1. General Model Information

Name: WETLANDS -2D flow and transport in variably saturated porous media

Acronym: WETLANDS


Main medium: terrestrial+aquatic
Main subject: biogeochemistry
Organization level: ecosystem
Type of model: partial differential equations (finite elements,2D)
Main application:
Keywords: soil water, unsaturated, flow, solute transport, richards equation, convection-dispersion equation, surface water, ponds, multiple root zones, evapoteranspiration, windows interface

Contact:

Dr. Stephen Bloom

Soil and Water Science Department
University of Florida
USA
Phone: (904) 528-6508 or (904) 392-7279
Fax:
email:sab@gnv.ifas.ufl.edu

Author(s):

VS2DT: R.W. Healy (U.S. Geological Survey)
WETLANDS: Stephen Bloom

Abstract:

Description
WETLANDS is a mathematical model for one or two dimensional water flow and solute movement in variably- saturated multi-layered porous media featuring optional surface water bodies (ponds) and multiple root zones. The model supports axially symmetric 2D systems (='pie slices') as an approximation to three-dimensional systems. Richard's water flow equation and the advective-dispersive equation are solved numerically using a finite-difference approximation and the interaction of water levels in the pond(s) with the surrounding soils are continually and dynamically adjusted. A Priestley-Taylor model is used to simulate evapo-transpiration by one to three plant species. Controlling parameters can be specified to track seasonal variation in sunlight, temperature, and rainfall. Solute transport can be affected by plant uptake, passive sinks, or a variety of sorption phenomena as well as by water transport in the soil and ponds.

Applications

WETLANDS is a useful tool to study water quality, groundwater contamination, remediation, waste disposal, groundwater recharge, drainage, subirrigation, transport into and from bodies of water, pond-soil-plant interactions, phytoremediation, and management practices.

Components

WET-PREP is a menu-driven, interactive preparation program that converts specifications into parameter files. WET-PREP features on-line help, graphical previews of data, and tests specifications to eliminate incompatible or erroneous simulation parameters. It also includes utilities for estimating parameters of water characteristic curves.

WETLANDS is a finite-difference model using the Strongly Implicit Method to simulate water and solute transport. WETLANDS is a descendant of VS2DT but has been extensively modified to support simulations of shallow systems featuring ponds (or lakes, rivers, etc.) with coupled evapotranspiration of multiple plant species. Output can consist of matrices of head (suction or total) and solute concentration, temporal traces of stream flow and solute concentration (from outlets associated with the ponds or from drains), mass balance monitoring, data-sets depicting the water table at any given time, data-sets formatted for input into contouring systems such as GEOEAS and TecPlot, and specialized reports . The model has been validated for a number of situations.

As a demonstration of the capabilities of WETLANDS, we have simulated two cases, one in which a locally concentrated contaminant is flushed from the soil into a pond, and one in which a contaminant in the pond is drawn into the soil by evapotranspiration.

WET-PLOT is a menu-driven, interactive visualization plotting program which provides data-manipulation, visualization, and publication-quality plotting tools. This is essentially the same plotting system provided in the Community Analyses System.

Source of the Abstract:
WETLANDS Home Page


II. Technical Information

II.1 Executables:

Operating System(s): MS Windows WETLANDS can be ordered from: Ecological Data Consultants, Inc. P.O. Box 760 Archer, FL 32618-0760 Costs are: $350.00 plus $10.00 for shipping A demonstration version is available for downloading. We recommend that you after you have downloadedthe file, you create a subdirectory, e.g., C:\WET, copy the file intothat subdirectory, and then run it. It will unpack itself into thecomponents of the demonstration system. If you encounter any problems,please feel free to use the e-mail link below to let us know.Be sure to read the README.1st file for an overview and a tutorial.

II.2 Source-code:

Programming Language(s): Fortran

II.3 Manuals:



II.4 Data:



III. Mathematical Information


III.1 Mathematics


III.2 Quantities


III.2.1 Input

III.2.2 Output


IV. References

The program VS2DT is documented in US Geological Survey WRI 83-4099 and 90-4025. Complete citations are
Lappala, E.G., Healy, R.W., and Weeks, E.P. 1983. Documentation of computer program VS2D to solve the equations of fluid flow in variably saturated porous media. US Geological Survey Water-Resources Investigations Report 83-4099.
Healy, R.W., 1990. Simulation of solute transport in variably saturated porous media with supplemental information on modifications to the U.S. Geological Survey's computer program VS2D. Water-Resources Investigations Report 90-4025.
Healy, R.W., 1987, Simulation of trickle irrigation, an extension to the U.S. Geological Survey's Computer Program VS2D: U.S. Geological Survey Water-Resources Investigations Report 87-4086, 61 p.
VS2DT is being used by personnel in several districts, as well as by scientists at various universities and consulting companies. An application is described in:
Mills, P.C., and Healy, R.W., 1993, Water and tritium movement through the unsaturated zone at a low-level radioactive-waste disposal site near Sheffield, Illinois, 1981-85: U.S. Geological Survey Water-Supply Paper 2386, 72 p.

V. Further information in the World-Wide-Web


VI. Additional remarks


Last review of this document by: T. Gabele: 21. 09. 1997 -
Status of the document:
Tobias Gabele Wed Aug 21 21:44:52 CEST 2002

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