One-Week Introduction to Stochastic Groundwater Modeling

One-Week Introduction to Stochastic Groundwater Modeling David C. Mays University of Colorado Denver

Annual Meeting Geological Society of America Denver, Colorado, October 27-30, 2013

Outline • Motivation • Spatial Correlation • PMWIN – classroom model – homework exercise

• Monte Carlo • Summary

stochastic hydrogeologist

groundwater consultant

Oppenheimer http://rhapsodyinbooks.files.wordpress.com/2009/01/oppenheimer.jpg?w=230 10/22/20013 Truman http://h-bombbook.com/images/truman.jpg 10/22/2013

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Why Stochastic Modeling? • Translate research to practice • Demonstrate evaluation – top level of Bloom’s Taxonomy

• Show humility – All models are wrong, but some are useful (Box 1979)

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Spatial Correlation

inexpensive http://bethpartin.com/wp-content/uploads/2010/03/Globeville-houses-Feb-2010-600x400.jpg 10/22/2013 expensive http://www.armstrongre.com/upload/Hilltop%201.jpg 10/22/2013 neighborhoods http://collaborativelibrarianship.files.wordpress.com/2010/09/denver-neighborhoods.jpg 10/22/2013

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Classroom Model

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Classroom Model no flow boundary

constant head boundary

extraction well

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Spatially Correlated ln(K)

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Classroom Model

homogeneous

heterogeneous

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Homework Exercise

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Spatially Correlated ln(K)

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Homework Exercise

Report head in cell (25, 14) 12 of 15

Count

Monte Carlo Simulation 6 5 4 3 2 1 0

Histogram 2.98

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3.06

Frequency

2.90

3.14

Upper Limit of Histogram Bin

With small N!

10 5 0 2.85

2.95

3.05

3.10

3.15

3.20

More

Bin

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Summary 1. 2. 3. 4. 5.

Stochastic modeling—worthwhile! Real estate analogy for spatial correlation PMWIN for teaching Modflow Monte Carlo through “crowdsourcing” Give it a shot—fast, fun, and free

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Thank You! FOR MORE DETAILS • learning objectives • step-by-step instructions • Likert assessment results Mays (2010) Journal of Geoscience Education http://dx.doi.org/10.5408/1.3534852

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