GIS: The What and Why

I've found that the most common response to the news that I'll be studying GIS this fall is "What's GIS?" It's a frustrating question for me, since I usually stumble my way through the explanation -- and likely frustrating for the listener too who has to suffer through the stuttering. The problem isn't a poor grasp of the subject matter, but having to decide what definition of a complex topic to choose, how to tailor it to the level of understanding of whoever is asking, how much time I actually want to spend explaining it and how thorough an explanation they really want to hear. On this occasion, no one is explicitly asking the question so I can take the chance to define it and its importance on my own terms, as I understand it.

Almost all data can include an element of location -- address, postal code, geographic coordinates. A geographic information system (GIS) allows us to integrate, manage, analyze and display this geographically referenced information. Depending on the knowledge level and objectives of the user, a GIS can take on many definitions:

• a container of digital maps
• a computerized tool for solving spatial problems
• a digital inventory of geographically distributed facilities and objects, in the case of utilities management, transportation, or resource management
• a tool for visualizing geographic information to reveal patterns or relationships that are otherwise invisible
• a means of performing operations on spatial data that would be too complicated or tedious if performed by hand

What Can It Do?

Geography plays a role in nearly every decision we make: choosing sites for facilities or services, targeting market segments, planning distribution networks, evaluating emergency response routes and providing monitoring during and after an emergency, redrawing political boundaries. All of these problems involve questions of geography, as do countless others. So, as it has been said: "The application of GIS technology is limited only by the imagination of those who use it."

Some concrete examples pulled from this site:

• showing distribution of food banks and shelters in relation to low-income populations to determine whether more services are needed and where
• identifying where recommendations for environmental improvements have been made within a watershed to determine gaps
• development of efficient delivery routes for transportation firms
• plotting climate and land characteristics in order to identify possible locations for lost settlements of the norsemen in North America
• plotting contaminated underwater streams to see if they affect water wells for residents
  
• evaluating emergency response routes and providing ongoing monitoring during and after an emergency (used extensively for recovery effort in Florida during and after Hurricane Andrew in August 1992)

In general, as I see it the importance of GIS is its power to inform better decisions. The ability to integrate vast amounts of different types of data (with location as the unifying element), then visualize, query, and perform analyses on the data, allows the user to see patterns that might otherwise be invisible and predict the outcome of a given decision. This capability -- simulation of a particular decision to assess its effects before actually implementing it -- is and will become more important as we address environmental problems and increasing resource scarcity. Things must be done right the first time around, in the most efficient and least wasteful/harmful manner possible -- be it urban planning, construction, manufacturing, etc. Although counterproductive in a monetary based economy, where it's in the firm's best interest to design a product or service that will soon become obsolete to ensure continued business, we must soon get in the habit of using resources responsibly, doing things perfectly the first time around so they don't need to be redone a few months or years in the future.