1. General Model Information

Name: Interactive Model for Ranking the Potential of Organic Chemicals to Contaminte Groundwater

Acronym: CHEMRANK


Main medium: terrestrial+aquatic
Main subject: ecotoxicology, biogeochemistry, hydrology
Organization level: ecosystem
Type of model: not specified
Main application:
Keywords: organic chemicals, leaching, mobility, advection, degradation, soil layers, vadose zone, water-air-soil phases, groundwater

Contact:

Distributor:
University of Florida
Institute of Food and Agricultural Sciences, Software
Support: Zazveta,F.
Phone: 904 - 392-3196
FAX: 352 - 392-3920

Author(s):

David L. Nofziger, P.S.C. Rao and A.G. Hornsby

David L. Nofziger
Oklahoma State University;
Plant and Soil Sciences Department;
368 N. Agricultural Hall;
Stillwater, OK 74078-6028
phone: 405-744-6420
fax: 405-744-5269
email:dln@soilwater.agr.okstate.edu
homepage: http://clay.agr.okstate.edu/plantsoilsci/faculty/dln/nofziger.html

P.S.C. Rao
Soil & Water Science Department,
P.O. Box 110290
University of Florida,
Gainesville, FL 32611-0290
phone: 352-392-1951 (secretary) or 352-392-3021 (voice mail)
fax: 352-392-3902
email: pscr@GNV.IFAS.UFL.EDU
homepage: http://gnv.ifas.ufl.edu/~SOILWEB/rao.HTM

A.G. Hornsby
Soil and Water Science Department
2169 McCarty Hall
Gainesville, FL 32611
email:agh@gnv.ifas.ufl.edu
homepage: http://muck.soils.ufl.edu/people/agh/hornsby.html

Abstract:

Purposes:
CHEMRANK is interactive software procedure designed to provide multiple schemes for ranking the potential for organic chemicals to leach into ground water for different soils and conditions. Four ranking schemes are supported by software, each having different data requirements, ranking criteria, and assumptions.

Processes Simulated:
Partitioning to water-air-soil phases, advection and degradation.

CHEMRANK utilizes four schemes:
The schemes are based on rates of chemical movement or relative rates of mobility and degradation of the chemicals within the vadose (unsaturated) zone. Two schemes are based on the rates at which chemicals might leach through the unsaturated (vadose) zone (steady state groundwater recharge rates); the other two schemes require daily rainfall and evaporation data and use the relative rates of mobility and degradation of the chemicals within the vadose zone.

Output Parameters:
Includes calculated Retardation Factor, Attenuation Factor, Travel Time, and Mass Emissions for each chemical, and relative rank of chemical for each scheme.

Internal Diagnostics: Moderate

Critical Assessment:
Strengths of Model:
Simplicity and ease in use; fundamental processes accounted for; ability to use and maintain data bases.

Weaknesses of Model:
Recharge (effective rainfall or irrigation) must be calculated externally; water-balance and physicochemical processes are simplicit.

Current Version No.: 1988

Costs: MS- DOS. Nominal cost to cover distribution.

sources of abstract: American Crop Protection Association (ACPA) model database (04/1998); EPA/CSMoS database (see links at further information in the www)


II. Technical Information

II.1 Executables:

Operating System(s): Modest - IBM compatible 8088 with 512K bytes RAM; MS-DOS 2.0 or higher. Pre- and Post-Processors: Includes full-screen editor for development and maintenance of required input files. Input files serve as soil and chemical data bases which can be built on for future evaluations. Graphic Capability: Simple "line-printer" graphics are currently available.

II.2 Source-code:

Programming Language(s):
Not routinely distributed with executable.
Version Control: Distributed by Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611

II.3 Manuals:

Well-structured documentation includes model theory, file structure and format, and example applications. (see References)

II.4 Data:



III. Mathematical Information


III.1 Mathematics


III.2 Quantities


III.2.1 Input

Input Parameters:(Vary depending on scheme)

III.2.2 Output

Output Parameters:
Includes calculated Retardation Factor, Attenuation Factor, Travel Time, and Mass Emissions for each chemical, and relative rank of chemical for each scheme.

Output Flexibility:
User control over several output tables and graphs and whether output is directed to screen, printer, or output file.


IV. References

Hornsby, A.G. 1987. Software for teaching principles of chemical movement in soil. pp 193 - 200. In: F.M. D'Itri and L.G. Wolfson (eds.) Rural Groundwater Contamination. Lewis Publishers, Inc. Chelsea, MI. 416 pages.
Nofziger, D.L. and A.G. Hornsby. 1987. Interactive simulation of chemical movement in soil. pp 319-328. In: D.M. Fairchild (ed.), Ground Water Quality and Agricultural Practices. Lewis Publishers Inc. Chelsea, MI.
D.L. Nofziger, P.S.C. Rao, and A.G. Hornsby, 1988. CHEMRANK: Interactive Software for Ranking the Potential of Organic Chemicals to Contaminate Groundwater, Circular 788, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida
Pennell, K.D., A.G. Hornsby, R.E. Jessup, and P.S.C. Rao. 1990. Evaluation of five simulation models for predicting aldicarb and bromide behavior under field conditions. Water Resources Res. 26:2679-2693.
Hornsby, A.G., P.S.C. Rao, J.G. Booth, P.V. Rao, K.D. Pennell, R.E. Jessup, and G.D. Means. 1990. Evaluation of Models for Predicting Fate of Pesticides. Project completion report, FDER Contract No. WM-255. Soil Science Department. University of Florida. 130 pages.
Nofziger, D.L., J.-S. Chen and A.G. Hornsby. 1996. Impact of uncertain soil parameter values upon predicted risk of pesticide leaching to ground water. In: Nettleton, W.D., A.G. Hornsby, R.B. Brown, and T.L. Coleman (eds.) Data Reliability and Risk Assessment in Soil Interpretations. SSSA Special Publication No. 47. Soil Science Society of America, Inc. Madison, WI., USA. 1996.



V. Further information in the World-Wide-Web



VI. Additional remarks

Support Group:
Department of Agronomy
Oklahoma State University
Tele: (405) 744-6418

Soil Science Department
University of Florida
Phone: (904) 392-1951

Validations Reported:
Algorithms have been validated against other more sophisticated models.


Last review of this document by: Juergen Bierwirth Mon Oct 12 15:14:10 MET 1998
Status of the document:
last modified by Tobias Gabele Wed Aug 21 21:44:40 CEST 2002

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