1 / 31

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

eperry
Télécharger la présentation

Modeling Earth Processes using Spreadsheets and Commercial Models

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  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?

More Related