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Record Search Query: ServiceParameters>MODELS>COMPONENT PROCESS MODELS

CFITIM Model: Estimates parameters in several equilibrium and non-equilibrium transport models from solute breakthrough curves
Entry ID: USDA_ARS_CFITIM
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Summary
Abstract: Traditionally, a two-parameter partial differential equation has been used to describe the one-dimensional convective-dispersive equilibrium transport of chemicals in field soils. The parameters in this equation include the dispersion coefficient and a distribution coefficient, the latter accounting for interactions between the chemical and the solid phase of the soil. The resulting model is relatively easy to use for linear equilibrium adsorption. More complex conceptual models have been introduced in attempts to better characterize the simulated system for conditions involving nonequilibrium transport. These models are all based on the assumption that, either for physical or chemical reasons, adsorption does not proceed at an equal rate in all parts of the soil medium. The resulting transport equations contain several parameters which must be quantified before actual predictions can be made in the field. Estimates for these parameters can be obtained by analyzing effluent curves from column displacement experiments. Since several parameters have to be estimated simultaneously, elaborate curve-fitting techniques are often needed. CFITIM is an accurate and easy to use least-squares computer program which may be used for that purpose. Depending upon the exact form of the transport model, the program allows up to five different parameters to be estimated simultaneously.

The report comes with a user manual giving detailed information about the different nonequilibrium models, and how to prepare the data input files for various applications.

[Summary provided by the USDA.]

Related URL
Link: VIEW RELATED INFORMATION
Description: CFITIM Model.
Service Citation
Originators: M. Th. van Genuchten
Title: CFITIM Model: Estimates parameters in several equilibrium and non-equilibrium transport models from solute breakthrough curves
Release_Date: 1981
Provider: USDA Agricultural Research Service
Edition: 1.0
URL: http://www.ars.usda.gov/Services/docs.htm?docid=8912
ISO Topic Category
FARMING
GEOSCIENTIFIC INFORMATION
Access Constraints
The program and manual are available upon request from:

Walter Russell
USDA-ARS U.S. Salinity Laboratory
450 W Big Springs Road
Riverside, CA 92507-4617

Tel: 951-369-4850
Fax: 951-342-4964
wrussell@ussl.ars.usda.gov
Service Provider
Agricultural Research Service, U. S. Department of Agriculture

Service Provider Personnel
Name: WALTER RUSSELL
Phone: 909-369-4850
Fax: 909-342-4964
Email: wrussell at ussl.ars.usda.gov
Contact Address:
U.S. Salinity Laboratory
USDA, ARS
450 West Big Springs Road
City: Riverside
Province or State: CA
Postal Code: 92507-4617
Country: USA
Personnel
WALTER RUSSELL
Role: TECHNICAL CONTACT
Phone: 909-369-4850
Fax: 909-342-4964
Email: wrussell at ussl.ars.usda.gov
Contact Address:
U.S. Salinity Laboratory
USDA, ARS
450 West Big Springs Road
City: Riverside
Province or State: CA
Postal Code: 92507-4617
Country: USA

TYLER B. STEVENS
Role: SERF AUTHOR
Phone: (301) 614-6898
Fax: 301-614-5268
Email: Tyler.B.Stevens at nasa.gov
Contact Address:
NASA Goddard Space Flight Center
Global Change Master Directory
City: Greenbelt
Province or State: MD
Postal Code: 20771
Country: USA
Creation and Review Dates
SERF Creation Date: 2007-03-05
SERF Last Revision Date: 2012-04-24
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