIS. To deal with the unique nature of spatial data, vendors such as Oracle have developed tools to better manage the spatial information, and others will surely follow.
Geographic Information Systems (GIS) is the branch of information systems technologies that deals with the geographic, or spatial, informational component of an entity or entities in a system. In general, GIS is used to answer the question "Where?" as in "Where is crime highest?" or "Where is the best location for a new power plant, restaurant, gas station, school, etc.?" or "Where should we focus efforts to clean up a river?" The questions are endless. By analyzing the data provided from various sources, users at various organizational levels can make observations, conclusions, and policies, if necessary, to answer these questions.
A popular GIS magazine recently held a contest highlighting some applications of GIS. Two of the top three were related to crime tracking, one of which is available to the public via the Internet. My original intent was to make this article very generic; to show off the many fields in which GIS is currently used, and the many answers to questions like those asked above. However, as an introduction to GIS, I realized it would be better to focus on a single industry or topic, thus keeping the reader on track. As a result, I'll continue to focus on crime-related activities throughout the remainder of this article, to introduce and explain additional concepts.