If you look at a map from 30 years ago, and compare it with a map of the same area today, you are likely to see very little undeveloped land.

That's urban sprawl for you. In another thirty years we'll just be one big suburb, with strip malls stretching from coast to coast, or will we?

There are ways to change how suburbs and towns grow so that they don't just spread out of control. For example, Claire Jantz, a geographer at Shippensburg University in Pennsylvania, studies how urban sprawl happens and tries to predict how it will affect the environment in the future.

By using satellite images of the Eastern seaboard, specifically the Washington, D.C.- Baltimore area, to see how land has been developed in the past. Then she feeds that information into a computer model called SLEUTH, which uses the data to help predict how urban sprawl will continue over the next several decades.

If land development continues the way it has, by 2030, urban sprawl in the D.C.- Baltimore area will continue to grow another 80%.

The cool thing about SLEUTH is that it doesn't only predict what will happen. You can also use it to envision alternative futures, like if different land use policies are put in place to cut down on sprawl. Professor Jantz has shown that, with the right planning, urban sprawl could be better regulated in the future.