Vadose Zone Leaching Model, Version 2.2b Version: 2.2b June 1998, Thomas Harter, University of California, Davis Based on: Version (2.2a) updated by Rashid Islam (CDSI) in June 1996 (fixed the bugs in ground water impact calculations) Version (2.2) updated by Rashid Islam (CDSI) in October 1995 Modified exponetial constant in the Millington equation for calculating free-air diffusion coefficient from 10/3 to 7/3. Also corrected a bug in the Total ground water impact output. Version (1.0) of VLEACH developed by CH2M Hill for USEPA, Region IX, version updated by Varadhan Ravi (Dynamac Corp.) in March 1994 --------------------------------------------------------------------- Notes on Version 2.2b: This version (2.2b) updated by Thomas Harter (Dep. of Land, Air, and Water Resources, Univ. of California, Davis; thharter@ucdavis.edu). This version performs the identical computations to VLEACH version 2.2a, which I downloaded in May 1998 from EPA's Center for Subsurface Modeling Support (CSMOS) at EPA's Research Laboratory in Ada, Oklahoma. The differences to version 2.2a are the following: 1.The input file is different from the originial input files to make it easier to read the input data. The program cannot read the original input files (not upwardly compatible)! The input file is divided into three sections: general project information, contaminant information, and polygon information. The entire polygon section (including the initial concentration distribution subsection) must be repeated for each polygon. The format of each input line is: 40 characters (including blank spaces), number The format of the initial concentration profile information is: 40 characters,integer, comma, integer, comma, real number (no spaces) Be sure that the number starts on the 41st position of the line! An example input file is included. The easiest way to create an input file is to modify the example input file. Note that the input file MUST be named "vleach-input.txt" and must reside in the same directory as the program "vl22b.exe". I recommend that you always make a copy of your input file to another file. 2.The program has been modified to accomodate much larger columns. The program now accepts up to 9999 model cells. It is recommended to use a vertical cell size of 0.1 feet or less to reduce the amount of numerical dispersion to a minimum. The smaller cell size will generally require a time-step less than 1 year or even less than 1 day. The program has been altered to be able to handle time-steps as small as 0.0001 years. In earlier versions, time-steps smaller than one year caused output problems. The total time, gw impact output and profile output times must be exact multiples of the time-steps! The time-step should be small enough that the advective transport distance within one time-step is less than the cell thickness (Courant criterion). 3.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). The new output file is called "trnsprof.dat". For each polygon, it collects the profile information at each requested profile output time interval. The output is the concentration in the liquid phase (concentrations in the gas and sorbed phase are linearly proportional to the liquid phase, i.e. the shape of the profiles are identical in all three phases). The output under each polygon contains: 1st row: number_of_cells time0, time1, time2 .... endtime other rows: depth_of_center_of_cell conc(time0) conc(time1)... conc(endtime) (1 row per cell) This file can be imported into a spreadsheet as a space delimited file (with repeated spaces counted as one delimiter). By highlighting ALL rows below the first row (up to the next polygon), starting with the column containing the depth information, a x-y graph containing all the profiles can easily be created in the spreadsheet. Some programs will give a choice of "data in rows" or "data in columns". Since each column presents one profile (at a given time) the user should select "data in columns". Alternatively, if ALL rows below the first row are highlighted WITHOUT the first data column (which contains the depth information), and the user selects "data in rows", the result will be the breakthrough curves for each cell, beginning with the top-most cell. 4.The program was compiled for Windows95 and should run in Windows95 (tm), Windows NT (tm), and Windows98 (tm). The recommended minimum configuration is an Intel 486 compatible processor and at least 24 MB of memory (the program uses probably around 1 - 4 MB). 5.To run the program in Win95: start Windows Explorer find the file "vleach-input.txt" in your vleach working directory double-click on "vleach-input.txt" to edit the input file in Notepad(tm) click on FILE, then click on SAVE to save the input file. click "Start" click "Run" browse to find "vl22b.exe" double click on "vl22b.exe" click "ok" A window will briefly appear and disappear. Check the file "vleach.prm" to make sure that the input file was read correctly. 5.No warranties attached. You are using the program at your own risk. Please refer to the VLEACH manual published by EPA for details on VLEACH. Thomas Harter, June 29, 1998.