Modeling & Forecasting

The ability to forecast, evaluate and compare future conditions of an ecosystem in response to the physical modifications (alternative plans including a no-action alternative) is fundamental to the planning process.

Key Components of Forecasting

• Identify specific physical and biological properties to be forecasted (relative to the metrics).
• Determine the range of assumptions used to project the future without-project and with-project conditions and project alternatives.
• Establish the spatial scale and temporal period of the analysis.
• Identify the uncertainties that will influence the accuracy and precision of the forecast.
• Identify of an existing forecasting model to use or develop a new model tailored to the project.

The ultimate utility in any forecasting method lies in its ability to determine:

1. What is the best alternative from the range being evaluated?
2. Is the selected alternative a worthwhile investment of federal resources?

Available tools for forecasting benefits range from best professional judgment and simple index models to complex dynamic models that generate outputs for multiple ecosystem attributes. Forecasting the likely effects of a project and calculating ecosystem benefits often require the use of multiple, interlinked models. In most cases, a hydrologic model will be used to forecast the physical outputs of a project, and output from this model will serve as input to one or more additional models used to forecast ecological metrics or indicators.

Regardless of the models used to forecast ecosystem metrics, the EBA will usually require a separate model to synthesize forecast metrics into an overall calculation of benefits. EBA models are generally simple compared with the models used to predict the physical and ecological effects of the project. The accuracy and corresponding levels of uncertainty of a benefits forecast depend not only on the EBA model but on the choice and application of the underlying models used to forecast project effects and ecosystem metrics.

Related Resources


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Foundation Reading

• Swannack, T. M., Fischenich, J. C., Tazik, D. J. (2012). ERDC/EL TR-12-18: Ecological Modeling Guide for Ecosystem Restoration and Management

Other Suggested Reading

• Killgore, K. J., Hoover, J. J., Murphy, C. E. (2008). EMRRP-ER-10: Library of Habitat Models to Evaluate Benefits of Aquatic Restoration Projects on Fishes
• McKay, S. K., Pruitt, B. A. (2012). EMRRP-EBA-14: A Framework for Developing Regional Environmental Benefits Models
• McKay, S.K (2009). EMRRP-EBA-03: Reducing Spreadsheet Errors

Other Products

• EBA Glossary

Tools

• Ecosystem Restoration Model Library
• Nearest Neighbor - An ArcGIS v.9 Tool for the Analysis of Landscape Patches
• Patch Calculator - An ArcGIS v.9 Tool for the Analysis of Landscape Patches
• Patch Connectivity - An ArcGIS v.9 Tool for the Analysis of Landscape Patches
• Patch Disturbance - An ArcGIS v.9 Tool for the Analysis of Landscape Patches
• SAND Model

Webinars

• Avoiding Spreadsheet Errors & Techniques for Normalizinjg Ecosystem Benefits
• Delta Streams Restoration
• ECO-PCX Model Library
• HGM Applications in Ecosystem Restoration
• Model Certification
• The Use of Professional Judgement
• Truckee River Fish Passage