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Model Report

Watershed Health Assessment Tools Investigating Fisheries

Last Revision Date: 09/28/2011 View as PDF
General Information Back to Top
Model Abbreviated Name:

Model Extended Name:

Watershed Health Assessment Tools Investigating Fisheries
Model Overview/Abstract:
WHATIF is software that integrates a number of calculators, tools, and models for assessing the health of watersheds and streams with an emphasis on fish communities. The tool set consists of hydrologic and stream geometry calculators, a fish assemblage predictor, a fish habitat suitability calculator, macro-invertebrate biodiversity calculators, and a process-based model to predict biomass dynamics of stream biota (the BASS model).

The software is built upon a database of stream measurements which serve as inputs to the calculators and tools. The calculators and tools vary in complexity, and can take the form of regression-based predictions up to a process based fish population model, the Bioaccumulation and Aquatic System Simulator (BASS). The toolkit allows the user to investigate a location on a stream or river by examining the data that have been collected at the location, and using the data with the calculators to compare actual conditions with predicted or possible conditions.

For example, the Fish Assemblage Predictor might indicate that a stream in this location would likely support a trout population, while the data show that no trout have been observed. Then, the Habitat Suitability calculator could be used to examine the scores for trout to see if an explanation can be found in the current stream conditions. The user could explore what changes could be made to the stream, such as overhanging vegetation or erosion control, to allow trout to thrive. Finally, trout could be "stocked" in the simulation model to see if they persist and how other species are affected.

All of the data, both original observations and user-generated experimental data, are stored in the central database which allows access by any WHATIF tool or calculator. Thus, the output of one tool can become the input of another tool, and this feature is exploited by some calculators and tools with certain kinds of data.

Keywords: Engineer, scientist, biologist, researcher, watershed manager
Model Technical Contact Information:
Agency Contact:
John M Johnston
Model Homepage: http://www.epa.gov/ceampubl/fchain/whatif/index.html
Substantive Changes from Prior Version: N/A
Plans for further model development: Extension to Gulf of Mexico Estuaries

User Information Back to Top
Technical Requirements
Compatible Operating Systems
Windows XP (sp2)
Other Software Required to Run the Model
Adobe Acrobat
Download Information
Using the Model
Basic Model Inputs
Emap surface & water dataset, WV remap provided
Basic Model Outputs
Water temp, flow, fish community types, species suitability, community dynamics and toxic burdens
User Support
User's Guide Available?
Other User Documents
Check model website:
Availability of User Support
Currently, there are no planned WHATIF training sessions. Technical questions and requests for application source code can be made directly to the author John M Johnston (johnston.johnm@epa.gov)
User Qualifications
Novice to Expert

Model Science Back to Top
Problem Identification
Stream management for fisheries, riparian restoration for habitat improvement
Summary of Model Structure and Methods
Statistical, empirical and process based trophic dynamics
Model Evaluation
See journal articles and reports provided in references on the model's homepage
Key Limitations to Model Scope
Stream segment based approach
Case Studies

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