Aquaveo & Water Resources Engineering News

May 2011 Sprint Highlights

Some of the more interesting accomplishments from the May 2011 sprint:

  • Added three new GMS videos on the YouTube channel.
  • Fixed 24 bugs
  • Created an installer for GMS 8.1 for 32 and 64 bit
  • Created 64 bit versions of MODFLOW
  • Got 64 bit tests of MODFLOW running
  • Added a preference for 64 bit MODFLOW
  • Made good progress on restoring ability to contour and block fill at the same time
  • Finished fixing the annotation bugs to be included in 8.1
  • Created a local help page, similar to the online learning center, which will direct users to the tutorials installed locally
  • Created a table of contents for the wiki and got PDF generation of the wiki working. A locally installed PDF version of the wiki will be available with GMS 8.2.
  • Added code to MT3D model checker to look for missing species in the conceptual model
  • Almost finished basic raster implementation (raster objects coming in GMS 8.2)
  • Wrote a design for MODFLOW-NWT
  • Changed some MODFLOW dialogs to conform to the standard for variable names
  • Made lighting dialog display changes instantly in graphics window

GMS Resources for Educators

We recently created the GMS Resources for Educators page at There you can find sample lectures, in-class exercises, and homework assignments for a one semester, college level course in groundwater modeling. The course teaches groundwater modeling principles with an emphasis on MODFLOW and MODPATH. GMS is used as one of the software tools in the course and a lot of time is spent building real models on the computer. From the course description, "This course is application oriented. We cover the fundamental equations and the modeling theory but the emphasis is on teaching you how to solve real world problems. At the end of the semester, you should feel confident in your ability to develop and calibrate a complex 3D groundwater model."

Dr. Norman L. Jones has taught this class for years at Brigham Young University as CE 547 - Groundwater Modeling. He continually updates and improves the material. To obtain the entire curriculum with a syllabus, tests, and answers to the homework assignments and the tests, email Dr. Jones

At the end of the course students complete a case study of the Woburn site described in the book A Civil Action. If you are familiar with the book or the case, you might be interested in the excellent Woburn Hydrogeology Data page maintained by Dr. Jones which includes all sorts of raw data for use in building a groundwater model, as well as photos of the area and even photos of many of the key players in the book. The case study is designed to be done with the students divided up into small teams - some teams working for the prosecution, and some for the defense.

MODFLOW and More 2011

Members of the GMS team recently attended the MODFLOW and MORE 2011 conference in Golden, Colorado. The conference was great. There were many presentations related to MODFLOW modeling and groundwater in general. One interesting development was the announcement of MODFLOW USG (Unstructured Grid). This version of MODFLOW is not yet released but it looks quite different from current versions of MODFLOW.

It was good to meet current GMS users and get feedback on improvements that can be made to GMS. Thanks to all those that came by our booth.

Contouring and block fill improvements

In GMS 8.0, the contour options were updated and improved. Most of the changes were behind the scenes in code that results in faster contouring which uses less memory and is more accurate. But the interface changed too. The old and new dialogs are shown below. The new dialog is cleaner and easier on the eyes. It also includes a new option - Block fill - for the Contour method. This option only applies to cell-centered grids and results in cells filled with a single color based on the value at the cell center. Block fill was previously only available for 3D grids as a separate display option and limited range and color ramp options. Now block fill is available for 2D and 3D grids and, because it's part of the Contour Options, the full suite of range and color ramp options are available.

Unfortunately by merging the block fill option in with the Contour Options we lost the ability to do both at the same time - that is block fill one data set and contour another data set. But the soon to be released GMS 8.1 restores the ability to do both at the same time.

Old Contour Options dialog.

New Contour Options dialog.

April 2011 Sprint Highlights

Some of the more interesting accomplishments from the April 2011 sprint:
  • Fixed 22 bugs.
  • Created 64 bit versions of MODFLOW.
  • Taught the GMS training course in Dresden, Germany.
  • Updated the tutorial docs and files on the wiki for GMS 8.0.
  • Fixed some issues with the IUZBND array in the UZF package.
  • Documented MODFLOW world files on the wiki.
  • Simplified code behind Contour Options and Raster Options dialogs.
  • Added tests for the Set Arc Directions From Stream Data feature.
  • Researched converting the wiki to a pdf or chm file.
  • Fixed some coding problems that were resulting in compiler warning.
  • Changed the Visual Studio project for 64 bit GMS to follow pattern of 32 bit property sheet.
  • Added to the suite of 64 bit test.

GMS Learning Center and YouTube channel

In order to help make it easier to learn how to use GMS, or to just see what GMS can do, we recently launched the GMS Learning Center at  All the GMS videos we've created so far are available there. These are YouTube videos so you can also find them all on our Aquaveo channel on YouTube. Look for the GMS playlist. These videos are all recorded in high-def so they're best watched full screen at 720p. We add a few new videos each month. Various folks around the office have been recruited for the voice recordings and none of them are professional voice actors but we think they've done a pretty good job.

Also at the GMS Learning Center are all the standard tutorials which ship with GMS. The tutorials can be freely downloaded and completed offline. Finally there are links to the wiki, the user forums, the training courses, and a new Resources for Educators page that will probably warrant it's own blog post in the near future.

Better MODFLOW observation plots

GMS has included observation tools for a long time. These work with any numerical model and let you compare field observed data with model computed output. With transient data, the time of the observations doesn't necessarily match the model output times. In this case GMS would do a temporal interpolation to come up with a model calculated value.

When MODFLOW 2000 came out it included built in observations calculated when you ran MODFLOW. Now if the observation time didn't match the output time it didn't matter because MODFLOW would be sure to calculate an additional output at the observation time.

The residual errors calculated by MODFLOW have been available in GMS since shortly after MODFLOW started computing them but the GMS observation plots still behaved the old way, by doing a temporal interpolation. Until now. We just replaced the old way with the new and revamped several observation plots. The following images illustrate the difference.

Old and busted. Notice the interpolation times of the upper and lower range don't always match the observation times.
New hotness. Upper and lower bands replaced with fixed point-in-time box symbols. The color makes it easier to interpret.


GMS 8 has an interface to the USGS SEAWAT model. SEAWAT is a combination of MODFLOW and MT3D that allows for the simulation of density dependent flow and transport. I have included an animation of one of the sample problems from the SEAWAT documentation. We also have created a tutorial that shows how to use the SEAWAT interface within GMS.

GMS Community Edition

Starting at GMS 8.0 there is a free version of GMS called "GMS Community Edition". This version includes the MODFLOW and 3D Grid components and thus allows grid-based creation and editing of MODFLOW simulations. Existing simulations can be imported and edited as normal. There are size limits in this free version: grids can be no bigger than 5,000 cells and MODFLOW is limited to 3 stress periods. You can still import models bigger than this but then printing and saving are disabled. Otherwise, printing and saving work as normal. Also, once a model exceeds the limits a watermark will appear in the graphics window.

We hope this free version will allow more users to easily begin discovering GMS.

March 2011 Sprint Highlights

Some of the more interesting accomplishments from the March 2011 sprint:
  • Released GMS 8.0 with lots of new features including a free Community Edition, support for MODFLOW 2005 and SEAWAT, faster and better looking graphics, improved contouring, ArcGIS map server layers, and much more.
  • Updated the GMS web pages at The graphics are better, the content and layout is much easier on the eyes, there's a new learning center with videos and tutorials, and a new editions and pricing page, and a new "Why MODFLOW with GMS?" page.
  • Posted a new video on our YouTube channel showing the MODFLOW stream package and streams in a conceptual model.
  • Fixed 33 bugs
  • Found and fixed some memory leaks
  • Finished the new lighting options that will be included in version 8.1
  • Made good progress on implementing the new Rasters that will be available in 8.2 and will handle DEM data much better.
  • Added a bunch of pages to the wiki about the SEAWAT interface.
  • Made good progress on improving the annotations that are new in 8.0 and will work much better in 8.1
  • Added more automated testing of the 64 bit version of GMS that will be available with 8.1