Modeling the Environment: A Call for Interdisciplinary Modeling

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Modeling the EnvironmentA Call for
Interdisciplinary Modeling
1st Edition 1999 2nd Edition 2009 (the
benefits of interdisciplinary modeling using
system dynamics)
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A Boom Town Story
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Vacancies Falland so does worker productivity
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Lower productivity means we need to hire still
more workers!
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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

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Another Storyfrom the Electric Power Industry
in the 1970s-1980s
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The Vicious Circle Makes the Headlines
The Vicious Circle that Utilities Cant Seem to
Break new plants are forcing rate
increases- further cutting the growth in
demand The Electricity Curve Ball declining
demand and increasing rates.
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The Death Spiral
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The Death Spiral in Context
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Linking Existing Models TogetherDoesnt Work
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OK, lets 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

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Conclusions from the Spiral Study

• Waiting for regulators to raise rates wont
  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

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The 1980s The Move to Small Scale

• Cancellation of nuclear plants
• Shift to smaller coal plants
• Invest in PURPA cogeneration
• Utility conservation programs

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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

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The Salmon of the Tucannon River
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The Tucannon River
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Eggs Emergent Fry
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The Salmon Life Cycle
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Juveniles Spend One Year Competing for Space in
the Habitat
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The SmoltMigration
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p. 155 Around 22,000 Returning Adults
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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!
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The Salmon Model
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Months in Each Stage of the Life Cycle
48 monthlife cycle
1
6
12
4
1
12
12
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Parameters
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3,900
50
25
90
Density Dependent
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Juvenile Loss Depends on Density
Carrying Capacity 400,000
The Beverton-Holt Curve page 154
Fraction Survive At low Density 0.5
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KeyLoops
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Do We Get S-Shaped Growth Under Undisturbed
Conditions?
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Do We See Large Variations?
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Do We See A Decline in Returns From Development?
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50 Harvesting Starting in 120th Month
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Remainder of 50 Harvesting Simulation
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Focus on Harvesting
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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

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Example of a Student Project
Migration Inputs
Habitat Inputs
Project Idea Simulate Carrying Capacity in the
Model
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Students Stocks Flows
start with 25 miles of Degraded River with
a capacity of 1 thousand smolts/mile
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Fully Restored River
the other 25 miles of habitat is Mature
Restored River with 8.3 thousand smolts/mile
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Information Buttons in Student Model
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Restoration Spending
For example 25 miles _at_ 52 per foot It takes
around 7 million to restore the river.
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Nature Completes the Job
The student assumed that nature will convert
recent restored miles to mature habitat at the
rate of 10 per year.
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River restored adult counts are up not
surprising!
The surprise comes when you experiment with the
harvest fraction.
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Nearly Finished on 7 million project
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The adult returns are climbing we are trying
85 harvesting
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Continuing with 85 harvesting the Governor is
happy with the 5 million in value
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Finish the Experiment _at_ 85 harvesting
Harvest is sustainable Value of harvested fish
exceeds 7 million!
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One Student Sees the Value of Interdisciplinary
Modeling
Im 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
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Close with one students wish With better
understanding might come better strategies to
rebuild the salmon runs.