Organizing Geographic Data

Imagine you are flying from New York to Los Angeles. As the airplane descends over the L.A. basin, you look out the window. How would you describe what you see?

Because you cannot describe all the details of the complex cityscape below, you might break it down into objects: you might describe features such as buildings and streets, events such as a traffic jam, or phenomena such as a rainstorm. To describe the location of features, events, and phenomena, you might use terms such as "in front of" or "next to" or even geographic directions such as "north of the freeway" or "southwest of downtown."

What you did was the first step in creating geographic data. You identified features, events, and phenomena and associated them with a location. In your head, you created a model of the cityscape below you. If you recorded this model by drawing a map, taking a photo, or just writing the information down on a piece of paper, the result would be geographic data.

Geographic data is recorded information about the earth's surface and the objects found on it, associated to a geographic location. In this module, you will learn more about geographic data—how it is organized and stored in a GIS, and how it can be assembled into a useful GIS database.