RETC
RETC for Windows
December 1998, Version: 6.xx
Authors:
M.Th. van Genuchten, J. Simunek, F. J. Leij, M. Sejna
Reference:
van Genuchten, M. Th., F. J. Leij, and S. R. Yates. 1991.
The RETC Code for Quantifying the Hydraulic Functions of Unsaturated Soils, Version 1.0. EPA Report 600/2-91/065, U.S. Salinity Laboratory, USDA, ARS, Riverside, California. (Download PDF, 2.1Mb)
The Program
RETC Main Window - Input data
Output - Soil Hydraulic Properties RETC is a computer program which may be used to analyze the soil water retention and hydraulic conductivity functions of unsaturated soils. These hydraulic properties are key parameters in any quantitative description of water flow into and through the unsaturated zone of soils. The program uses the parametric models of
- Brooks-Corey (1964),
- van Genuchten (1990), (Download PDF)
- the lognormal distribution model of Kosugi (1996), and
- the dual-permeability model of Durner (1994)
to represent the soil water retention curve, and the theoretical pore-size distribution models of Mualem (1976) and Burdine (1953) to predict the unsaturated hydraulic conductivity function from observed soil water retention data The program comes with a manual which gives a detailed discussion of the different analytical expressions used for quantifying the soil water retention and hydraulic conductivity functions. A brief review is also given of the nonlinear least-squares parameter optimization method used for estimating the unknown coefficients in the hydraulic models. The RETC program may be used to predict the hydraulic conductivity from observed soil water retention data assuming that one observed conductivity value (not necessarily at saturation) is available. The program also permits one to fit analytical functions simultaneously to observed water retention and hydraulic conductivity data. Several examples are presented to illustrate a variety of program options.
The program comes with a user manual giving detailed information about the computer program along with instructions for data input preparation and listings of sample input and output files. A listing of the source code is also provided. .
System Requirements:
Intel Pentium or higher processor, 16 Mb RAM, hard disk with at least 20 Mb free disk space, VGA graphics (High Color recommended), MS Windows 95, 98, NT, 2000, XP
The RETC software was designed for Windows XP and we do not guarantee its compatibility with newer Windows systems (e.g., Win10, 64 bit)
Online Help: The RETC online help has been written in the hlp format. Microsoft decided not to support the hlp format in its latest versions of Windows (Vista, 7, 10; see link). Since RETC is such a simple program (which people should be able to use without help), we have decided not to put an effort in converting the help into a new help formats (e.g., chm, html, xml). We refer the RETC users to the technical manual (Download PDF, 2.1Mb).
Support and Links
The RETC is available as a public domain program. PC-Progress provides the following free support services for this software:
Other interesting links: