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Modeling the Environment: A Call for Interdisciplinary Modeling

Modeling the Environment: A Call for Interdisciplinary Modeling. 1 st Edition: 1999 2 nd Edition: 2009 (the benefits of interdisciplinary modeling using system dynamics). A Boom Town Story. Vacancies Fall and so does worker productivity.

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Modeling the Environment: A Call for Interdisciplinary Modeling

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  1. Modeling the Environment:A Call for Interdisciplinary Modeling 1st Edition: 1999 2nd Edition: 2009 (the benefits of interdisciplinary modeling using system dynamics)

  2. A Boom Town Story

  3. Vacancies Falland so does worker productivity

  4. Lower productivity means we need to hire still more workers!

  5. Conclusion of the Boom Town Story • Everybody knew about the vicious circle; but nobody would simulate it • Leaving planners to do so in their head • Insight for some companies: the boom town problem is “our problem” not “their problem”

  6. Another Storyfrom the Electric Power Industry in the 1970s-1980s

  7. The Vicious Circle Makes the Headlines The Vicious Circle that Utilities Can’t Seem to Break: new plants are forcing rate increases- further cutting the growth in demand The Electricity Curve Ball: declining demand and increasing rates.

  8. The Death Spiral

  9. The Death Spiral in Context

  10. Linking Existing Models TogetherDoesn’t Work

  11. OK, let’s build a single model(a Corporate Model) • Workshop by EPRI: 1 of 12 models did the spiral • Workshop for Dept. of Energy: 1 of 13 models did the spiral • Most managers had to simulate the spiral in their head

  12. Conclusions from the “Spiral Study” • Waiting for regulators to raise rates won’t necessarily solve the financial problems • The IOUs could improve their situation by building smaller, shorter-lead time plants • And by slowing the growth in electricity demand through efficiency programs

  13. The 1980s: The Move to Small Scale • Cancellation of nuclear plants • Shift to smaller coal plants • Invest in PURPA cogeneration • Utility conservation programs

  14. Teaching Interdisciplinary Modeling • WSU System Dynamics, Environmental Science • Growing Student Interest • Faculty Interest: NSF Grant for Doctoral Training • Remainder of the Talk: one student learns the value of interdisciplinary modeling

  15. The Salmon of the Tucannon River

  16. The Tucannon River

  17. Eggs & Emergent Fry

  18. The Salmon Life Cycle

  19. Juveniles: Spend One Year Competing for Space in the Habitat

  20. The SmoltMigration

  21. p. 155: Around 22,000 Returning Adults

  22. Is ~20 Thousand Salmon Plausible? The Columbia Basin drainage is around 800 times larger than the Tucannon. 800 times 20 thousand gives around 16 million adults returning to the mouth of the Columbia each year!

  23. The Salmon Model

  24. Months in Each Stage of the Life Cycle 48 monthlife cycle 1 6 12 4 1 12 12

  25. Parameters 50% 3,900 50% 25% 90% Density Dependent 10% 35%

  26. Juvenile Loss Depends on Density Carrying Capacity = 400,000 The Beverton-Holt Curve: page 154 Fraction Survive At low Density = 0.5

  27. KeyLoops

  28. Do We Get S-Shaped Growth Under Undisturbed Conditions?

  29. Do We See Large Variations?

  30. Do We See A Decline in Returns From Development?

  31. 50% Harvesting Starting in 120th Month

  32. Remainder of 50% Harvesting Simulation

  33. Focus on Harvesting

  34. Discussion of Harvesting • Typical results • One team after another finds a sustainable harvest • The salmon population has a natural resilience • Contrast with Fisheries around the world • Fish Banks Game (Meadows) • Norwegian Fjord Experiment (Moxnes) • Fish and Ships (Morecroft) • Over-investment in renewable resources is common • Too many irrigated acres; too little river flows • Too many steers; not enough grazing land • Too many sawmills; not enough harvestable trees

  35. Example of a Student Project Migration Inputs Habitat Inputs Project Idea: Simulate Carrying Capacity in the Model

  36. Student’s Stocks & Flows start with 25 miles of “Degraded River” with a capacity of 1 thousand smolts/mile

  37. Fully Restored River the other 25 miles of habitat is “Mature Restored River” with 8.3 thousand smolts/mile

  38. Information Buttons in Student Model

  39. Restoration Spending For example: 25 miles @ $52 per foot: It takes around $7 million to restore the river.

  40. Nature Completes the Job The student assumed that nature will convert recent restored miles to mature habitat at the rate of 10% per year.

  41. River restored; adult counts are up; not surprising! The surprise comes when you experiment with the harvest fraction.

  42. Nearly Finished on $7 million project

  43. The adult returns are climbing; we are trying 85% harvesting

  44. Continuing with 85% harvesting:the Governor is happy with the $5 million in value

  45. Finish the Experiment @ 85% harvesting Harvest is sustainable; Value of harvested fish exceeds $7 million!

  46. One Student Sees the Value of Interdisciplinary Modeling I’m a fluvial-geomorphologist. I would never have combined river restoration calculations with population biology in this manner. Surprised by the result.Surprised by his ability to get the result

  47. Close with one student’s wish: With better understanding might come better strategies to rebuild the salmon runs.

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