Soil Parameter Estimation

Version: 2.1 (01/96)
Order No: BAS 14
Price: $50

SOIL estimates soil hydraulic properties using a nonlinear least-square analysis. Major input to the code includes pairs of measured water content and suction. The user can choose from the methods of Brooks and Corey (1964), Brutsaert (1966), Vauclin et al. (1979), and van Genuchten (1981) to estimate the soil-water characteristic function and the unsaturated hydraulic conductivity. The unsaturated hydraulic conductivity function is estimated by the series-parallel model of Childs and Collis-George (1950) and is obtained by straight-line fitting on a log-log curve. With the derived parameters, the program computes for selected pressures the observed and fitted moisture contents and the soil hydraulic properties. If saturated hydraulic conductivity is unknown the program provides an estimated value.

SOIL provides for interactive data entry and editing and includes graphical display of observed and fitted results of the soil-water characteristic function. The hydraulic conductivity function is fitted to a straight line on a log-log curve and "actual" and fitted results are compared graphically.

SOIL is a public-domain, DOS-based code, distributed with source code, executable image, and an internal example data set. Documentation includes user's instructions, theory, and a description of the example problems.


Intel 80i86 based computer, 640 Kb conventional RAM, DOS 3.0 or higher, VGA graphics; math coprocessor optional.

Author: A.I. El-Kadi (IGWMC).