UNIT 10 -- MODFLOW GUIs:
Our modern world includes Graphical User
Interfaces or (GUIs) to facilitate data input and output to ground-water models.
It is essential that you can create, read, and edit
the text input and output files from a computer code, but it is also essential
that you be able to use GUIs. Without GUIs you would be so slow in your modeling
work that your company would not be competitive.
Of course, these tools will help you with your semester
project, but try to think in terms of the global issues related to the GUIs
so that you will be better able to cope with new GUIs
that we do not address in class.
We will use two MODFLOW GUIs in this class. It
is important to note their different global approach to pre-processing the
data.
First we will use Ground Water Vistas (GWV) which
was developed by Jim Rumbaugh of Environmental Simulations, Inc.
This program allows you to design a grid, specify the properties through a
variety of tools, execute MODFLOW and a number of associated models as well
as view the results in a variety of formats, undertake trial-and-error calibration
by viewing various output items and use the universal calibration codes PEST
and UCODE in a limited manner. Other GUIs that have
similar features to GWV are Visual MODFLOW which was developed by Waterloo
Hydrogeologic Software, PMWIN developed by Wen-Hsing Chiang of the University
of the Free State in South Africa, and MODIME developed by S.S. Papadopulos
& Associates.
Each GUI has its own way of specifying items that one
must learn to use them, but all of these GUIs perform the same basic functions.
All of them can import standard MODFLOW files created as described in the original
USGS manual.
The second GUI that you could use is the Ground Water
Modeling System (GMS) which was developed by Norm Jones of Brigham Young University.
This program allows the same activities as indicated
above for GWV with some additional features. The reason that I also include
GMS is that it has additional features that the other codes do not have. GMS
includes more codes, being not only a GUI for MODFLOW and its associated codes,
but also for a variety of other codes. However, the
key difference in GMS is that the user can develop a conceptual model independent
of the model grid. The conceptual model can be built
as an overlay on maps of the area and is defined in terms of GIS objects. The
user can quickly change the grid and all the details of the conceptual model
are transferred to the new grid. For example, I may
have a grid cell that overlays the intersection of three recharge zones and
includes a river reach. GMS will translate this information to the model grid
as one recharge rate for the cell that is the sum of the proportion of each
contributing area times its recharge rate and it will take the length of the
river reach and multiply by the conductance that was associated with the arc
representing the river. In the other GUIs, the user
would either have to force the grid cells to coincide with the recharge boundaries
or would have to manual calculate the net recharge. The user would also manually
calculate the conductance of the river for that cell. Later
if the user defines a finer, or coarser, grid, GMS automatically recalculates
the recharge for each cell based on the new proportional areas and calculates
a new conductance based on the length of the river over lying the new cell.
When using another GUI, the user would have to manually recalculate these values.
If you
do not have the Ground Water Modeling System (GMS) on your computer, then please
download it now from Ground Water Modeling System
Download and install it on your computer.
Then begin the registration process by sending the security
string to me epoeter@mines.edu.
Go to File>Register and e-mail the security string to
me. I will get a password and e-mail it back to you. Then
you return to File>Register, enter the password, depress Register Password,
and select Done.
* The OBJECTIVE of UNIT 10 is for you to:
* BE ABLE TO USE GUIs TO PRE and POST-PROCESS MODFLOW INPUT AND OUTPUT
* BE ABLE TO ACCESS AND MANIPULATE THE FILES THAT THE GUI PRODUCES
* UNDERSTAND THE FUNDAMENTAL DIFFERENCE BETWEEN A GUI THAT ALLOWS YOU TO PROCESS THE FILES AND ONE THAT BUILDS FILES FROM A CONCEPTUAL MODEL
* APPLY KNOWLEDGE GAINED IN THIS STUDY TO CONDUCT A PROJECT
DISCUSSION
Graphical User Interfaces (GUI's) facilitate data input and output to ground-water models.
This discussion of GUIs provides a limited illustration of their capabilities and use.EXERCISES
Read the GV Concepts Chapter in the GroundWater Vistas Manual.Look through the GMS reference manual (refman30.pdf) and tutorial (tutor30.pdf) so you will know where to find help on specific items when you need it.
COMMUNICATION
Please bring up any questions you may have about GUIs. epoeter@mines.edu