title: Forecasting acidification effects using a Bayesian calibration and uncertainty propagation approach.
abstract: We present a statistical framework for model calibration and uncertainty estimation for complex deterministic models. A Bayesian approach is used to combine data from observations, the deterministic model, and prior parameter distributions to obtain forecast distributions. A case study is presented in which the statistical framework is applied using the hydrogeochemical model (MAGIC) for an assessment of recovery from acidification of soils and surface waters at a long-term study site in Norway under different future acid deposition conditions. The water quality parameters are coupled with a simple dose-response model for trout population health. Uncertainties in model output parameters are estimated and forecast results are presented as probability distributions for future water chemistry and as probability distributions of future healthy trout populations. The forecast results are examined for three different scenarios of future acid deposition corresponding to three different emissions control strategies for Europe. Despite the explicit consideration of uncertainties propagated into the future forecasts, there are clear differences among the scenarios. The case study illustrates how inclusion of uncertainties in model predictions can strengthen the inferences drawn from model results in support of decision making and assessments.
authors.affiliation: Norwegian Institute for Water Research, Gaustadalleen 21, 0349 Oslo, Norway, Norwegian Computing Center, P.O. Box 114 Blindern, 0314 Oslo, Norway. thorjorn.larssen@niva.no
authors.forename: Thorjørn
authors.initials: T
authors.lastname: Larssen
authors.forename: Ragnar B
authors.initials: RB
authors.lastname: Huseby
authors.forename: Bernard J
authors.initials: BJ
authors.lastname: Cosby
authors.forename: Gudmund
authors.initials: G
authors.lastname: Høst
authors.forename: Tore
authors.initials: T
authors.lastname: Høgåsen
authors.forename: Magne
authors.initials: M
authors.lastname: Aldrin
mesh_terms: D000143:Acids / Q000737:chemistry*; D000818:Animals; D001499:Bayes Theorem; D002138:Calibration; D004305:Dose-Response Relationship, Drug; D005544:Forecasting; D016013:Likelihood Functions; D014337:Trout; D035501:Uncertainty
chemical_list: D000143:Acids