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

A Boom Town Story

Vacancies Fall and so does worker productivity

Lower productivity means we need to hire still more workers!

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”

Another Story from the Electric Power Industry in the 1970s-1980s

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.

The Death Spiral

The Death Spiral in Context

Linking Existing Models Together Doesn’t Work

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

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

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

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

The Salmon of the Tucannon River

The Tucannon River

Eggs & Emergent Fry

The Salmon Life Cycle

Juveniles: Spend One Year Competing for Space in the Habitat

The Smolt Migration

p. 155: Around 22,000 Returning Adults

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!

The Salmon Model

Months in Each Stage of the Life Cycle month life cycle

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

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

Key Loops

Do We Get S-Shaped Growth Under Undisturbed Conditions?

Do We See Large Variations?

Do We See A Decline in Returns From Development?

50% Harvesting Starting in 120 th Month

Remainder of 50% Harvesting Simulation

Focus on Harvesting

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

Example of a Student Project Migration InputsHabitat Inputs Project Idea: Simulate Carrying Capacity in the Model

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

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

Information Buttons in Student Model

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

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

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

Nearly Finished on $7 million project

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

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

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

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

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