![[logo] US EPA](http://www.epa.gov/epafiles/images/logo_epaseal.gif){kind=logo}
Features and Tools
Table of Contents
AQUATOX has been designed to be user-friendly and to provide maximum flexibility. Numerous features have been included to facilitate the modeling process, from model setup and data input, presentation and analysis of results, to easy export of results to spreadsheet programs for additional analysis.
Model setup
AQUATOX is designed to provide maximum control and flexibility in model setup.
- Windows-based (Windows 98, 2000, NT, XP or Vista)
- Note: For optimal performance, Windows XP or Vista is recommended.
- Intuitive study screens
- Control setup allows development of scenarios and management alternatives
- Option to run "control" vs. "perturbed" simulations to isolate effects of a given stressor
- No limits on length of simulation period
- Variable time step
- Modular design gives you control over choice of state variables
- The AQUATOX Wizard helps guide you through the study setup
- Context-sensitive Help files
AQUATOX has a flexible study setup
Data input
AQUATOX is designed to provide a realistic representation of aquatic ecosystems with a minimal amount of detailed site specific information or site calibration.
AQUATOX can accept input data in a wide variety of formats and sources.
Required input data
- Environmental Data:
- Loadings to the waterbody
- General site characteristics
- Biological and Chemical Parameters:
- Biological characteristics of the plants and animals
- Chemical characteristics of any organic toxicant
AQUATOX comes bundled with data libraries that provide default data and parameter sets for different waterbody types, animal and plant species, and chemicals. This is of particular importance for the biological parameters, which are probably the most difficult for a user to obtain. We continue to add to these libraries to expand the range of site types, ecological communities and pollutant types.
AQUATOX can link to BASINS, EPA's GIS and water quality modeling system. This allows you to take pollutant loading predictions from the HSPF or SWAT watershed models and input them directly to AQUATOX.
Environmental loadings can be from multiple sources
- Constant or dynamic
- Point or nonpoint sources
- Upstream contributions
- Atmospheric deposition
- Groundwater and tributaries
Model output and analysis of results
AQUATOX provides output in terms of time varying biomass of the various plants and animal, chemical concentrations in water, and concentrations of the organic toxicant in water, organic sediments and biota. It has numerous features to assist in display and analysis of results:
- Powerful graphing capability
- Default graph library
- X-Y plots, duration and frequency graphs and scatter plots
- Import of observed data to facilitate calibration
- Easy export to EXCEL
Option to save time-varying rates, such as consumption, photosynthesis, and limitation factors on photosynthesis
Uncertainty and automated nominal range sensitivity analysis
Graph and analyze your results easily
Sensitivity and Uncertainty Analysis
There are many sources of variability and uncertainty when modeling ecosystems. AQUATOX 3 now includes a built-in nominal range sensitivity analysis (Frey and Patil 2001), which may be used to examine the sensitivity of multiple model outputs to multiple model parameters; the; the parameters producing the most sensitivity can be compared by means of the automated tornado diagrams. AQUATOX also allows the user to evaluate model uncertainty by varying the value or distribution of input parameters.
Example “tornado diagram” showing the most sensitive parameters for chironomid (midge) larvae biomass.
Assign Distribution to Variables
Sensitivity of Largemouth Bass biomass to pesticide loadings