Pacific Salmon Environmental and Life History Models: Advancing Science for Sustainable Salmon in the Future

Uncertainty in a Complex Salmon Habitat Model

Paul McElhany, E. Ashley Steel, David Jensen, and Karen K. Avery

doi: https://doi.org/10.47886/9781934874097.ch17

Abstract.—The Ecosystem Diagnosis and Treatment (EDT) model has been widely applied in developing recovery goals and in identifying recovery actions for Pacific salmonids. We conducted a sensitivity analysis of this complex model to estimate prediction intervals and to determine which parameter uncertainties have the greatest influence on model output precision. We used the global sensitivity method of Sobol, but applied a hierarchical structuring of model parameters because the model incorporates a very large number of parameters. Initial results suggest that the model prediction intervals are large enough to affect management decisions and that the model may be most sensitive to parameters that cannot be controlled by user input. Sensitivity analysis of large, complex models like EDT is both possible and necessary for making robust natural resource management decisions.