GROUND WATER--Release of two computer programs for use with MODFLOW

In Reply Refer To:                       December 1, 1994
Mail Stop 411


Subject:  GROUND WATER--Release of two computer programs for
          use with MODFLOW

The purpose of this memorandum is to distribute documentation for
two new programs for use with the ground-water flow model,
MODFLOW.  We recommend that these reports be brought to the
attention of technical and management personnel concerned with
ground-water modeling studies.  Additional copies of the reports
are available from the Office of Ground Water.


MODPATH is a particle tracking program for use with MODFLOW;
MODPATH-PLOT displays the results from MODPATH.  The new
versions of MODPATH and MODPATH-PLOT add the ability to do
particle tracking for transient simulations.  In addition, the
graphical capabilities of MODPATH-PLOT have been significantly
enhanced.  For example, the ability to draw dipping and variable-
thickness layers has been added for cross sectional plots.

These programs are documented in Open-File Report 94-464,
"User's Guide for MODPATH/MODPATH-PLOT, Version 3:  A
Particle Tracking Post-Processing Package for MODFLOW, the
U.S. Geological Survey Finite-Difference Ground-Water Flow
Model" by David W. Pollock.


MFI is an interactive data input program for MODFLOW and
MODPATH.  MFI will run on the Data General workstations as well
as on personal computers.  Array data are entered by using
commercial spreadsheet software.  On Data General workstations,
the Tactician spreadsheet program is used.  By having one
program prepare data for both MODFLOW and MODPATH, duplicate
entry of the shared data is avoided.

MFI is documented in Open-File Report 94-468, "A Data Input
Program (MFI) for the U.S. Geological Survey Modular Finite-
Difference Ground-Water Flow Model" by Arlen Harbaugh.

Obtaining the programs

The Hydrologic Analysis Support Section (HASS) is handling the
distribution of MODPATH and MFI within the Water Resources
Division.  To obtain the programs for use on Data General
computers, connect to by anonymous ftp,
and change the current directory to pub/GW.  For MODPATH,
retrieve files mpath30.tar.Z and readme.mpath30.  For MFI,
retrieve files mfi.tar.Z and readme.mfi.  The readme files
contain instructions for installing the programs.  If there are
problems installing the programs, contact HASS by electronic
mail (wrdapp) or by telephone (Steve Regan 703 648-5896).

For those who may want to port MODPATH to other computers, a
generic version of the source code is available as Open-File
Report 94-463, "Source Code and Ancillary Data Files for the
MODPATH Particle Tracking Package of the Ground-Water Flow Model
MODFLOW--Version 3, Release 1" by David W. Pollock.  Note that
because MODPATH-PLOT is a graphical program, porting is not
generally easy.  A Graphical Kernel System (GKS) library is
required.  To obtain Open-File Report 94-463, contact
David Pollock by electronic mail (dwpolloc) or by telephone
(703 648-5007).

To obtain MFI for use on personal computers, contact
Arlen Harbaugh by electronic mail (harbaugh) or by telephone
(703 648-5615).

                             William M. Alley
                             Chief, Office of Ground Water

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