This repository contains computer programs no longer under active development. The programs were developed over the years by the the U.S. Salinity Laboratory, USDA-ARS, Riverside, CA, in collaboration with the Department of Environmental Sciences of the University of California, Riverside. The programs all deal with various aspects of water and/or solute movement in the subsurface.
PDF versions of the program manuals are in the “docs” subdirectory.
U.S.: Public Domain
International: CC0
The following programs are in the repo:
CFITM: Fortran 77 program for determining equilibrium transport parameter from solute displacement experiments. [van Genuchten, 1980]
CFITIM: Fortran 77 program for determining nonequilibrium transport parameter from miscible displacement experiments. [van Genuchten, 1981]
CHAIN: Fortran 77 program for solving analytical solutions for one-dimensional solute transport involving sequential first-order decay chain reactions. Several examples illustrate the use of this program for problems involving the migration of radionuclide decay chains, or the simultaneous movement of various interacting nitrogen or pesticides species. [van Genuchten, 1985]
CHAIN_2D: Fortran 77 program for simulating two-dimensional variably-saturated water flow, heat movement, and the transport of solutes involved in sequential first-order decay reactions. The flow equation incorporates a sink term to account for water uptake by plant roots. The water flow part of the model can deal with prescribed head, gradient, and flux boundaries, as well as boundaries controlled by atmospheric conditions. The program considers free drainage boundary conditions as well as a simplified representation of nodal drains using results of electric analog experiments is also included. The heat transport equation considers transport due to conduction and convection with flowing water. The solute transport equations consider convectivedispersive transport in the liquid phase, as well as diffusion in the gaseous phase. The transport equations also include provisions for nonlinear nonequilibrium reactions between the solid and liquid phases, linear equilibrium reactions between the liquid and gaseous phases, zero-order production, and two first-order degradation reactions: one which is independent of other solutes, and one which provides the coupling between solutes involved in the sequential first-order decay reactions. The program may be used to analyze water and solute movement in unsaturated, partially saturated, or fully saturated porous media. [Šimůnek et al., 1994]
CXTFIT: Fortran 77 program for estimating solute transport parameters using nonlinear least-squares parameter estimation. The program may also be used to solve the direct or forward problem to determine the concentration as a function of time and/or position. Three different one-dimensional transport models are included: (i) the conventional equilibrium convection dispersion equation (CDE); (ii) the chemical and physical nonequilibrium CDE's; (iii) a stochastic stream tube model based upon the local-scale CDE, and assuming either equilibrium or nonequilibrium transport. [Toride et al., 1995]
SALT: Fortran 77 program for analyzing experimentally derived crop salt tolerance data. The program uses a non-linear least squares inversion method to find the unknown parameters in several salt tolerance response functions. One of the three models inlcuded in the program is the familiar piecewise linear response function. Application of this function leads to estimates for the salinity threshold and the slope of the response curve. Two alternative types of salinity response functions are also considered. [van Genuchten, 1983]
SWMS_2D: Fortran 77 program for simulating two- dimensional water flow and solute transport in variably saturated media. The program numerically solves the Richards equation for saturatedunsaturated water flow and the convection-dispersion equation for solute transport. The flow equation incorporates a sink term to account for water uptake by plant roots. The transport equation includes provisions for linear equilibrium adsorption, zero-order production, and first-order degradation. The program may be used to analyze water and solute movement in unsaturated, partially saturated, or fully saturated porous media. [Šimůnek et al., 1994]
SWMS_3D: Three-dimensional version of SWMS_2D. [Simunek et al., 1995]
3DADE: Fortran 77 program evaluating analytical solutions for two- and three-dimensional equilibrium solute transport. [Leij and Bradford, 1994]
N3DADE: Fortran 77 program evaluating analytical solutions for two- and three-dimensional non-equilibrium solute transport. [Leij and Toride, 1997]
Leij, F. J., and S. A. Bradford, 3DADE: A computer program for evaluating three-dimensional equilibrium solute transport in porous media, Research Report No. 134, U. S. Salinity Laboratory, USDA, ARS, Riverside, CA, 1994.
Leij, F. J., and N. Toride, N3DADE: A computer program for evaluating nonequilibrium three-dimensional equilibrium solute transport in porous media, Research Report No. 143, U. S. Salinity Laboratory, USDA, ARS, Riverside, CA, 1997.
Šimůnek, J., T. Vogel, and M. Th. van Genuchten, The SWMS_2D code for simulating water flow and solute transport in two-dimensional variably saturated media. Version 1.2, Research Report No. 132, U.S. Salinity Laboratory, USDA, ARS, Riverside, California, 196 pp., 1994.
Šimůnek, J., and M. Th. van Genuchten, The CHAIN_2D code for simulating two-dimensional movement of water flow, heat, and multiple solutes in variably-saturated porous media, Version 1.1, Research Report No 136, U.S. Salinity Laboratory, USDA, ARS, Riverside, California, 205pp., 1994.
Šimůnek, J., K. Huang, and M. Th. van Genuchten, The SWMS_3D code for simulating water flow and solute transport in three-dimensional variably saturated media. Version 1.0, Research Report No. 139, U.S. Salinity Laboratory, USDA, ARS, Riverside, California, 155 pp., 1995.
Toride, N., F. J. Leij, and M. Th. van Genuchten, The CXTFIT code for estimating transport parameters from laboratory or field tracer experiments. Version 2.0, Research Report No. 137, U. S. Salinity Laboratory, USDA, ARS, Riverside, CA, 1995.
van Genuchten, M. Th., Determining transport parameters from solute displacement experiments, Research Report No. 118, U. S. Salinity Laboratory, USDA, ARS, Riverside, CA, 1980.
van Genuchten, M. Th., Non-equilibrium transport parameters from miscible displacement experiments, Research Report No. 119, U. S. Salinity Laboratory, USDA, ARS, Riverside, CA, 1981.
van Genuchten, M. Th., Analyzing crop salt tolerance data: Model description and user's manual, Research Report No. 120, U. S. Salinity Laboratory, USDA, ARS, Riverside, CA, 1983.
van Genuchten, M. Th., Convective-dispersive transport of solutes involved in sequential first-order decay reactions, Computers & Geosciences, 11(2), 129-147, 1985.