1. General Model Information

Name: Three-Dimensional Finite Element Model of Water Flow Through Saturated-Unsaturated Media

Acronym: FEMWATER


Main medium: terrestrial
Main subject: hydrology, biogeochemistry
Organization level: ecosystem
Type of model: partial differential equations (finite elements,3D), ordinary differential equations
Main application:
Keywords: water flow, saturated media, unsaturated media,hydrogeology,transport,wellhead protection area, richards equation, convection-dispersion equation, anisotropy, distributed sources/sinks, nonlinear adsorption isotherms, first order decay, finite element numerics

Contact:

CENTER FOR EXPOSURE ASSESSMENT MODELING (CEAM)
National Exposure Research Laboratory - Ecosystems Research Division
Office of Research and Development (ORD)
U.S. Environmental Protection Agency (U.S. EPA)
960 College Station Road
Athens, Georgia (GA) 30605-2700

Phone: 706/355-8400
Fax: 706/355-8302
email: ceam@epamail.epa.gov
Homepage: http://www.epa.gov/ceampubl/femwater.htm

Author(s):

G.T. (George) Yeh
The Pennsylvania State University
University Park, PA 16802
(original code)Robert Strobl
The Pennsylvania State University
University Park, PA 16802
(upgraded the code to EPA coding conventions) John Kittle
AQUA TERRA Consultants
Mountain View, CA 94043
(reviewed the code and suggested modifications)

Abstract:

Three-Dimensional Finite Element Model of Water Flow Through Saturated-Unsaturated Media (3DFEMWATER) and Three-Dimensional Lagrangian-Eulerian Finite Element Model of Waste Transport Through Saturated-Unsaturated Media (3DLEWASTE) are related and can be used together to model flow and transport in three dimensional, variably-saturated porous media under transient conditions with multiple distributed and point sources/sinks. These models can be used to apply the assimilative capacity criterion to development of wellhead protection areas, as each U.S. state is required to do under the 1986 Amendments to the Safe Drinking Water Act. The complexity of 3DFEMWATER/3DLEWASTE numerical models requires that they be used by experienced numerical modelers with strong background in hydrogeology. Both codes


The variable boundary condition in 3DFEMWATER simulates evaporation/infiltration/ seepage on the soil-air interface and in 3DLEWASTE, simulates mass infiltration into or advection out of the system. 3DLEWASTE contains options to model adsorption using a linear, Freundlich, or Langmuir isotherm, dispersion, and first-order decay. Femwater can be driven by the sophisticated (but rather expensive) graphic pre- and postprocessing enviroment GMS.


II. Technical Information

II.1 Executables:

Operating System(s): DOS, System requirements: self extracting DOS-executables, source-code, example data and extensive manual
The GMS-version of FEMWATER, a demo version of the graphic pre- and postprocessor GMS can be obtained from GMS Home Pages

II.2 Source-code:

Programming Language(s): FORTRAN(see Executables)

II.3 Manuals:

(see Executables)

II.4 Data:

(see Executables)

III. Mathematical Information


III.1 Mathematics


III.2 Quantities


III.2.1 Input

III.2.2 Output


IV. References

Yeh G.T., S. Sharp-Hansen, B. Lester, R. Strobl and J. Scarbrough 1992: 3DFEMWATER/3DLEWASTE: NUMERICAL CODES FOR DELINEATING WELLHEAD PROTECTION AREAS IN AGRICULTURAL REGIONS BASED ON THE ASSIMILATIVE CAPACITY CRITERION Office of Research and Development, Environmental Protection Agency, Athens, GA. EPA/600/R-92/223 278 pp.(included in self extracting DOS-executables and Manual)
U.S. Environmental Protection Agency. 1987. Guidelines for Delineating WellheadProtection Areas. EPA No. 440/6-87-010. Office of Groundwater Protection,U.S. Environmental Protection Agency, Washington, DC. NTIS No. PB88-111430-AS.
U.S. Environmental Protection Agency. 1989. Transport and Fate of Contaminants in theSubsurface: Seminar Publication. EPA/625/4-89/019. Center for EnvironmentalResearch Education, U.S. Environmental Protection Agency, Cincinnati, OH.

V. Further information in the World-Wide-Web


VI. Additional remarks


Last review of this document by: J. Bierwirth: 6.04.2001 -
Status of the document:
last modified by Tobias Gabele Wed Aug 21 21:44:42 CEST 2002

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