U.S. Geological
Water Resources Applications Software

Ground Water || Surface Water || Water Quality || General

Summary of MODFLOW-GUI

       modflow-gui - Preprocessor and postprocessor graphical-user
                     interfaces for preparing MODFLOW-2005, MODFLOW-2000, MODFLOW-96, MOC3D, MODPATH,
                     and ZONEBDGT input data and viewing model output for 
                     use within Argus Open Numerical Environments (Argus ONE)

This report documents a new version of the MODFLOW Graphical User Interface
for Argus ONE (MODFLOW GUI) that adds support for the U.S. Geological Survey's
MODFLOW-2000 and the Reservoir, Transient Leakage, Interbed Storage, Lake, and
Gage packages. The new version can also import existing MODFLOW-88 and
MODFLOW-96 models. A utility program, GW_Chart, was developed in conjunction
with the MODFLOW GUI and is used for post-processing of the output of MODFLOW.
Also, in conjunction with the development of the MODFLOW GUI, three utility Plug-In
Extensions (PIE's) were developed. One PIE facilitates importing gridded data into
Argus ONE. This is helpful when attempting to reproduce an existing model in Argus
ONE. Another PIE allows editing of data points on data layers. A third utility PIE
allows expressions to be evaluated at specific X,Y coordinates. A series of example
models were created and can be used to learn about the features of MODFLOW, Argus

Note: The Argus ONE interface only works with MODFLOW-2005, MODFLOW-2000, MODFLOW-96
and not with earlier versions of MODFLOW.

MODFLOW-GUI supports the following packages: BAS5, BAS6, BCF5, BCF6, LPF, WEL5,
RIV5, DRN5, GHB5, RCH5, EVT5, SOR5, SIP5, PCG2, DE4, STR1, HFB1, HFB6, FHB1, IBS1, RES1, TLK1,

The following capabilities are NOT yet supported:

HISTORY 13/11/29 Fixed bug that caused Argus ONE to crash when being
MODFLOW GUI now writes the observation files in the format
used by MODFLOW-2005.
In the select MT3DMS files dialog box, the edit boxes for
the file names were not being set to right color to
indicate whether or not the file exists. 12/04/20 Fixed bug in checking ending time for MODPATH.
MODFLOW GUI now exports SURFDEPTH in Lake package.
Fixed bug exporting MT3DMS TOB package.
Fixed problem with importing data on systems in which the
decimal character is not a period. 11/09/26 Added support for State variables in MODFLOW-GWM
Changed warning messages for drains.
Changed extension for MT3D mass budget summary.
Fixed bug in exporting Seawat variable density file.
Fixed bug exporting SFR when no other packages were
Fixed bug that caused unused parameters to be created with
the SFR package.
Fixed bug in importing MODFLOW quaisi-3D models with more
than one non-simulated layer.
Fixed import of BCF transmissivity from existing MODFLOW
Fixed bug in editing PERLEN and TSMULT in DIS package.
Fixed bugs that could incorrectly cause error messages to
be generated when editing the stress period data.
Fixed bug in exporting MNW2 data when the steady-state
option was selected.
Fixed reading water table with binary files.
Fixed bug with specifying Output control.
Fixed reading double-precision budget files. 11/03/17 Fixed bug that caused a range check error when generating
the MNW2 input file.
Fixed bug that caused the variable P always to be exported
as zero in the MNW2 input file.
Fixed bug that caused access violations if the MNW2 input file
was exported without also exporting the DIS file. 11/02/28 When importing heads from the model results, you can now
also import the water table.
Fixed a bug that caused the MODFLOW Observations file and
the GWT observations file to have the same unit number.
Added additional error checking when exporting the MNW2
input file.
Fixed a bug that would sometimes cause access violations. 11/01/21 When exporting the General Head Boundary input file
when MF2K-GWT is active, IFACE is now always included in the options.
This is a work-around for what appears to be a bug in MF2K-GWT. 10/12/06 The real-world coordinates of the 4 corners of the grid and
the grid angle are now listed as comments at the beginning
of the discretization file. 10/09/02 Fixed export of custom particle locations in GWT.
Fixed bug that caused export of MNW1 to fail when a geologic
unit has a vertical dicretization greater than 1.
Fixed bug that caused the export to terminate with an error
if a multiplier constant was used in a multiplier function.
Added support for time-varying lake leakance.
Fixed bug that sometimes allowed a global file to be
included in the name file for MODFLOW-2005.
Fixed bugs related to the SWT package. 10/01/07 Added support for the MNW2 package.
Fixed bug in determining precision of budget files. 09/10/05 Fixed bug that made exporting models very slow if the model
included both head observations and hydraulic conductivities
in the LPF package set by parameters. 09/09/17 Fixed bug in writing the Variable Density Flow package input file for SEAWAT.
Allowed mixed upper and lower case in file names
Allowed long file names for MODFLOW-2000 and MODFLOW-2005
Fixed bug in backwards particle tracking
Fixed bug with heat transport in SEAWAT
Fixed bug in well export
Fixed bug in exporting IBOUND in MODPATH when the RES or LAK packages are used.
Used temp files when exporting multiplier or zone arrays 09/03/09 Added support for reading binary files created by the
double-precision version of MODFLOW-2005.
Added support for the kinematic routing option in the SFR
Fixed bug in export of the MNW package when MT3DMS is active.
Fixed bug in export of GWM decision variables. 08/09/22 Added support for HUF and UZF package to be used simultaneously.
Fixed bug exporting head observations.
Added support for creating CSV and CSV2 files with ZoneBudget. 08/07/08 Added export of SURFDEP parameter in UZF package.
Added support for CONSTANTCV and NOCVCORRECTION options
in the MODFLOW-2005 LPF package.
Removed dependance on MF_Layer function.
Added support for SEAWAT 4.0 Viscosity package.
Added support for MT3DMS head concentration observations. 08/05/12 Fixed bugs that prevented any flow package other than the
BCF package from being used with MODFLOW-2005. 08/04/02 Added new checkbox to Advanced Options tab that is helpful
for working with the LGR process.
Fixed bug in which the elevations of non-simulated layers
of imported models were not set correctly.
Fixed bug in export of stream observations.
Fixed bug in reading budget terms.
Added support for undocumented options in MNW packages.
Fixed bugs in export of UZF input.
Added work-around for bug in the HUF package.
Fixed bug in assigning unit numbers.
Fixed bug in exporting MODPATH with MODFLOW-2005.
Fixed bug in importing parameter names.
Fixed bug that prevented IFACE from being stored in the
budget file.
Fixed bug in exporting gages in the UZF package. 07/06/12 Added support for SWT package.
Added support for MT3DMS 5.2
Fixed bugs in importing existing models.
Fixed bug exporting observations when sensitivity process
is not used.
Fixed error message.
Fixed bug in export of SUB package input. 07/06/12 Added support for MODFLOW-2005 and the UZF package.
Fixed bugs in importing existing models. 07/04/10 Fixed bug in exporting IRCH in Recharge package.
Modified FlowReader.dll to read budget files generated
when IRCH is incorrectly s et to 0.
Change to store initialization data in ApplicationData
folder. 07/03/19 Fixed bug exporting Well package input when parameters
with multiple instances were used.
Fixed bug deleting Multiplier arrays.
Fixed bug exporting HYDMOD input file when parameters
were used in the STR package.
Fixed bug exporting boundary conditions using only
contours. 07/01/11 Fixed bug importing IEVT and IRCH from existing MODFLOW
Improved method of importing ._b files.
Fixed bug importing parameter values from existing
MODFLOW models. 06/11/15 Fixed bug in export of GWM input.
Fixed bug in export of SFR input.
Added option to disable stream observations.
Fixed bug in export of FHB input.
Fixed bug in resetting MNW expressions. 06/09/26 Fixed bug in export of MODPATH input files when using
elevations to restrict input.
Fixed bug in export of DAFLOW input.
Added support for new options in MODFLOW-GWM version 1.1.
Added support for SFR2 package.
Added support for new options in GMG package in
MODFLOW-2000 version 1.17.
Added support for new options in SUB package in
MODFLOW-2000 version 1.17.
Added support for new options in LAK package in
MODFLOW-2000 version 1.17.
Added support for ALLFILES option in Observation package.
Fixed bug in Expression for "Multinode Wells.Last Unit." 06/08/23 Help system converted to HTML HELP.
Fixed bug in export of GWT particle observations.
Added new parameter to Multi Node Wells for particle
Fixed bug in importing CHD data from existing models.
Improved efficiency of exporting area wells with the
alternative export template.
Fixed access violation bug in exporting area wells with
Fixed bug importing recharge option code.
Fixed display of "Resan-2000" on Run dialog box.
Fixed bug in reading the number of HFB parameters.
Fixed bug adding HUF parameters.
Fixed bug in export of MT3DMS SSM.
Fixed bug in export of MODPATH input when elevations
used to control particle placement.
Fixed bug in calculation of area of intersection between
a contour and a block. 06/05/16 converted to using allocatable arrays when importing
MODFLOW-96 models. Added support for compatiblility
between ELLAM and AGE packages in GWT. Added support for
PRTP, PTOB, CBDY, SSTR, and MNWO input files in GWT
version 1.9. Added support for MNW package in SEAWAT.
Fixed bug in evaluation of Horizontal Flow Barriers.
Improved method of assigning unit numbers to files.
Improved speed when importing models. Fixed bug in
reading flow budget files. (First layer was skipped.)
Added new option to restrict MODPATH particles using
elevations. Added option to control the printing of
heads and flows in the HUF package. 05/12/06 Added support for Ground-Water Management process (GWM).
Added support for Multi-Node Well Observation package
(disabled pending release of Multi-Node Well Observation
package ). Added support for importing HFB package into
MODFLOW-2000 models. Improved importing MODFLOW-2000
models. Fixed bug in export of STR package. Fixed bug
in export of MT3DMS input. Fixed bug in export of several
boundary condition package input files. Fixed bug
importing EVT, ETS, and RCH packages. Fixed bug in
exporting IBS package. Fixed bug in BlockList PIE. Fixed
bug exporting FHB package. 05/08/04 Added support for importing the CHD package input from
MODFLOW-2000 models. Improved efficiency when doing post-
processing with MODPATH output. Fixed bug that kept
MODPATH from reading MODFLOW output files correctly.
Fixed bug that kept MODPATH from being run from the
MODFLOW-GUI. 05/07/28 Added support for PRINTTIME option in MODFLOW. Added
support for automatically opening output files in
Notepad after completion of model. Fixed bug in EVT and
ETS that caused it to set the layer number to zero for
inactive cells. Fixed bug in importing MODFLOW-2000 model.
Fixed bug in checking HUF parameters. Fixed bug involving
USE checkbox for the MNW package. Fixed bug in evaluation
of HUF geometry. Added additional options for specifying
Output Control frequency. Fixed bug in specifying output
format for HUF package. Added support for reading binary
files created by HUF package. Fixed bug in format
specification for formatted output files. 05/04/12 Fixed bug in reading files in which SEAWAT is selected
and area layers for certain boundary conditions were
not present. Fixed bug in evaluating IFACE for the BFLX
package in MF2K-GWT. Fixed bug in attempting to add
parameters to layers that don't exist. Fixed bug that
could cause access violations if parameters were
incorrectly defined in the SFR package. 05/01/31 Fixed Expression for "MODFLOW FD Grid.Gen Head B Location
Unit[i]". Fixed error in attempting to export the CHD
package input in some cases where CHD is not used. Fixed
bugs in evaluation of Area Drains, Area GHB', Area CHD's
and Area Drain Returns. 04/11/22 When opening an existing model that uses MT3DMS, the
Expressions for the following parameters on the
MODFLOW FD Grid layer are updated:
MT3D Initial Concentration Unit[i],
MT3D Initial ConcentrationB Unit[i],
MT3D Initial ConcentrationC Unit[i],
MT3D Initial ConcentrationD Unit[i], and
MT3D Initial ConcentrationE Unit[i].
The expressions are changed so that they would refer to
the concentration parameter rather than the Mass parameter
that was used prior to verions Users may wish
to create expressions for the concentration parameter.
Fixed postprocessing of GWT vectors when multiple layers
are selected. Speeded up importing o f existing MODFLOW
models. Fixed memory leak in MT3DMS export. Users can
specify the format in formatted head or formatted drawdown
files. Fixed bug in checking confined storage in the BCF
package. Fixed bug in export of CINFL in GWT. Fixed bugs
in postprocessing of starting times in MODPATH output.
Added support for Weighted Particles option in GWT but
disabled it pending release of an updated version of GWT.
Increased efficiency when importing existing models or
postprocessing for MODPATH. Fixed bug in postprocessing
GWT velocities. Fixed bugs in export of Advection
Observations when the vertical discretization of a unit was
greater than 1. Fixed bug in export of Simple Reactions
package for GWT. Fixed bugs in adding layers and parameters
in the Simple Reactions and Double Porosity packages in GWT.
Fixed bug in evaluating lake leakances. 04/09/23 Added capability of disabling a specific observation layer
without removing it. Added capability of specifying MODPATH
BeginPeriod, BeginStep, EndPeriod, and EndStep using
absolute times. Added additional error checking when the
LPF package or GWT is used. Fixed a (harmless) bug when
reading old files. Fixed bug in calculating HK array for use
with Observation Wells. Added support for weighted particles
in GWT. However, this feature is disabled pending release of
the updated version of GWT. Fixed bug in export of the
GWT input file. Fixed bug in export of SFR input file when
GWT is used and there are multiple stress periods. Improved
efficiency in exporting GAGE package input file. Fixed
expression for GHB Location Unit[i] parameter. 04/08/20 Fixed bug that caused MODPATH input files to sometimes use
the tab character as a delimiter. Fixed bug in export of
LPF input files which caused the HK array to be labelled
with a comment identifying it as HY instead of HK. Added
support for the GMG solver. Fixed bug introduced in which caused the River Location[i] and Drain
Location[i] parameters on the MODFLOW FD Grid layer to
have incorrect expressions in models generated with prior
verisons of the MODFLOW GUI. Fixed bug that could cause
the layer allocations for multi-layer observation wells to
be calculated incorrectly when the Sensitivity package was
used. Fixed bug in export of stream observations. Added
support for importing the HFB package from MODFLOW-96
models. Increased X-Array dimension when importing
MODFLOW-96 models. 04/07/30 Fixed bugs with deletion of Multiplier and Zone layers.
The methods for exporting the River, Drain, Drain Return,
and General Head Boundary packages were modified to allow
the user to specify conductances directly. In conjuction
with this change the "Conductance" parameter is renamed
the "Conductance Multiplier" parameter. Various bugs
related to MT3DMS have been fixed. The layers "MT3D Point
Constant Concentration Unit[i]" and "MT3D Area Constant
Concentration Unit[i]" have been eliminated. Their
function is now provided by the layer "MT3D Time Varying
Constant Concentration Unit[i]". The "Mass" parameter
on the layer "MT3D Point Initial Concentration Unit[i]"
has been replaced by a "Concentration" parameter. Support
for SEAWAT-2000 has been added. 04/07/01 Fixed bug importing MODFLOW-2000 models in which zone
array or multiplier array input files were included in
the model but no zone arrays or multiplier arrays were
included in the model. Fixed bug in importing MODFLOW-
2000 models that included the HUF package. Fixed
import of MODFLOW-2000 models in which parameter names
contained hyphens. Fixed bug in exporting the BCF
package in MODFLOW-2000 that could cause a range check
error. Added support for SFR1 package. 04/04/21 Fixed bug reading data from MFGUI files older than
version 4.0. Fixed bug in export of prescribed
concentrations with MOC3D. Fixed bug that incorrectly
warned of confined storage coefficients less than or
equal to 0 in unconfined layers in the BCF package in
MODFLOW-2000. Updated Utility PIE. 04/04/01 Check boxes have been added to the Advanced Options tab.
They can be used to change the way certain boundary
conditions are evaluated. In models created with prior
versions of the MODFLOW GUI, they will be unchecked to
preserve backwards compatibility. In new models, they will
be checked. The checked state is recommended. For a
complete explanation see the help file. A problem in
using Argus ONE and a workaround for it has been added to
the help file. The version history has been amended to
change version to so as to match the
version number actually displayed in the program. The SFR
package, which had been incorrectly enabled in version, has been disabled pending release of the SFR
package. 04/03/22 Fixed bug in importing MODFLOW-96 models. Fixed bug in
exporting data for MODPATH with MODFLOW-2000. 04/02/02 Updated Lake package export to reflect changes incorporated
in MODFLOW-2000 version 1.13.00. Fixed bug in import of
vertical conductance in the BCF6 package in MODFLOW-2000.
Fixed bugs in import of recharge and evapotranspiration
rates from MODFLOW-2000 models. Added alternate export
template for Stream package. 03/12/09 Added capability of importing FHB package when importing
MODFLOW-2000 models. When importing models, the default
interpolation method for new layers containing imported
data has been changed from "Default" to "QT_Nearest." 03/12/02 Fixed bugs in import of MODFLOW-2000 models. Added
capability of importing head-observations during import of
MODFLOW-2000 models. Added capability of importing HUF
package when importing MODFLOW-2000 models. 03/10/28 Added new command: "PIEs|Link Streams..." that allows the
Downstream Segment parameter to be set based on the
proximity of streams in the S tream Package. Added support
for the Subsidence and Aquifer System Compaction Package.
Fixed a bug importing MODFLOW-2000 models. 03/09/30 Added support for new options in HUF2 package as described
in Open-File Report 02-409 and Open-File Report 03-347.
Added support for specifying porosity via parameters in
ADV2 package. Added check that when the ADV2 package is
used, the first stress period is steady-state and all
other stress periods are transient. Fixed a bug in
importing MODFLOW-2000 models. 03/09/12 Disallowed usage of the Advection Observation package
with the BCF package because of restrictions in MODFLOW
on using the two together. Removed source code for the
Algebraic multigrid solver from modflw2000.dll. Fixed
import of IOUTAMG from the LMG solver. Updated export
of HUF package to be consistent with import format of the
HUF2 package (without, however, supporting any of the new
capabilitites of the HUF package). 03/09/08 Fixed bug that caused a separate budget file for the MNW
package to be included in the MODFLOW-2000 name file even
when that file was not used. SelectChar.exe was modified to
allow the user to specify Virtual Key codes. To do so, use
Vk-(value) where value represents the number of the virtual
key code. For example, to specify the up arrow, use Vk-38
and to use the down arrow use Vk-40. Other virtual key
codes can be found in the Windows programmers documentation.
The ReadFileValue PIE was modified to Beep when the value
associated with a key is not properly formatted so that it
can be converted to a real number. In name file, binary
data files now use the "OLD" or "REPLACE" options. Several
memory leaks eliminated. Added support for the the BFLX
package in GWT. Fixed bug that would sometimes cause the
combo box used to select the model units for the stream
package to become disabled or enabled incorrectly. Fixed
bug in export of Drain package when parameter instances are
used. Added support for importing MODFLOW-2000 models. 03/06/09 Fixed bug that prevented export of model input files. 03/06/06 Corrected spelling errors. Fixed bug in export of Lakes
package when a rotated grid was used. Added labels to
LPF input file. Fixed bug in links to the help file.
Added "ObjectName" parameter to Observations. It is used
to set the default for observation names when there are
more than one observation for an object. Changed the
allowed number of characters in Advection Observation
names from 4 to 12. Added Starting Row and Starting
Column parameters to MODPATH pathline postprocessing
layers. The MODFLOW GUI can now periodically check the
Internet to see if a new version of the MODFLOW GUI has
been released. 03/04/18 Updated installer to include MODFLOW-2000 version 1.11. 03/04/15 Fixed bug in export of FHB package input files for
MODFLOW-2000 when closed contours were used to define
the specified flux. Fixed inconsistency between export of
FHB input files between MODFLOW-2000 and MODFLOW-96 when
closed contours were used to define the specified head.
Fixed bug in export of MODPATH particle location file.
Added support for MNW package. Fixed broken links in help
file. Changed "Reference Stress Period" parameter to vary
with time. Fixed bug in export of stream observations that
could cause some stream observations to be exported even
if the time for the observation was 0 and reference stress
period for the observation was 1. When exporting MODPATH
input files, they can now choose to skip exporting the
main input file, the particle file, or both. Added suport
for DAFLOW package. Added a new post-processing option
that allows you to plot water budget terms for individual
cells. Added SHOWPROGRESS option introduced in MODFLOW-2000
version 1.11. 03/02/24 Fixed bug in Blocklist PIE that could cause export of
Horizontal Flow Barriers to skip barriers located in the
last row or column. Added new parameter "Reference
Stress Period" that allows users to set IREFSP in
observation process input files to values other than 1.
Fixed bug in import of MODFLOW input files that caused
it to require that all package names be in uppercase.
Added option to import of MODFLOW input files to convert
input files from UNIX-style line terminators to DOS-style
line terminators. Added additional error checking for
head and flux observations and for LPF package. Deleting
a parameter also deletes that parameter from the
Sensitivity Analysis. 03/01/28 Added additional error checking when exporting MODPATH.
Included updated version of Utility PIE. Fixed bug in
export of Reservoir package input. 03/01/10 Fixed bug introduced in version in export of
Reservoir package with a rotated grid. 03/01/09 Added new command: "PIEs|Import MODFLOW Contours from
Spreadsheet..." Fixed bug in export of Reservoir package
with a rotated grid. Fixed bug in specifying the number
of layers for advection observation starting points. 02/12/23 Added buttons to make deleting parameters easier. Fixed
incorrect error message regarding abscence of specific
yield parameters in the LPF package for confined units.
Added notice when using LMG solver. Changed
postprocessing to allow creation of multiple layers at
one time. Fixed bug in export of IBS package under
MODFLOW-2000. Fixed bug in postprocessing of IBS package
under MODFLOW-2000. 02/10/17 Added additional error checking: the GUI now checks that
zone numbers have been assigned to parameter clusters
for which a zone array has been specified. Fixed bug that
prevented observations of flux and prescribed head
boundaries from being used. Added buttons to either save
as an image or print the display of the horizontal flow
barriers to the dialog box displayed in the command
"PIEs|Display Horizontal Flow Barriers". Changed warning
message that is displayed when an out-of-date version of
Argus ONE is used. Changed the error handling that occurs
when the MF_Layer function is evaluated in an invalid
context so that a warning dialog box is displayed only
once. 02/09/27 Added new option for post-processing of MODPATH endpoints;
Endpoints can now be plotted at their starting locations.
This can be helpful when delineating recharge areas. 02/09/12 Fixed bug in assigning layers to multi-layer observations
at the edge of the grid. Fixed size of Decay Calculator
dialog box for GWT. Disabled printing of particles file
when using ELLAM in GWT (because ELLAM doesn't use
particles). Fixed export of NSTP when it is larger than
99999 in the Basic package for MODFLOW-96. Updates to
help system. 02/08/23 Fixed bug in changing from time-varying to steady stress
for stress packages. Updated online help. Added additional
error checking. 02/08/05 Changed interpretation of HUF layers from "Nearest" to
"624 Interpolation." Fixed some typographical errors.
Fixed bug in printing of Observation names. Fixed checking
of specific storage and specific yield in the BCF package.
Added support for new options in the Gage package in
MODFLOW-2000 version 1.9. Fixed bug in calculation of initial
head when the expression for the prescribed head is not set
to $N/A. 02/06/04 Fixed bug in calculating vertical conductance if the
vertical hydraulic conductivity is 0. Added additional
error checking. 02/05/20 Fixed bugs in reactivation of stream package and export of
specific yields in LPF package. 02/05/20 Fixed bug with exporto of LAYWET with LPF package. 02/05/20 Fixed problem with deleting geologic units when the GWT
process is active. 02/05/08 Added warning messages when exporting Observation files
with no observations or Sensitivity files with no
parameters. Added support for creating extra files needed
by Model Viewer for MODFLOW-96 and MOC3D models. Fixed
bug that would cause incorrect values for the number of
cells and number flux observations if the number of cell
groups was 0. Added additional error checking for HUF and
Lake packages. Locked the evaluation method on the Lakes
layer. Fixed bug that caused the table in which the FHB
times were entered to be gray even though the data could be
editted. Fixed bug that caused access violations if the
number of times for the FHB package was increased and then
the Cancel button was pressed. Added support for LMT
package and MT3DMS. Added support for NOPRINT option in
RIV, GHB, DRN, DRT, HFB, WEL, and CHD packages. 02/03/18 Fixed evaluation of number of MOC3D observation when
the MOC3D observation well file is not exported. Updated
error message with MODPATH postprocessing. Improved
handling of invalid parameter name specification. 02/02/28 Fixed bug in expression of the grid parameter used to show
locations of CHD boundaries. 02/02/27 Fixed bug in export of CHD input file when the GWT
process is used. 02/02/25 Changed expression for Diffusion Coefficient parameter
on the Horizontal Flow Barrier Unit[i] layer to match
the diffusion coefficient specifed in the general GWT
process. Fixed bug in export of MODPATH input for
models with large numbers of layers. Added support for
the Hydrogeologic-Unit Flow package. 02/02/12 Added warning about Compact Budget option for budget file
and Zonebudget. Added CHD package. Changed default solver
back to PCG2. Changed the way models are started so the
Argus ONE can be closed without closing the model first.
Added code to generate valid unit numbers for all input
files even if the model was saved with invalid unit numbers.
Enhanced error checking. Fixed bug in export of variance-
covariance array in flow observations. Fixed problem with
running the MODFLOW GUI on systems in which the decimal
separator is not a period. Added CHFB package for the
Ground-Water Transport process (GWT). 02/01/17 Fixed bug in export of option to create new budget file.
Fixed bug that lead to loss of model description.
Corrected units for concentration parameter. Removed
extraneous "Cell Group" parameter from the layers for the
Well package. Fixed access violation with prescribed-head
flow observations. 01/12/18 Fixed bugs relating to DRT package. Added support for
time-varying parameters in MODFLOW-2000 version 1.7.
Added Utility PIE as a replacement for several obsolete
PIEs. 01/11/02 Fixed bugs with creating and reading endpoint files in
MODPATH. 01/11/02 Fixed bug with export of BCF package with MODFLOW-2000.
Fixed bug with failure to automatically suggest exporting
Drain package input file when a model is reopened. Fixed
bugs in the alternate export templates for export of
wells, rivers, and general-head boundaries for Area layers
with MODFLOW-2000. 01/10/26 Converted formats of PCG2 inputs to fixed-format under
MODFLOW-96. Fixed bug in MODPATH export. Fixed bug in
activating stream package. For MODFLOW-2000 models that use
the Stream package, it is no longer necessary to set Flow
to -1 for segments that have tributaries. Added option to
MODPATH to deal with large combined budget files. 01/09/28 Fixed bug that would sometimes result in invalid unit
numbers being assigned. Fixed bug that would generate
harmless errors in the Blocklist PIE. Added warning
message that "Manual Calculation" should be turned off
before exporting a model. Converted input for Advection
Observation package to free format. Fixed bug in export
of GHB package under MODFLOW-96. Converted formats of
solver inputs to free-format under MODFLOW-96. 01/09/04 Implemented support for YCINT-2000 and Beale-2000 01/08/31 Allowed users to get rid of "Area" layers for certain
boundary conditions. Changed expression for starting
head to make it consistent with the expression for
IBOUND. Fixed misspelled function call in export for
MOC3D. Fixed bug that sometimes prevented Argus ONE
from running a model if two models in different
directories had been opened. 01/08/22 Added support for the HYDMOD package and 3D Groundwater
Explorer. Fixed bug that could prevent export of input
files from completing if GWT was used and only some
input files were being exported. 01/08/20 Fixed bug that prevented the display of the MODFLOW-2000
mode from being saved properly. Fixed bug that caused
description to be lost. Fixed bug that caused "Weight"
variables in data sets 2 and 3 of the FHB package to be
formatted incorrectly. 01/08/16 Fixed bug that prevented specification of parameters for
the stream package for MODFLOW-2000. 01/07/27 Fixed bug that halted export of Stream package with
MODFLOW-2000 unless stream observations were used.
Added HANI to the types of parameters supported for the
Layer Property Flow package. 01/07/17 Fixed bug in import of old models that would halt the
import process incorrectly. 01/07/16 Fixed bug with name file being exported incorrectly when
a package was deactivated but the corresponding
observation package had not been deactivated. Improved
error checking when changing the type of a multiplier
array. Fixed bug with display of certain Argus ONE
parameters when related MODFLOW-2000 parameters were set
in the sensitivity package. Added support for Stream
and Stream-observations packages. Fixed bug with export of
Simple Reactions package with the MODFLOW-2000 ground-water
transport process. Added support for the Link-AMG, the
Evapotranspiration Segments, and the Drain Return packages. 01/04/30 Fixed bug in import of MODFLOW-88 models. 01/04/23 Added support for new binary file format in MODFLOW-2000
version 1.2. 01/04/18 Fixed bug introduced in version that caused
errors when options were turned off or when canceling a
change in the Project Information dialog box. 01/04/16 Fixed bugs in export of MOC observations and in setting
parameter names in post-processing. 01/04/13 Fixed bug in export of HFB package. Added button for
calculating first-order decay rate from the half-life.
MODFLOW-2000 Global file is now only produced if parameter
estimation is used. Two new mesh-related functions added
to EditContours PIE. Fixed bug in export of ISLAY1 and
ISLAY2 with the GWT process. 01/04/10 Fixed bug in Gridded Import PIE that caused parameter
names to be garbled. Fixed bug with MOC3D well observations
that sometimes caused access violations if well observations
were used. Fixed bug with MOC3D that sometimes caused
errors if only the well package was exported. Fixed bug in
handling of MODPATH under MODFLOW-2000 when steady state
and transient stress periods are both present. Fixed name
conflict between MODFLOW-2000 zone file and Zonebudget zone
file. Improved handling of system resources leading to
enhanced stability under Windows 98. Eliminated extra
"file open" dialog box when exporting MODFLOW-2000. Fixed
export of vertical hydraulic conductivity in MODFLOW-2000
Quasi3D layers. 01/03/23 Fixed bug in export of Head observations when observations
extend over multiple layers and the BCF package is used.
Fixed bug with calculation of subgrid boundaries when
viewing project information dialog box. 01/03/13 Fixed bug with exporting MODPATH input files with MODPATH
version 4.1. Fixed bug with handling errors when
observations are specified incorrectly. Fixed bug
exporting output control when the frequency of printing
or saving information was 0. Fixed bug in display of
vertical hydraulic conductivity when vertical anisotropy
was specified using parameters. Increased size of data
sets that can be imported via Post-Processing. 01/03/02 Fixed bug with importing existing MODFLOW models on
computers in which the decimal separator is not a period. 01/02/27 Fixed bug with deletion of stress periods. 01/02/16 Fixed bug with exporting WETDRY in the LPF package. 01/02/16 Fixed bug with renumbering stress period parameters after
inserting parameters. 01/02/15 When MOC3D or GWT are deactivated, the GUI now asks
whether to turn off the CTOCH option rather than leaving
it turned on. Fixed bug with parameters being turned on
incorrectly when loading files. 01/02/13 Added support for ground-water transport (GWT) process in
MODFLOW-2000. Added support for SFR package but this
option is disabled pending release of the SFR package.
Fixed bugs in export of Dual Porosity and Simple reactions
packages. Fixed problem with errors being reported
incorrectly for Area Wells. Fixed problem with wetting flag
in MODFLOW-2000. Fixed problem with reading initial heads
from a binary file in MODFLOW-2000. Fixed problem with using
non-US regional settings. Fixed bugs in exporting storage
factors for convertible layers when storage factors are
specified directly rather than calculated. Fixed bug in
importing recharge and evaporation package inputs from
existing MODFLOW models in models with multiple stress
periods. Fixed bug in importing existing MODLFOW models in
which the name file had blank lines. Fixed bug in export of
stream diversions. Updated procedure for importing wells to
support new parameters required by MODFLOW-2000. Changed
export of Advection Observation package to reflect changes
in the package in MODFLOW-2000 version 1.1. 00/10/19 Fixed bugs in export of Well, Drain, General-Head
Boundary and River packages with MODFLOW-2000. These bugs
were introduced in version 00/10/18 Fixed export of Flow and Head Boundary package with
MODFLOW-2000. 00/10/17 Fixed export of Output Control with MODFLOW-2000.
Fixed memory leaks. Updated GW_Graph to support reading
gages with new stream package. Added work-around for
access violations caused by failure of Argus ONE to
properly release PIE memory when it quits without saving.
Fixed non-editable values for Recharge, LPF, and
Evapotranspiration parameter clusters. Increased
efficiency. 00/10/06 Added two new functions to EditContoursPIE: "Import
Points from Spreadsheet" and "Import Contours from
Spreadsheet". See EditContours.hlp for details.
Fixed export of GHB under MODFLOW-2000 where a geologic
unit is divided into more than one layer. 00/10/04 Corrected problem with evaluating layers if the user
chose not to copy parameter values to the clipboard when
copying contours.
Changed MOC3D version from 3.01 to 3.5. 00/10/02 Corrected problem starting the resan program after
running MODFLOW-2000. 00/09/21 Corrected problem with FHB package under MODFLOW-2000 in
which comments were not separated from the data by at
least one space. 00/09/21 Corrected expressions of "Parameter Name" from 0 to ""
and changed the expression for "IS PARAMETER" from
'Parameter Name!=""' to
'(Parameter Name!="")&(Parameter Name!=0)'. 00/09/19 Fixed problem with stress period not being read correctly
from files saved with version 3 of the MODFLOW GUI. 00/09/11 Fixed problem with FHB fluxes being exported incorrectly.
Fixed problem with incorrectly generating an error
messages with the FHB package. 00/09/05 Changed expressions for "Parameter Name" and "IS PARAMETER"
from $N/A to "" and from 'Parameter Name!=$N/A' to
'Parameter Name!=""' to avoid problems in Argus ONE that
might cause Argus ONE to crash.
Fixed problem that could cause parameters to be locked
incorrectly. 00/09/01 Locked interpretation method for the following layers to
prevent "IS PARAMETER" from being evaluated incorrectly.
Wells Unit[i], Line Wells Unit[i], Area Wells Unit[i],
Point River Unit[i], Line River Unit[i], Area River Unit[i],
Point Drain Unit[i], Line Drain Unit[i], Area Drain Unit[i],
Point Gen Head Bound Unit[i], Line Gen Head Bound Unit[i],
Area Gen Head Bound Unit[i], Horizontal Flow Barrier Unit[i].
Fixed bug in export of hydraulic conductivity with the BCF
package under MODFLOW-2000. Improved importing of solver
information. 00/8/21 Added support for MODFLOW 2000. Added support for Lake,
Interbed storage, Reservoir, and Gage packages, Added
support for MOC3D ELLAM solver, GW_Chart supercedes
Budgeteer and Hydrograph Extractor. Added capability of
importing existing MODFLOW models. Utility PIEs added
that allow editing of data layers, importing gridded
data to data layers and evaluating expressions at arbitrary
X,Y coordinates.
Fixed bug in export of VCONT when VCONT was specified
directly. Fixed bug in export of MODPATH information.
Fixed bug in BlockList pie that would cause incorrect
conductances to be calculated for horizontal flow barriers.
Changed Budgeteer to support file names used by
Processing MODFLOW for Windows and Groundwater Vistas.
Fixed bug in Hydrograph Extractor that would cause it to
report an error if you tried to plot the head of an inactive
cell. 00/02/07 Fixed display of the "About" dialog box in Budgeteer on
computers using large fonts. Warning message is displayed
if the user does not have permission to write
LastTemplate.met to the directory where the MODFLOW GUI
is installed. Fixed bug in export of stream diversion numbers.
Corrected error in expressions for locations of drains and
rivers specified with point contours. 99/12/30 Corrected misspelling in Edit Project Info dialog box.
Corrected bug in Budgeteer that prevented column titles
from being written to a file except in the first zone
Fixed corrupted help file. 99/11/08 Fixed bug in export of river package when alternative export
template was used. Made addition of new layers faster.
Fixed bug in canceling Edit Project Info dialog box. Added
support for Age, Double Porosity and Simple Reactions
packages in MOC3D 3.0 99/10/03 Fixed bug in export template for MODPATH that would cause
it to produce incorrect input files if the parameter order
was changed. Fixed bug in JoinFiles PIE that would prevent
files from being renamed properly if a file with the new
name already existed. Changed List PIE to allow it to invert
all the members of a 3D list even if some of the members
were equal to zero. Increased speed at which new layers are
added to a project by the MODFLOW GUI. 99/09/03 Added new parameter to Grid (Prescribed Concentration Unit[i])
to improve the way in which MOC3D concentrations are exported. 99/09/02 Fixed bug that caused EVT parameters to be exported
incorrectly if the order of the parameters was changed.
Installer no longer installs ctl3d32.dll. This must be
installed manually on Windows NT 3.51. It is not required
for Windows 95 or Windows NR 4. 99/08/20 Fixed bug that caused MOC3d flow vectors to be reversed
under some circumstances. 99/08/20 Fixed bug that prevented the editing of FHB times under
some circumstances.
Modified Hydrograph Extractor to support reading MOC3D,
MT3D, and SUTRA files.
Fixed bug in expression for MODFLOW FD Grid.Initial Head Unit[i]
when the "Average Points and Open Contours" method is used.
Fixed bug in export of wells when vertical discretization is
greater than 1. 99/08/10 Fixed bug in code for inserting new stress periods.
Modified Hydrograph Extractor to support reading
large data files under Windows 95. 99/08/04 Added Point Rivers and Point Drains. Fixed bug that
prevented the "Time-varying constant concentrations"
check box from working properly in the customized version
Fixed bug that set the status bar color to the wrong
color in the customized version. Added warning about
model paths that may not be exported correctly by Argus
ONE because they contain "\n".
Fixed bug that allowed users to include blank spaces in
the root names of files. Changed name of choice for
"Method for assigning the IBOUND parameter and prescribed
heads in the initial head MODFLOW FD Grid parameter" from
"Method from MF-GUI versions 1 and 2" to "Method from MF-GUI
version 2" because those methods were different. Fixed bug
that would cause Argus ONE to crash if a MOC3D subgrid was
used on a computer in which the regional settings specified
that a character other than "." was used as the decimal
Fixed bug in customized version so that user can choose
not to export data for some MT3D packages. Eliminated locks
on the MT3D Postprocessing layers.
Table headings in the Import Wells form can now be
rearranged. To do this, click on a heading and move it
to a new position.
Minor bug fixes in customized version of MODFLOW GUI.
Updates to online help.
HydrographExtractor modified to read MT3D Observations file.
Added support for importing concentrations for wells
with MT3D in customized version of MODFLOW GUI. 99/06/28 Minor additions to help file. Progressbar PIE now updates the
elapsed and estimated time remaining once each second. The method
used to advance the progress bar has been changed. In the contents
of the help system, the titles of some items have been abbreviated
as a way of working around a bug in the Windows 98 help system.
With the longer titles, Winhelp would crash under Windows 98 but
not Windows 95 or Windows NT 4.0. New capabilities added to
Hydrograph Extractor: (1) reading and writing a file of cell
locations and (2) User can choose activate or deactivate individual
series in the chart. MODFLOW_JoinFiles PIE modified to avoid errors
when attempting to rename files on network drives. Fixed bug
in MODFLOW_CheckVersion PIE function. 99/05/28 Modifications to support use of a comma as a decimal separator. 99/05/ 25 Contour2Data export template corrected. New function added to
Edit Contours PIE, Data2Contour, that converts data points
to point contours. Warning message added to GUI when the user
activates MODPATH or ZONEBDGT telling them that they may need
to rerun MODFLOW. Added function to Join Files PIE to facilitate
correct naming of files when the files will be read by DOS.
Added protection for ZONEBDGT stress periods and time steps
that are not entered correctly. Fixed bug in checking that
ZONEBDGT time steps are correct. 99/05/20 Changes made to facilitate customization but no change in
functionality. 99/05/19 Additional information added to online help system. Fixed bug in
renaming *.s[i] files. Fixed bug that caused program to crash
when running on programs in which registration information
for Argus 5 is not installed. 99/05/14 Fixed bug that caused porosity grid
parameter not be created correctly in some circumstances. Fixed
bug due to models not recognizing file names with extensions
longer than 3 characters. Extensions of Zonebudget zone array
files and specific yield files changed to .a and .y respectively.
PIE functions in progress-bar and join-files PIES were hidden
from the user. 99/05/13 Fixed bug in routine to recognize files saved by previous
version of PIE. . Activated code to ensure
that options are set properly during export.

3.0 99/04/28 Addition of Help system, STR1, HFB1, FHB1,
MODPATH, and ZONEBDGT; numerous less significant changes
as detailed in the documentation.

2.0 98/07/14 Addition of MOC3D solute-transport model, several
cosmetic changes

1.41 97/08/12 Error corrected that occurred when considering a confined
aquifer and a transient simulation.

1.4 97/07/23 For geologic units designated as "confined" and for
transient simulations, the value exported for
storativity has been corrected to the specific storage
multiplied by the thickness of the model layer.

The Evapotranspiration package correctly exports
information for time-variable and steady stresses.

Specific data files can be exported. In
previous versions, all data files used by MODFLOW-96
were exported by default.

To expedite the export of data associated with the
General Head Boundary, River, Drain and Well
packages, cells in the three-dimensional
finite-difference grid are checked to see whether
they have stresses specified in them or not.

Selected geospatial information is checked upon
exporting. Errors or warnings detected during the
export are written to a file named Rootname.ERR, where
Rootname is the file name specified in the Output Files
dialog box.

1.3 97/06/02 Error corrected in export of vertical
conductance in the .BCF file for geologic units
designated as "simulated" and having a zero value
for the vertical hydraulic conductivity.

Postprocessing of three-dimensional surfaces is
handled properly so that the application does not
crash inadvertently.

1.2 97/05/13 Error corrected in handling of geologic units
designated as "unconfined" (LAYCON=1) and
simulated with more than one model layer.

Error corrected in export of the wetting
threshold for geologic units that are designated
as "unconfined" (LAYCON=1) and "convertible"

1.1 97/04/18 Error corrected in handling of geologic units
designated as "convertible" (LAYCON=3).

In the Output Files dialog box, the rootname for
files is saved such that it is retained when the
project information is reloaded.
Extraneous lines following the hydraulic
conductivity in the BCF data set have been

Real-value input fields in the tab dialog boxes
accept decimal input on all operating systems.

The units in the layer menu for Kx and Kz have
been corrected to L/T.

Default values for the following parameters have
been changed as follows:

In the Misc. Controls dialog box:
ISTRT: from 0 to 1

In the PCG Solver dialog box:
PCG_HCLOSE: from 0.1 to 0.01
PCG_RCLOSE: from 0.1 to 1000.
PCG_MUTPCG: from 0 to 1
PCG_IPRPCG: from 2 to 1

1.0 97/03/14 Initial release.

DATA REQUIREMENTS In order to use MODFLOW-96, initial conditions, hydraulic properties, and stresses must be specified for every model cell in the finite-difference grid. OUTPUT OPTIONS Output produced by the MODFLOW-GUI preprocessor is a complete set of files for use with MODFLOW-96 and MOC3D. SYSTEM REQUIREMENTS MODFLOW-GUI is compiled for use with Argus ONE version 4.1, revision t or later, on personal computers running Microsoft Windows 9x or NT. DOCUMENTATION Shapiro, A.M., Margolin, J., Dolev, S., and Ben-Israel, Y., 1997, A graphical-user interface for the U.S. Geological Survey modular three-dimensional finite-difference ground-water flow model (MODFLOW-96) using Argus Numerical Environments: U.S. Geological Survey Open-File Report 97-121, 50 p. Hornberger, G.Z., and Konikow, L.F., 1998, Addition of MOC3D solute- transport capability to the U.S. Geological Survey MODFLOW-96 graphical-user interface using Argus Open Numerical Environments: U.S. Geological Survey Open-File Report 98-188, 30 p. Winston, R.B., 1999. Upgrade to MODFLOW-GUI: Addition of MODPATH, ZONEBDGT and Additional MODFLOW Packages: U.S. Geological Survey Open-File Report 99-184, 63 p. Winston, R.B., 2000, Graphical User Interface for MODFLOW, Version 4: U.S. Geological Survey Open-File Report 00-315, 27 p. RELATED DOCUMENTATION Harbaugh, A.W., Banta, E.R., Hill, M.C., and McDonald, M.G., 2000, MODFLOW-2000, the U.S. Geological Survey modular ground-water model -- User guide to modularization concepts and the Ground-Water Flow Process: U.S. Geological Survey Open-File Report 00-92, 121 p. Hill, M.C., Banta, E.R., Harbaugh, A.W., and Anderman, E.R., 2000, MODFLOW-2000, the U.S. Geological Survey modular ground-water model -- User guide to the Observation, Sensitivity, and Parameter- Estimation Processes and three post-processing programs: U.S. Geological Survey Open-File Report 00-184, 210 p. Harbaugh, A.W., and McDonald, M.G., 1996, User's documentation for MODFLOW-96, an update to the U.S. Geological Survey modular finite-difference ground-water flow model: U.S. Geological Survey Open-File Report 96-485, 56 p. McDonald, M.G., and Harbaugh, A.W., 1988, A modular three- dimensional finite-difference ground-water flow model: U.S. Geological Survey Techniques of Water-Resources Investigations, book 6, chap. A1, 586 p. Konikow, L.F., Goode, D.J., and Hornberger, G.Z., 1996, A three- dimensional method-of-characteristics solute-transport model (MOC3D): U.S. Geological Survey Water-Resources Investigations Report 96-4267, 87 p. Leake, S.A., and Lilly, M.R., 1997, Documentation of a computer program (FHB1) for assignment of transient specified-flow and specified-head boundaries in applications of the modular finite-difference ground-water flow model (MODFLOW): U.S. Geological Survey Open-File Report 97-571, 50 p. Hsieh, P.A. and Freckleton, J.R., 1993, Documentation of a computer program to simulate horizontal-flow barriers using the U.S. Geological Survey modular three-dimensional finite-difference ground-water flow model: U.S. Geological Survey Open-File Report 92-477, 32 p. Prudic, D.E., 1989, Documentation of a computer program to simulate stream-aquifer relations using a modular, finite-difference, ground-water flow model: U.S. Geological Survey Open-File Report 88-729, 113 p. CONTACTS Operation and distribution: U.S. Geological Survey Hydrologic Analysis Software Support Program 437 National Center Reston, VA 20192 h2osoft@usgs.gov Official versions of U.S. Geological Survey water-resources analysis software are available for electronic retrieval via the World Wide Web (WWW) at: http://water.usgs.gov/software/ and via anonymous File Transfer Protocol (FTP) from: water.usgs.gov (path: /pub/software). The WWW page and anonymous FTP directory from which the MODFLOW-GUI software can be retrieved are, respectively: http://water.usgs.gov/software/modflow-gui.html --and-- /pub/software/ground_water/modflow-gui If you would like to obtain the price of and (or) order paper copies of USGS reports, contact the USGS Branch of Information Services at: USGS Information Services Box 25286 Denver Federal Center Denver, CO 80225 To inquire about Open-File Reports or Water-Resources Investigations Reports: Tel: 303-202-4200; Fax 303-202-4695 To inquire about other USGS reports: Tel: 303-202-4700; Fax 303-202-4693 SEE ALSO

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Last Iteration: November 29, 2013