Quantifying Our Stream: A Field Lab on Stream Channel Morphology and Stream Discharge

Emanuela Agosta, Shoreline Community College
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Summary

In this field and lab activity, students will engage in field data collection and in lab data analysis and interpretation of stream dynamics at a local watershed. Data collection will include stream channel morphology, stream velocity, and fluvial landforms. Students will analyze and interpret field data to calculate stream discharge. They will also interpret their field observations within the broader context of the entire watershed, analyzing the human and natural factors affecting discharge, erosion and flooding and considering sustainable stream management options for urban watersheds conservation and restoration.

This activity can be used as a stand-alone lab but in my courses is part of a larger scope field study of a local watershed. This is a service-learning project offering students "hands on" learning opportunities on stream systems while also providing stream monitoring data to city water managers and the public. Real data collected by students in a face-to-face geology course can be also used in online or hybrid classes by students engaged in a virtual stream dynamics lab.

Learning Goals

This field and lab activity will offer students the following learning opportunities:

Geoscience learning goals:

- Engage in "hands-on" and "deep learning" on stream systems including stream channel morphology, stream velocity and discharge variations and other fluvial geomorphic changes (erosion, deposition, flooding, channel migration, mass wasting).

Sustainability learning goals:

- Recognize the impact of human development on stream and slope dynamics in the watershed.

- Investigate sustainable stream management options for urban stream restoration and conservation.

- Engage in place-based learning at a local watershed (the college campus and some of the students' own residences are within the watershed).

Service-Learning goals:

This activity will also partly contribute to a larger-scope service-learning project consisting in:

- Compiling a set of systematic and long-term observations on stream channel morphology, discharge, erosion, flooding and slope stability at a local stream for use by local governments for long-term planning and maintenance.

Context for Use

This activity can be used in college-level introductory geology courses in which running water is an important component of the course. This activity would work best if students are already familiar with river systems and stream dynamics.

This activity can be used as a stand-alone lab, but in my geology courses, it is part of a broader field project centered on a local watershed. Before this lab students will have become familiar with the following resources about the (Boeing Creek) watershed:

River systems: Channel patterns, channel migration, erosion, deposition, flooding and mass wasting in stream systems (in textbook and other lectures).

Orientation on the Stream Monitoring Service-Learning Project:Goals, learning objectives, field observation and methods. (Assignment packet and related PowerPoint presentation is available, upon request)

History and Urban Development within the (Boeing Creek) Watershed: History of the (Boeing Creek) watershed and current urban development in the watershed (in PowerPoint presentation; also including maps of the watershed and Google Earth images); other suggested sources could be "Stream Stats" http://water.usgs.gov/osw/streamstats/Washington.html] or GIS data).

History of flooding in Boeing Creek watershed and human modifications in the watershed (City of Shoreline) and within the Boeing Creek Park.

Underlying Geology:Glacial history of Puget Sound lowland, surface geology and stratigraphy in the Boeing Creek watershed (in PowerPoint presentation)

This activity can be adapted to a different local watershed; it can be used as a field and lab combination (as I do) or just as in-class lab if data on stream discharge can be taken from other sources.

If data on stream discharge are to be collected by students in a field lab session, special equipment will be required. This equipment is listed in the materials check-list included in the "Activity Description and Teaching Materials" section.

This activity can also be adapted for use in virtual field labs in online or hybrid geology courses. Real data collected by students in face-to-face courses could be made available to online students for analysis and calculation of stream discharge. This type of adaptation (which I hope to ultimately do) would require extensive web-developing in converting the entire process of data acquisition and measurement into an online activity. A similar application on fictitious data already exists online in the "Virtual River Lab" (see url in "References and Resources").

Description and Teaching Materials

In attached file Stream Discharge - Activity Description and Teaching Materials (Microsoft Word 2007 (.docx) 27kB Aug27 11)

Teaching Notes and Tips

Safety guidelines:

A word of caution should be spent about choosing the cross-sections at your local stream! Make sure the water depth is less than 3 feet. At Boeing Creek I only choose sections where depth is around 1-2 feet. It makes is a lot easier and safer to go across and stand in the water for the depth and velocity measurements. Do not do the field measurements in a day the stream is flooding! I would also make sure that the students who are doing the measurements in the stream are very comfortable with this and are well-equipped with waders or rain-boots. There are usually 2-3 students who are eager to do this.

If sharing a flow-meter among different student teams, have students work on stream channel observations, sketch and photos (questions 1 and 2) while they wait for instrument to become available.

Warn students about never trespassing into private properties and always engaging in respectful and civil behavior with property owners of adjacent properties.

Remind students about civil and respectful behavior in public spaces, packing their trash and minimizing their footprint and human erosion.

Areas that deserve attention/reinforcement:

In the field part, the most important part is setting up and operating the flow-meter correctly. Spend extra time teaching that and making sure students understand it.

Also, make sure that in the excitement and anticipation of the stream measurement, the other observations about the stream channel are not overlooked.

In the in-class part of the lab, students often struggle with graphing of the stream channel and calculating the stream channel's area and discharge. Help them make sure their results are reasonable and direct them to check with each other and re-do the calculations as needed.

Assessment

Assessment should be based on the following criteria:

- Student's complete and thorough answering of all questions in the lab.

- Student's compliance with instructions and procedures outlined in the lab.

- Accuracy of field measurements (within reasonable range of error).

- Accuracy of cross-section graph (within reasonable range of error) and consistency with field data collected.

- Student's ability to provide sound and reasonable interpretations of stream dynamics based on the observations made in the field.

- Student's understanding of the variables involved in stream systems, specifically as it concerns to stream discharge variations and natural and human factors affecting stream discharge, erosion and flooding at the watershed.

- Student's ability to recognize human impact on the watershed and to envision water management options for urban stream restoration and conservation.

References and Resources

The instructions on stream discharge measurements were developed in part by expanding on stream discharge methods included in the following USGS article:

http://ga.water.usgs.gov/edu/measureflow.html

and in the following online stream discharge lab:

John Stamm, http://www.risner.org/david/

Swann Do, Gary Novak, "Virtual River" http://www.sciencecourseware.org/VirtualRiver/

"Geology Labs Online Project" (sponsored by grants from http://www.nsf.gov/ and http://www.calstate.edu/)

These would be great resources to provide to students in advance to familiarize them with stream discharge measurement methods.

In addition, this lab is part of a broader service-learning field project that I have developed in collaboration with Charles K. Dodd, Geography professor at Shoreline Community College and Brian Landau, Water and Environmental Services manager at the City of Shoreline. This project has been conducted in geology and geography courses for the last several years. Project's goals and progress updates have been presented at several "Curriculum for the Bioregion meetings" and at the "Geological Society of America" meetings in 2009 and 2010. Exact references below:

"Monitoring the Fluvial System of Boeing Creek (Shoreline, WA): A Service Learning Opportunity in the Geosciences." 2010 Annual Meeting of the Geological Society of America, Denver, CO (October 31, 2010).

"Monitoring the Fluvial System of Boeing Creek (Shoreline, WA): A Service Learning Opportunity."

2009 Annual Meeting of the Geological Society of America, Portland, OR (October 19, 2009).

Also the following website is referenced in the activity as an example of a sustainable drainage project by the City of Seattle: http://www2.cityofseattle.net/util/tours/seastreet/slide1.htm

Evergreen State College