Field observations of mass transport

Jodi L Ryder, Central Michigan University

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Summary

In this activity students use published data from the Massachusetts Military Reservation to observe and predict mass transport parameters.

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Context

Audience

This activity is from a 300 level hydrogeology course which is optional for geology majors and required for environmental science and geology with a hydro/environmental concentration majors

Skills and concepts that students must have mastered

Students need to have mastered 1-D flow models so that they can incorporate them into understanding the transport of contaminants within a flow field.

How the activity is situated in the course

This activity is completed over the last two three hour lab sessions of the term. Part 1 is completed with paper and pen in small groups. Part 2 is completed in a computer lab using a spreadsheet that is provided with a working 1-D advection dispersion model.

Goals

Content/concepts goals for this activity

The concepts to understand from this activity are advection and dispersion. The goals are to relate the parameters of the 1D Advection-dispersion model to the physical properties of real plumes, practice making hand calculations and compare them to a computerized model, and explore the relationships between the parameters (travel length, travel time, diffusion, dispersion, velocity) and the resulting concentration.

Higher order thinking skills goals for this activity

The higher order thinking skills involved in completing the activity are application of terms used in class to real world data, analysis of complex data in the framework of a simplified mathematical model, and synthesis of results of multiple scenarios to generalize the capabilities and limitations of the simplified numerical model.

Other skills goals for this activity

Other skills include graphing of data and use of Excel software to automate complex repetitive calculations.

Description and Teaching Materials

There are two files. One contains the activity handout with instructions and places for students to write answers and the second is the Excel file containing the model that students experiment with.

Student handout for 1-D AD transport labs (Microsoft Word 297kB Apr29 13)
Excel sheet to accompany 1-D transport lab (Excel 2007 (.xlsx) 15kB Apr29 13)


Teaching Notes and Tips

For the best results, introduce the concepts of advectiona nd dispersion before this activity. Have the students down load LeBlanc et al. 1991 from WRR and skim the paper ahead so they are familiar with this landmark experiment. I let them step through part 1 by themselves while circulating to answer questions. For part 2 we go through the steps 1 by 1 as a group and draw the graphs on the board for discussion.

Assessment

I have the students fill out the handout as they complete the lab and hand in one copy per small group. I use a rubric with 5-6 points per numbered question to grade it. For the most part, this is a lab where most students get near 100% because we discuss the results as we go along.

References and Resources

LeBlanc et al. 1991 is needed to complete the assignmenthttps://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/91WR00241