Humans as Geomorphic Agents
Summary
An introduction to order-of-magnitude calculations and reading quantitative journal articles.
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Context
Audience
Introductory quantitative course in environmental science
Skills and concepts that students must have mastered
Comfort with algebra
How the activity is situated in the course
This is the first problem set of the semester
Goals
Content/concepts goals for this activity
understanding order-of-magnitude calculations and dimensional analysis
Higher order thinking skills goals for this activity
critical reading skills of peer-reviewed literature, connecting calculus concepts to plot interpretation
Other skills goals for this activity
group discussion of peer-reviewed article
Description of the activity/assignment
1) The students read an article from the literature on humans as geomorphic agents as an introduction to order-of-magnitude calculations.
2) The class discusses the article in a 50-minute class
3) The students complete a problem set that introduces them to dimensional analysis, walks them through a comparison of the article's results to natural geomorphic rates, and explores how the author derived the article's final numbers.
4) Once the students are done with the problem set, the class discusses the results and implications as a group.
2) The class discusses the article in a 50-minute class
3) The students complete a problem set that introduces them to dimensional analysis, walks them through a comparison of the article's results to natural geomorphic rates, and explores how the author derived the article's final numbers.
4) Once the students are done with the problem set, the class discusses the results and implications as a group.
Determining whether students have met the goals
Evaluation is based on the problem set answers and the quality of the discussion.
More information about assessment tools and techniques.Teaching materials and tips
- Activity Description/Assignment (Microsoft Word 66kB Aug1 08)
- Pre-activity preparation includes examples of order-of-magnitude (back-of-the-envelope) calculations. I also explain how to visually (geometrically) measure the area under a curve, and what this number means (calculate total earth-moving from rate of earth-moving). I do not emphasize strategies for reading scientific papers, because this paper is fairly straight-forward.
The paper discussion includes each student's one-word reaction to the paper (interesting, boring, frightening, etc.). We also discuss an example calculation that would have been used in the paper, such as how you could calculate earth-moving for Roman road system. We look at plots to ensure that the students understand that unintentional earth-moving is more significant than intentional earth-moving. Finally, as motivation for the problem set, I make sure they understand that a comparison is needed to assess whether the human earth-moving is "a lot" or "problematic." We return to a discussion of this topic after the students complete the problem set. - Solution Set (Microsoft Word 82kB Jul29 08)
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Other Materials
Supporting references/URLs
The students read:
Hooke, R.L., 2000, On the history of humans as geomorphic agents: Geology, v. 28, p. 843-846.
Some data comes from:
Hallet, B., Hunter, L., and Bogen, J., 1996, Rates of erosion and sediment evacuation by glaciers: A review of field data and their implications: Global and Planetary Change, v. 12, p. 213-235.
Hooke, R.L., 2000, On the history of humans as geomorphic agents: Geology, v. 28, p. 843-846.
Some data comes from:
Hallet, B., Hunter, L., and Bogen, J., 1996, Rates of erosion and sediment evacuation by glaciers: A review of field data and their implications: Global and Planetary Change, v. 12, p. 213-235.