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Modeling Earth Processes using Spreadsheets and Commercial Models

Modeling Earth Processes using Spreadsheets and Commercial Models. William Locke/David Mogk Dept. of Earth Sciences Montana State University, Bozeman MT. Why Modeling?. Effective learning is experiential! Substitute arithmetic/mathematics for: Space Loess deposition Time

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Modeling Earth Processes using Spreadsheets and Commercial Models

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  1. Modeling Earth Processes using Spreadsheets and Commercial Models William Locke/David Mogk Dept. of Earth Sciences Montana State University, Bozeman MT

  2. Why Modeling? • Effective learning is experiential! • Substitute arithmetic/mathematics for: • Space • Loess deposition • Time • Thrust-belt evolution • Safety • Thermohaline circulation • Money!

  3. What do modelers do? • “A major purpose of scientific investigation is to describe reality through models” Gauch, 1993, Am. Sci., 81, 468. • “..what some researchers are calling the ‘third branch of science’ - using…computers to simulate physical processes..” Pool, 1993, Science, 260, 1077. • “..predict the future state of a system with tolerable certainty” Denning, 1990, Am. Sci., 78, 496.

  4. Caveats(Denning, 1990, American Scientist, 78, 498) • “We must come to understand the domains over which a given model is reliable..” • “Systems whose rules can…change in unpredictable ways are unlikely to have a reliable…model.” • “…it is easy to substitute the model for reality and to confuse our opinions with ‘scientific facts’ supported by the model.”

  5. Why Spreadsheets? • Ubiquitous • AppleWorks, Microsoft Works, Quattro, Lotus… • Visually Powerful Graphics • 2-D (XY, Line), 3-D (Ribbon, Surface)… • “Translucent” - not “Black Box” • point-and-click cell contents • “What-if?” • real-time graphical response to changing inputs

  6. Modeling in ESCI 307 - “Principles of Geomorphology” • Assumption: • One application is “Exposure” • Two applications are “Familiarization” • Three applications are “Competence” • Four applications are “Mastery” • How far do you want to get this year? • Mastery of spreadsheet skills - exposure to and familiarization with specific applications

  7. LaboratoryMechanics • Traphagen 100 • 10 computers (in pairs, out-facing) + instrux. • Teams of 2 or 4 • Face in for “lecture”, map work, specimens • One instructor and a teaching assistant are generally required.

  8. SCARP1 - Scarp Evolution • Exposure to spreadsheet practice • Block operations • Graphing • Theory of slope modeling • Mass redistribution • Running mean

  9. Outcomes - SCARP1 • “Way-cool graphics!” • “I already knew that.” • “Oops! I lost it!” • “It’s not real” but “Material eroded from the top accumulates at the bottom”. • “It looks like chemical diffusion.” • “Measure all of the possible variables and the slope responses.”

  10. Discussion - Scarp1 • Do you use spreadsheets, personally? • If so, why - what do you find useful? • Is a lab teaching spreadsheeting worthwhile? • Is the graphical capability valuable for other applications than modeling?

  11. SCARP2 - Scarp Evolution • Familiarization with • Block ops. & Graphing • Exposure to • Absolute cell refs. • Practice of slope modeling • Acceleration of gravity • Disequilibrium - “Erosivity”

  12. Outcomes - SCARP2 • “It looks just like SCARP!” • “You didn’t really include all of the variables.” • “How do I: • add a resistant layer?” • mimic a deluge?” • model a stream at the toe?” • …?”

  13. Discussion - SCARP2 • Is this a good way to learn about the effects of g•sin? • Is this a good way to learn about probabilistic natural processes? • Is it worth doing additional exercises?

  14. LONGPRO - Stream Evolution • Competence in block operations & graphing • Familiarization with absolute cell references • Exposure to equations • Interrelationships between modeling and collection of field data.

  15. Outcomes - LONGPRO • About 70% of teams “succeed” - matching real and modeled profiles (but with unreal parameters - e.g., a tiny output of m-scale particles). • About 40% of teams succeed. • Success requires changing one variable away from the optimal solution, then another one towards it.

  16. Discussion - LONGPRO • Is the integration of field data with modeling worth the investment of two laboratory periods? • Is the failure rate (30% total, 60% partial) acceptable given the complexity of natural systems? • Do those who don’t succeed, fail?

  17. GLACPRO - Glacier Reconstruction • Mastery of block operations and graphing • Introduction to research • Team activity • Resource allocation • Interaction with other groups • Quality control

  18. Outcomes - GLACPRO • A surprising number of results are incorrect. • No intuitive knowledge of what a glacier “should look like”. • Great difficulty meeting as teams outside of class. • Inevitable team friction. • Publishable products (when “massaged”).

  19. Discussion - GLACPRO • Is the difference between “glacial extent” and “modeled glacial extent” clear? • Are team/interactive exercises worth the degradation of content? • Are exercises with no “right answer” fair to students (as for grading purposes)?

  20. Data Downloading • Sources • USGS • Other? • Formats • Parsing • Web Tables X • Outcomes • Trends • Statistics

  21. Log10 transformation

  22. Magnitude/Frequency

  23. Stream Rating Curves

  24. Flood Recurrence Intervals

  25. Discussion - Download • What numerical data sets exist? • Does spreadsheet manipulation result in increased learning effectiveness? • Would a field trip to a stream gauge be a more effective teaching tool?

  26. Virtual MODFLOW • The standard in professional groundwater modeling - $750 (incl. academic discount!) • The Scientific Software Group: http://www.scisoftware.com/ • Downloadable demo: http://www.scisoftware.com/products/visual_modflow_demo/visual_modflow_demo.html

  27. ModflowGrid

  28. Discussion of Visual MODFLOW • Is it appropriate to use a commercial product for a class activity? • Is “black-box modeling a valuable learning tool?

  29. General Modeling Issues • At what academic level is modeling critical? • Relative importance of physical, theoretical and mathematical models? • Optimal execution - homework, solo lab, team lab, class demo…? • Optimal tradeoff against content, field trips, map exercises, quizzes…?

  30. General Issues relating to DLESE • Who should maintain such models? • Author? DLESE? Other agency? • How can DLESE promote this activity? • Action Items? • User Group? • “White Paper” on modeling pedagogy? • Testing Service for models?

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