Computer program VS2DT solves problems of water and solute movement in variably saturated porous media. The finite difference method is used to approximate the flow equation, which is developed by combining the law of conservation of fluid mass with a nonlinear form of Darcy's equation, and the advection-dispersion equation. The model can analyze problems in one and two dimensions with planar or cylindrical geometries. There are several options for using boundary conditions that are specific to flow under unsaturated conditions: infiltration with ponding, evaporation, plant transpiration, and seepage faces. Solute transport options include first-order decay, adsorption, and ion exchange. The program is written in standard Fortran 77. Extensive use of subroutines and functions subprograms provides a modular code that can be easily modified for particular applications.
Healy, R.W., and Ronan, A.D., 1996, Documentation of computer program VS2DH for simulation of energy transport in variably saturated porous media -- modification of the U.S. Geological Survey's computer program VS2DT: U.S. Geological Survey Water-Resources Investigations Report 96-4230, 36 p., https://doi.org/10.3133/wri964230
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: U.S. Geological Survey Water-Resources Investigations Report 90-4025, 125 p., https://doi.org/10.3133/wri904025
Lappala, E.G., Healy, R.W., and Weeks, E.P., 1987, Documentation of computer program VS2D to solve the equations of fluid flow in variably saturated porous media: U.S. Geological Survey Water-Resources Investigations Report 83-4099, 184 p., https://doi.org/10.3133/WRI834099
This repository is provided as a courtesy. Modifications may have been made, e.g. to version strings, or syntax/language constructs for compatibility with modern compilers and build systems. Use this resource at your own risk; it should be regarded as provisional and not as an authoritative substitute for the official software release by the original authors.