Record Display for the EPA National Library Catalog
RECORD NUMBER: 38 OF 729
|OLS Field Name||OLS Field Data|
|Main Title||AQUATOX for windows : a modular fate and effects model for aquatic ecosystems. vol. 3, Model validation reports : addendum.|
|Author||Park, R. A.|
|CORP Author||Environmental Protection Agency, Washington, DC. Office of Water.|
|Publisher||U.S. Environmental Protection Agency, Office of Water,|
|Report Number||EPA 823-R-01-008|
|Subjects||Aquatic organisms--Effect of water pollution on--United States. ; Water--Pollution--United States--Analysis. ; Aquatic ecology--United States--Analysis. ; Aquatic ecology--United States--Computer simulation.|
|Additional Subjects||Ecosystem models ; Aquatic ecosystems ; Toxic chemicals ; Model components ; Applications ; Data considerations ; Calibration ; Biomass ; Documentation ; Quality assurance ; Validation ; Uncertainty analysis ; Environmental factors ; Ecological risk models ; AQUATOX ; Microsoft windows|
|Collation||vi, 35 p. : ill. ; 28 cm.|
The AQUATOX periphyton submodel was successfully calibrated and validated with data from Walker Branch, Tennessee. A single parameter set for diatoms, green algae, and gastropods was developed to fit all twenty treatments in a factorial experiment involving low and high nutrient levels, low and high light levels, and grazing and no grazing in stream-side channels and stream enclosures. A two-year data set for periphyton on cobbles in the stream-bed was used to validate the model for continuous ambient conditions in this woodland stream. Nitrogen, phosphorous, light, and grazing were all limiting, both singly and in combination. Inclusion of a sloughing term based on senescence due to deteriorating environmental conditions and the drag force of currents on exposed periphyton biomass provided a realistic response to limiting environmental factors and was especially useful in modeling the effects of variable flow rates on diatoms and filamentous algae. The model was shown to be calibrated and validated based on the weight of evidence of reproduction of observed patterns of biomass change, concordance of maxima between predicted and observed biomass, and equivalence in predicted and observed means and variances as confirmed by relative bias and F tests.
"EPA-823-R-01-008"--Cover. "November 2001." "This validation study was funded under contract numbers 68-C-98-010 and 68-C-01-0037 to AQUA TERRA Consultants, Anthony Donigian, Work Assignment Manager."--P. iii. Includes bibliographical references (p. 31-32).