All year long, students from Alexander Dawson School in Lafayette, CO, USA, study the section of Boulder Creek running by their school. For a week in spring, some GLOBE students hike up to snow-capped peaks, then follow the rivers run down the mountains to their school site, closely studying its hydrology.

"Boulder Creek begins in the mountains east of the Continental Divide. It flows down to the city of Boulder and then out to our school. We wanted to see how the water changed along the way," the students write on their web site. "We went to a variety of sites and measured the stream flow, the water chemistry and surveyed the macroinvertebrate species living on the bottom. We also learned about [Geographic Information Systems] GIS mapping and how to use it to present our data."

The project was part of an elective offered to 7th- and 8th-graders that serves as a wider student investigation into the watershed feeding their GLOBE study site. The students send their data to GLOBE, to the Colorado River Watch program and to the city of Boulder. They found that the water chemistry changes dramatically as it moves from the mountains, into town, and on to their school. The types of macro-invertebrate species they observe are also a good indicator of water quality, according to GLOBE teacher Bill Meyers.

"What we see is that the water up in the mountains, starting out with the snow, is practically distilled water, slightly acidic. As it flows down the canyon, the dissolved minerals [make] it more basic. You can see in the mountains the invertebrates are pollution-sensitive," Meyers says. "As we go through the town, they become more pollution-tolerant." Dan Kowal, who works in data management and educational applications at the National Oceanic and Atmospheric Administration (NOAA) and the Cooperative Institute for Research in Environmental Sciences (CIRES) in Boulder, CO, helped the students present their data using GIS.

As you know, GIS software takes the age-old art of making maps and adds the ability to include other important information. In this case, the students mapped out their hydrology measurements and other observations. Besides the water analysis, students had to double-check their global positioning system (GPS) coordinates and latitude and longitude values before making their maps.

"With GIS, all of a sudden you give your data some geographic character, a sense of place and how things are in relation to one another," Kowal says. "The kids were very excited about how their data could be represented, about looking at the map and getting the whole picture. They could see the nature of their graphs changing as theyre moving down from the mountains to the plains."

For more maps, data and information on the Boulder Creek Student Investigation, see the Dawson School web site at http://205.170.81.10/msscience/bcp02/.