Quoted from: https://wwwbrr.cr.usgs.gov/projects/GW_Unsat/vs2di/hlp/energy/vs2dh3p0.html 

VS2DH 3.0 is a computer program developed by the U.S. Geological Survey for solving problems of water flow and energy transport in variably saturated porous media. VS2DH 3.0 is a modification of the computer program VS2DT 3.0 for solving problems of variably saturated energy transport.

VS2DH originated as a standalone program that reads simulation setup data from input files, and writes simulation results to output files. Prior to the release of the present software, VS2DH was not designated by a version number, but will be referred to here as version 1.0. In revising VS2DH from version 1.0 to 3.0, no new features were added. Rather, the code was modified so that it can be run in an interactive manner, and the definition of the van Genuchten parameter "alpha" was revised to be consistent with established usage. The present software integrates VS2DH 3.0 with a preprocessor and postprocessor so that simulations can be run in a visual-interactive environment.

Major features of VS2DH 3.0 include the following:

• Use of finite-difference approximations to solve the Richard's equation for flow, and the advection-dispersion equation for transport.
• Simulated regions can be one-dimensional columns, two-dimensional vertical cross sections, or three-dimensional axially symmetric cylinders.
• Boundary conditions for flow include: specified pressure head, specified flux, infiltration with ponding, plant transpiration, bare soil evaporation, and seepage faces.
• Unsaturated hydraulic characteristics may be represented by: van Genuchten, Brooks-Corey, and Haverkamp equations, as well as tabular data.
• Transport processes include advection, dispersion, and conduction.

Users are strongly encouraged to obtain and read the following reports that document VS2DH and VS2DT:

Healy, R.W., and Ronan, A.D., 1996, Documentation of computer program VS2DH for simulation of evergy 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 90-4025, 125 p.

Healy, R.W., 1990, Simulation of energy 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 96-4230, 36 p.

Lapalla, 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, 131 p.