Model Sensitivity Analysis, Calibration and Uncertainty Evaluation Shortcourse

University of California Davis
Buehler Alumni Center, AGR Room

January 13-14, 2020

organized by

University of California Davis, Chico State University, Larry Walker Associates

&

Groundwater Resources Association of California

Course motivation and description

The Sustainable Groundwater Management Act calls out explicitly for model evaluation and for the evaluation of uncertainty in the models that we develop for the Groundwater Sustainability Plans. Directly from the BMP on modeling, the Department of Water Resources suggests:

“Sustainable groundwater management and policy decisions must be based on knowledge of the past and present behavior of the surface and groundwater system, the likely response to future changes, and the understanding of the uncertainty in those responses.”

The focus of this course is on methods for sensitivity  analysis, data assessment, model calibration, and evaluation of model uncertainty.  The course will introduce these topics and use basic results to provide guidelines for how to use these methods in practice. The course will emphasize  spatially-discretized systems and “snap-on” tools that are not model or code specific (e.g. UCODE_2014 and PEST). Insights and examples of both local and global methods will be presented through hands-on use of local methods in UCODE_2014 and PEST, and global methods  (Morris and Sobol). Basic concepts covered include:

• Analyze data to be used for model development. Based on knowledge of the system, decide how to define parameters.
• Determine parameter values that provide a best fit to observations.
• Calculate predictions and obtain measures of prediction uncertainty.
• Using the initially constructed model, identify parameters important to observations, parameters important to predictions, and observations important to predictions. We will
•  Question whether these simulated relationships are consistent with real-world conditions.
• Assess how much information the data provide and what level of model complexity can be supported by the data
• What potential new data should be collected to improve predictions

Exercises will be provided and used throughout the course and large-scale examples will be highlighted to show how these methods are used in practice. These techniques will be discussed using groundwater model examples but can be applied to other models, and example of applications in different fields will be provided.

Course Instructors

Laura Foglia, Ph.D.
Department of Land, Air, and Water Resources, University of California

Laura Foglia, Ph.D., is an adjunct associate professor at University of California Davis, and a consultant senior engineer with Larry Walker Associates in Davis, California. She holds a Master in Physics from University of Milan, Italy, and a PhD in Environmental Engineering from ETH Zurich, Switzerland. Her research focuses on understanding integrated groundwater/surface water systems at local and macro-scale. Her emphasis is on model calibration and uncertainty analysis applied to different watersheds and different water management problems, from ecohydrological problems to optimization of conjunctive use of surface water/groundwater She has been a research assistant at the Technical University of Darmstadt, Germany, where she taught groundwater and vadose zone modelling courses, and short courses for other universities. At University of California, Davis, she developed a new class on “Inverse Problems” for students in the Civil and Environmental Engineering and Land, Air and Water Resources Departments.

Jonathan Herman, Ph.D.
Department of Civil and Environmental Engineering, University of California 

Jonathan Herman, Ph.D., is an assistant professor in the Department of Civil and Environmental Engineering at the University of California Davis. He received a Ph.D. from Cornell University. His research focuses on water resources planning and management, specifically adaptation of infrastructure and operations under climate change. Additionally, he is the lead developer of the SALib Python package for global sensitivity analysis. Jon is an associate editor for the ASCE Journal of Water Resources Planning and Management and teaches courses on numerical methods and optimization.

Steffen Mehl, Ph.D.
Department of Civil Engineering, California State University Chico

Steffen Mehl, Ph.D.,  is a Professor and Chair of the Department of Civil Engineering at California State University, Chico, where he teaches courses in fluid mechanics, hydrology, and hydraulics. Before joining the faculty at CSU Chico, Dr. Mehl worked as a hydrologist for the National Research Program within the United States Geological Survey (USGS) where his research focused on improving groundwater models as management and predictive tools. He has taught short courses offered by the USGS National Training Center in Denver, CO covering topics on numerical solution of the groundwater-flow equation, groundwater modeling strategies for using local grid refinement, and inverse modeling and sensitivity analysis. He is on the board of associate editors for the journal Ground Water. His research interests include simulation of surface water-groundwater interactions; flow and transport modeling in hydrologic systems; parameter estimation and uncertainty analysis in hydrologic systems; and computational methods for solving hydrologic problems.