Introduction to Vadose Zone Hydrology & Modeling
Modeling Materials Developed for
"Introduction to Vadose Zone Hydrology & Modeling"
VLEACH is a one-dimensional, finite difference model for making preliminary assessments of the effects on ground water from the leaching of volatile, sorbed contaminants through the vadose zone. The program models four main processes: liquid-phase advection, solid-phase sorption, vapor-phase diffusion, and three-phase equilibration. In an individual run, VLEACH can simulate leaching in a number of distinct polygons, which may differ in terms of soil properties, recharge rates, depth of water, or initial conditions. Modeling results in an overall, area-weighted assessment of ground-water impact (cited from the EPA website). The original version can be found at the EPA website:
An updated, more user-friendly version is available here. Simply double click on the file below and your browser should ask you where you want to save the file for download.
This version of VLEACH (version 2.2c) has been modified from the EPA version:
- The input file is more user friendly
- The program now accepts up to 100,000 model cells. Time steps can be as small as 0.0001 years. with up to 500 output times.
- A new transient profile output file is created to allow for easy plotting in spreadsheet programs such as Microsoft Excel(tm), or Corel Quattro Pro (tm).
- This version has been compiled for Windows XP (April 2006). Please use vleach11b.zip for older versions of Windows (maximum of 9,999 model cells).
The files include the following:
vl22c.exe (executable code, 300KB)
vlch22c.for (FORTRAN source code, 28KB)
vleach-input.txt (sample input file, 3KB)
vleach.prm (sample output file, 25KB)
vleach.out (sample output file, 30KB)
vleach.prf (sample output file, 286KB)
gwimp.dat (sample output file, 313KB)
soilimp.dat (sample output file, 15KB)
trnsprof.dat (sample output file, 83KB)
readme.txt (readme file, 7KB)
VLEACH.pdf (EPA's VLEACH manual, 348KB)
This zip-file contains all of the above (for Windows XP):
vleach22c.zip (pkzip file, 552KB)
This zip-file contains an older version compiled on Windows'95:
vleach22b.zip (pkzip file, 142KB)
This is a pedotransfer function program to predict soil water retention and unsaturated hydraulic conductivity from basic soil properties (texture, bulk density, etc.). Here, a unique dataset consisting of about 310 soil water retention and unsaturated hydraulic conductivity functions is presented, with hydraulic data obtained using the multi-step outflow method. Using neural network analysis, soil water retention and hydraulic conductivity characteristics are predicted from basic soil properties, i.e., sand, silt, and clay content, bulk density, saturated water content, and saturated hydraulic conductivity. Because the training data sets consists of soil hydraulic data that are obtained using the same measurement technique, hydraulic property predictions improved significantly when compared to predicted hydraulic functions using the program Rosetta.
Minasny, B., Hopmans, J.W., Harter, T., Eching, S.O., Tuli, A., Denton, M., 2004. Neural networks prediction of soil hydraulic functions from multi-step outflow data. Soil Science Society of America Journal 68, 417-429. (pdf file for personal use only)
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