Aquaveo & Water Resources Engineering News

MNW2 - Multinode Well 2 Package

GMS version 8.3 has added support for the MNW2 package in MODFLOW. This package is an update to the MNW1 package. In addition to supporting the capabilities of the MNW1 package, the MNW2 package can also calculate additional head changes due to partial penetration affects, flow into a borehole through a seepage face, changes in well discharge related to changes in lift for a given pump, intraborehole flows with a pump intake located at any specified depth in the well, and improved capability to simulate nonvertical wells.

Take a look at the GMS learning center here for new tutorials with the MNW2 package.

GMS supports manually creating/editing MNW2 boundary conditions directly on the MODFLOW grid.

In addition, the conceptual modeling tools have been updated to support the MNW2 package.


GMS continues to add support for MODFLOW packages. Look for more packages in the near future. Happy modeling!

June 2012 Sprint Highlights

Some of the more interesting accomplishments from the June 2012 sprint:
  • Fixed over 10 bugs
  • Switched all model code to use the newer version of Visual Fortran
  • Taught a GMS training course in France
  • Good progress on the MODFLOW SUB package interface
  • Updated MODFLOW-NWT with the latest from the USGS
  • Overhauled the MODFLOW menu to make it more usable
  • Implemented more raster features including a raster catalog and virtual earth dialog buttons
  • Added text in the MODFLOW Global Options dialog to show what MODFLOW executable will be used
  • Added support for multiple CAD files
  • Created a CAD properties dialog
  • Overhauled how z values relate to the active data set for TINs, 2D meshes and 2D scatter points to make it simpler and easier
  • Started displaying the current project and the latitude and longitude at the bottom of the graphics window

May 2012 Sprint Highlights

Some of the more interesting accomplishments from the May 2012 sprint:
  • Fixed over 19 bugs
  • Overhauled the MODFLOW ccf file reader to be more generic
  • Much progress on the MODFLOW SUB package
  • Updated MODFLOW 2005 executable with the latest changes from USGS
  • Mostly finished phase 1 of PEST Null Space Monte Carlo support
  • Began adapting MODFLOW LGR to GMS format
  • Finished several raster features including interpolation and conversion to/from other object types
  • Added more "Open containing folder" commands where they were needed
  • Made it so we just link to CAD files instead of saving them with the project
  • Added duplication of MODFLOW array data in the Project Explorer
  • Removed the interface for flow observations with the SFR package since MODFLOW doesn't support this
  • Added commands to Expand / Collapse most items in the Project Explorer
  • Split the MODFLOW conceptual model tutorial into two separate tutorials
  • Finished the MODFLOW MNW2 package tutorial for non-vertical wells and pump capacity
  • Added more bitmaps in the menus and made the old ones look better

GMS Training, Nancy, France - Recap

From June 12-15, 2012, members of the GMS development team and Dr. Norman Jones taught a GMS training course in Nancy, France at the Institut National Polytechique de Lorraine.

Many thanks to Dr. Fabrice Golfier for helping to organize the class. Individuals from Europe and the Middle East were able to come together and learn about the most advanced groundwater modeling software available, GMS. Once again the course attendees commented on the many powerful features available in GMS and how they could use the software in their work. Thanks to all those who attended.

Dr. Norm Jones teaching a lecture during the course

Velocity vectors

Beginning with version 8.2, GMS can now generate velocity vectors using information from the MODFLOW cell-to-cell flow (ccf) file. Several pieces of information are required to compute groundwater flow velocity from a MODFLOW model. First, the amount of flow in the I, J, and K directions for a given cell is read from the CCF file. If a particular cell contains a boundary condition that is withdrawing water (such as a well) then the flow in the I, J, and K directions is decreased based on the amount of flow leaving the cell through the boundary condition. Next, the saturated area is calculated in the I, J, and K directions. For the I and J directions it is necessary to use the top and bottom elevations that are specified in MODFLOW's discretization package. If the particular cell is part of an unconfined aquifer then it is also necessary to get the computed head for the cell as the computed head is most likely below the top elevation of the cell. The final piece of information necessary for the calculation is porosity. Although porosity is not part of the MODFLOW inputs, using GMS you can specify porosity on a per cell basis. Once the flows, areas, and porosity are assembled the groundwater flow velocity is computed using the following equations:

Velocity.I = Flow.I / (SaturatedArea.I * porosity)
Velocity.J = Flow.J / (SaturatedArea.J * porosity)
Veloctiy.K = Flow.K / (Area.K * porosity)

To create a velocity vector data set from a MODFLOW CCF file in GMS you simply right click on the CCF data in the GMS Project Explorer and select the CCF -> Velocity Vectors command.
Conversion from CCF to Velocity Vectors

Once you have a vector data set you can adjust the display of the vectors by going to the Display Options dialog for the 3D grid and turning on the Vectors check box. If you select the Options button next to the Vectors check box you have further control over the display of the vectors.
Velocity Vector Plot in GMS

April 2012 Sprint Highlights

Some of the more interesting accomplishments from the April 2012 sprint:
  • Fixed over 21 bugs
  • Held a training course in Orem, Utah
  • Completed MODFLOW SUB package to about 40%
  • Added support for all file formats supported by Global Mapper
  • Added dynamic online imagery via Global Mapper
  • Identified the changes needed to support the SFR2 inputs used with UZF
  • Switched next version number form 8.4 to 9.0
  • Completed most of the work needed for PEST null space Monte Carlo support with RANDPAR
  • Added the ISTCB2 option in the STR package
  • Added a model checker for the SFR package
  • Added an option to only save the groundwater data in the UZF package
  • Added wells in the MT3D TOB package so it tracks (and we can plot) mass vs. time
  • Added all array-based parameter types to the set of those that can use pilot points with PEST
  • Made the gage folder in the MODFLOW solution start out collapsed by default
  • Added the GMS version number to the main window title
  • Renamed "Convergence Options" to "PEST ASP Package" to help identify what it is
  • Switched to new round logos
  • Made improvements to the pilot points, transient, and gage tutorials
  • Continued improvements to the wiki

March 2012 Sprint Highlights

Some of the more interesting accomplishments from the March 2012 sprint:
  • Posted GMS 8.3 beta
  • Added two new videos to our YouTube channel on regional to local model conversion and contour options
  • Fixed over 10 bugs
  • Added a machine to help with nightly testing
  • Added a few new testimonials
  • Started on the PHT3D interface design
  • Moved SFR outputs related to ISTCB2 to a separate CCF file so they don't get included in the flow budget.
  • Fixed the Check For Updates command to warn if the maintenance has expired to avoid downloading an update that can't be used.
  • PEST Null space Monte Carlo progress
  • Came up with a fix for broken images when converting the wiki to OpenOffice
  • Designed Global Mapper dynamic images
  • Finished adding support for the MODFLOW Gage package
  • Added a new Measure tool
  • Added new Locate Selections and Zoom To Selections commands
  • Simplified the MT3D Sink & Source Mixing Package dialog
  • Enhanced the model checker and added tests for MT3D SSM, RCT and ADV packages.
  • Held a training course in Mexico City
  • Made several improvements to the Model Calibration tutorial
  • Started splitting the Conceptual Model Approach tutorial into two
  • Made exported shapefiles include a projection (.prj) file whenever the projection is not local

Training Mexico City, Mexico

A GMS training course was held from March 5-8 in Mexico City, Mexico. Alan Lemon of the GMS development team and Dr. Willis Weight of Carroll College, Montana taught the course.

The course was well attended. More than 20 people attended the course. There was a wide variety in the amount of experience with groundwater modeling. Some attendees had been building models for years, while others were relatively new to groundwater modeling. Also, the attendees came from many different backgrounds including: professors at universities, consultants, and students. Based on the comments submitted after the course, the attendees felt like they all learned something valuable that they could use in their work. Many attendees commented on how much easier it was to build models using GMS than other MODFLOW preprocessors. They appreciated using the conceptual model approach and having their data independent of a MODFLOW grid.

Thanks to Jorge Chipres and Catalina Morato for their efforts in organizing the course.

Exporting 3D Grids to Shapefiles

In GMS 8.2 we added the ability to export a 3D grid to a shapefile. All layers of the grid are exported, along with the active data set and the grid cell activity (IBOUND) and data set activity (dry cells) if they exist. Here is the list of the attributes that get exported:
  • cell ID
  • cell I
  • cell J
  • cell K
  • grid cell activity
  • active scalar data set values
  • active data set activity (if it exists)
A simple definition query using the grid cell activity and K fields can be created in ArcMap to see one layer of the grid at a time. For example, the following figure shows the head solution on the third layer of the grid from the lake package tutorial as a shapefile in ArcMap.


With the release this week of GMS 8.2, GMS includes support for MODFLOW-NWT including the UPW package and NWT solver. Compiled versions of the MODFLOW-NWT executable are included with the GMS installer, including versions for 64 bit and double precision. A new tutorial covering the NWT interface has been added and is included in the tutorial installer and is also available via the learning center.