Error and Uncertainty Analysis for Ecological Modeling and Simulation
RC-1096
Objective
Example of Modeling System with Error
Most data employed in simulation modeling are estimates of the true parameters and, therefore, have an associated uncertainty. Error budgets can be used to assess the quality of the overall simulation system. Although progress has been made in the areas of uncertainty analysis and error budgets, there is a need to develop more advanced statistical and computational tools. These tools will enable model users to jointly assess and quantify the sources and magnitude of errors associated with large-scale Department of Defense (DoD) simulation models used for resource assessment and management.
With the growing importance of simulation modeling in natural and cultural resource assessment and management, the DoD recognizes the need for a comprehensive framework to analyze uncertainty in simulation results. Over four years, this project will develop the methodological framework to conduct this uncertainty assessment.
Technical Approach
Research has begun by developing a Geographic Information System-based methodology to make spatial and temporal predictions, analyze uncertainty, and build error budgets for soil erosion status based on and applied to military training. Through this methodology, a grid-based database is generated containing a digitized elevation model and soil, rainfall, and vegetation maps (models). Spatial and temporal predictions of soil loss are made at different optimal operational scales. Using sensitivity techniques, spatial sensitivity of the input parameters on the prediction are analyzed. The error budget for the whole population, or a homogeneous sub-area, is determined by applying both analytical and Monte Carlo approaches. In addition, spatial error distributions and patterns are identified and quantified using geostatistical techniques, literature surveys, interviews, statistical methods, previous studies, and field studies, if necessary. Once these errors are estimated, component models will be developed to represent these errors and design specifications for the portable software package that will be created.
Results
A detailed analysis of a case study in Fort Hood, Texas, was begun. Significant progress was made in both identifying the errors associated with the inputs and designing approaches to obtain that error information when it was unavailable. Researchers began the process of identifying errors in simulation systems. Currently, 100 different sources of error have been identified. Scientists also began to develop a formal framework for error analysis of large spatiallyexplicit simulation models, which also is being applied to the Fort Hood case.
Project Documents
Symposium & Workshop
FY 2013 New Start Project Selections
Points of Contact
Principal Investigator
Dr. George Gertner
University of Illinois
Phone: 217-333-9340
Fax: 217-244-3219
Program Manager
Resource Conservation and Climate Change
SERDP and ESTCP
Project Documents
Document Types
- Fact Sheet - Brief project summary with links to related documents and points of contact.
- Final Report - Comprehensive report for every completed SERDP and ESTCP project that contains all technical results.
- Cost & Performance Report - Overview of ESTCP demonstration activities, results, and conclusions, standardized to facilitate implementation decisions.
- Technical Report - Additional interim reports, laboratory reports, demonstration reports, and technology survey reports.
- Guidance - Instructional information on technical topics such as protocols and user’s guides.
- Workshop Report - Summary of workshop discussion and findings.
- Multimedia - On demand videos, animations, and webcasts highlighting featured initiatives or technologies.
- Model/Software - Computer programs and applications available for download.
- Database - Digitally organized collection of data available to search and access.