Analysis and Discussion Exercises

1. Feedback in the Brine Shrimp Model

Draw a causal loop diagram to show the feedback loops in the model shown in Figure 1.

2. Feedback in the Combined Model

Draw a causal loop diagram to show any feedback loops that work their way through the hydrology sector and the brine shrimp sector of the combined model.

3. Feedback with the Water Export Policy

Draw a causal loop diagram to show any feedback loops that may be attributed to the water export policy from the 5th merger exercise.

4. Is the Whole Model More Than the Sum of its Parts?

Did you arrive at a satisfactory export policy in the 6th and 7th merger exercises? Now imagine that you do NOT have the combined model at your disposal, but you do have access to the two, separate models. Conduct a combination of simulations with the two models operated separately to study the export policy. Do you arrive at a similar conclusion by operating the two models separately?

5. When Are Model Mergers Useful?

Do you feel that the merger of the two Mono Lake models was useful? Did it teach you something new that you could not have learned from operating the two models separately? Under what conditions would you recommend that model mergers be undertaken? For example, would you think if worthwhile to merge the salmon migration model in Chapter 13 with the salmon life cycle model Chapter 14? Or can we learn just as much from these models by operating them separately?