Analyzing your Hometown Stream using On-line USGS NWIS Data

Laurel Goodell, Department of Geosciences, Princeton University

Short description of the activity:

Students chose a stream of personal interest, which has at least 30 years of discharge data available from the National Water Information System. The instructor first models a discharge analysis using data for local stream that the class has visited. Then for their streams, students a) describe the typical annual pattern of discharge, b) graph peak annual discharge for the years of record, c) make a flood frequency graph and d) integrate background information into an interpretive analysis of the stream's discharge.

How does this activity lend itself to teaching the methods of geoscience?

This activity first teaches students some specific tools of geoscience research, and then allows them to apply those tools to a problems or questions of interest to them. And note that rather than all students analyzing the same set of data and reproducing an analysis already done by the instructor, students are able to choose and develop their their own research topic - they do science.

For example, over the years of record, a student might note an increase in peak annual discharge for their stream. This could be explained by, say, increased run-off due to urbanization or by an increased level of precipitation. To decide between the two, the student might investigate population growth and precipitation patterns in the area or even check records for other stations to determine whether the discharge increase is a local or regional phenomenon. And if, say, it seems to be a local phenomenon, students might investigate why all stations or streams in an area do not show the same pattern.

Upon addressing those problems or questions, of course, others crop up and it ends up being a very real, open-ended investigation. While students might get close to resolving the original problem or question that they started out with, but not without opening up other areas of investigation that may not have been envisioned at the start of the activity.

Specific Adaptations: How do these help the activity address the methods of geoscience?

I currently use this activity in an intro-level course for non-majors at Princeton University where we have students from all over the country and thus streams of all varieties are analyzed - from large to small, from free-flowing to dammed, from rivers that drain the continent to arroyos that only flow a few times a year. This makes things interesting for everyone involved, and also exposes students to the wide variety of stream behavior.

The activity could be easily modified for upper-level classes by increasing the sophistication of the tools used (e.g. MatLab instead of EXCEL, getting more into probability analysis of various-sized discharge events, or introducing public policy aspects).

It could also be transformed into more of a group project, but having students choose or even assigning them gauging stations in a particular area.

Assessment: How are the methods of geoscience assessed?

It would be interesting to have students propose how their investigation could be expanded or improved. For example, how could they resolve such difficulties as uncertainties or gaps in the data, or what critical information is missing?