The VS2DI package contains all the tools that a user needs to create, run, and view results for a simulation of flow and transport through variably saturated porous media. The package seamlessly integrates a graphical user interface--within which the user can draw the simulated domain and enter or modify model parameters--with existing USGS models of flow and solute transport, and a postprocessor that displays simulation results.

The VS2DI software package includes three applications:

VS2DTI: for simulation of water and solute transport
VS2DHI: for simulation of water and energy transport
VS2POST: a standalone postprocessor for viewing results saved from previous simulation runs

The numerical models used for flow and transport calculations are the U.S. Geological Survey's computer models VS2DT (for solute transport) and VS2DH (for energy transport). These models have been updated to version 3.2 for implementation in the VS2DI package.

Experienced users of VS2DT and VS2DH will find that it is now much easier to construct simulations and to analyze results.

Users unfamiliar with VS2DT and VS2DH will find that the VS2DI package allows for easy and rapid examination of water and contaminant (or heat) movement through various different hydrologic regimes. It is an excellent tool for hypothesis testing (for example, for looking at the influence that the shape, position, and hydraulic characteristics of a layer of low permeability have on the movement of a contaminant infiltrating from the soil surface). VS2DI is also very useful for teaching the basics of soil physics and subsurface contaminant transport. Typical applications of the programs are for studies of ground-water recharge, surface-water-ground-water exchange, and contaminant transport from waste disposal sites. An extensive on-line help manual provides all the information necessary to run the programs.

SYSTEM REQUIREMENTS

• Processor running at 200 megahertz or faster
• 64 MB memory or more, depending on size of problem
• 20 MB free disk space or more, depending on size of problem
  
• Windows 98 or higher
• display resolution of 800x600 or higher
• display color of 16 bit or higher

Author: R.W. Healy (U.S. Geological Survey)