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What's New in AQUATOX Release 3.1 Plus?
AQUATOX Fact Sheet (EPA-820-F-12-023) August 2012
AQUATOX Release 3.1 Plus includes the following enhancements:
- Option to model nutrient limitation in plants based on internal rather than external nutrients. This allows for luxury uptake of nutrients during high-nutrient periods and expenditure of nutrient stores during lower-nutrient periods. Concentrations and derivative rates may be output from these new internal-nutrient state variables as well as the nutrient-to-organism ratio for each plant. This option should improve the prediction of the timing and duration of algal blooms.
- Sinking of plants and suspended detritus is now affected by the salinity & therefore the density of water in non-estuary segments.
- New outputs for net primary productivity, pelagic invertebrate biomass, benthic invertebrate biomass, and fish biomass.
- Capability to load and save observed data to a file to move from one study to another.
- Significantly optimized loading and saving of very large aps or als files.
- For moving water (streams and rivers), the average water temperature must drop below 0 deg. C before ice cover is assumed.
AQUATOX Release 3.1 includes numerous significant enhancements over previous versions that increase the realism and utility of the model. The most important enhancements include:
- Addition of sediment-diagenesis "steady-state" mode to significantly increase model speed;
- Modification of denitrification code in order to simplify calibration and to achieve alignment with other models;
- Enabled importation of equilibrium CO2 concentrations to enable linkage to CO2SYS and similar models;
- New BOD to organic matter conversion relying on percent-refractory detritus input; input and output BOD is clarified to be "carbonaceous" BOD.
- Refinements for floating plants:
- Added floating option for plants other than cyanobacteria (formerly labeled "blue-green algae”)
- Converted the averaging depth for floating plants to the top three meters to more closely correspond to monitoring data
- Floating plants now explicitly move from the hypolimnion to the epilimnion when a system is stratified.
- Modifications to PFA (perfluoroalkylated surfactants) model to increase flexibility:
- Uptake rates (K1s) and elimination rates (K2s) are visible and editable for animals and plants
- New interface to estimate animal K1s and K2s as a function of chain length
- Improved gill-uptake equation for invertebrates.
- Bioaccumulation and toxicity modeling improvements:
- Optional alternative elimination-rate estimation for animals based on Barber (2003) ; works best with PCBs;
- Updated ICE (toxicity regressions), based on new EPA models released in February 2010 and improved AQUATOX ICE interface;
- Addition of output of K1, K2, and BCF estimates.
- Improved sensitivity and uncertainty analyses:
- "Output to CSV" option for uncertainty runs so that complete results for every iteration may be saved and examined;
- Option for non-random sampling for "statistical sensitivity analyses";
- A "reverse tornado" diagram (effects diagram) that shows the effects of each parameter change on the overall simulation;
- Nominal range sensitivity analysis has been added for linked- segment applications.
- Database Improvements:
- AQUATOX database search functions dramatically improved;
- "Scientific Name" field added to Animal and Plant databases.
- Interface and Data Input Improvements:
- Software and software installer is 64-bit OS compatible;
- Added an option in the "Setup" screen to trigger nitrogen fixation based on the N to P ratio;
- Addition of output variables to clarify whether photosynthesis is sub-optimal due to high-light or low-light conditions;
- Time-varying evaporation option in the "Site" screen has linkage from the "Water Volume" screen;
- Grid mode within a study so that all animal, plant, and chemical parameters in a study can be tabulated, examined, edited, and exported to Excel;
- Added capability to input time-series loads of fish based on fish stocking;
- Updated HSPF WDM file linkage to be more generally applicable (does not require use of WinHSPF, the version of HSPF contained in BASINS);
- Enabled hourly loadings for the following variables: all nutrients, CO2, Oxygen, Inorganic suspended sediments (sand/silt/clay), TSS, Light, Organic Matter;
- "Graph Setup" window now enabled for linked-mode graphics;
- Other minor interface improvements.