GMS

Using Layer Range Options in GMS

By aquaveo on October 5, 2022

The conceptual model approach in GMS is a very useful way to assign specific attributes to a MODFLOW model without having to manually input them cell by cell. One particularly helpful tool available in a GMS coverage is the "Layer Range" option.

Example of the Coverage Setup for Layer Ranges

Layer range can be used in addition to other coverage choices—such as streams, wells, rivers, head boundary, etc.—allowing you to be as precise as you need to be when applying your model attributes.

In the past, we have mentioned this tool in a blog post about assigning Ugrid attributes to specific layers, but that is only one of many helpful ways to use it. Here, we will go over each of the options available with the Layer Range, and exactly how they work.

First, turn on this option by selecting "Layer Range" in the sources/sinks column of the coverage setup dialog. At the bottom of this dialog, make sure that the default layer range for the coverage covers all the parts of your grid that you wish to use.

Second, apply feature objects to your coverage. In our example, we have created a Time-Variant Specified Head arc.

Example of the Layer Range Assignment in GMS

Once your feature objects are in place, you can assign values to them in the attribute table. This is where the Layer Range settings will come into play.

Use Layer Range: This option applies your feature objects to a specific range of layers. That range is selected in the attribute table under "From Layer" and "To Layer". A feature point assigned a layer range of 2–6 will be applied to every cell in that vertical column from layer 2 to layer 6.
Similarly, a polygon or arc will apply its attributes to the whole assigned layer range for every vertical column that it intersects.
Auto-Assign BC to One Cell: Any time you want only one cell per column, you can choose "Auto-Assign BC to One Cell". This setting is especially useful when mapping an object type that can't or shouldn't be applied to more than one vertical cell at a time. Stream arcs are one example.
Auto-assigning to one cell will use the elevation inputs from your feature object to choose the most applicable cell in that vertical column to receive the assigned attributes.
Auto-Assign BC Including Lower Cells: This setting allows the coverage to automatically calculate which initial layer the object is applicable to, similar to the "One Cell" option. It then applies the object to that cell, and to everything below it within the range of the coverage.
Including the lower cells is very useful when you do want more than one vertical cell to be assigned, but need different layer ranges for different parts of the same feature object.

Once you have selected the Layer Range option that best suits your model, you can map the coverage to your simulation. The results can be viewed in the MODFLOW | Optional Packages dialogs, as well as the Sources/Sinks table in the right-click menu for the grid cells.

The Layer Range tool is a great way to get your model attributes as specific as you need them to be without any laborious manual editing. Try it out in your GMS model today.

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GMS

New Features in GMS 10.7 Beta

By aquaveo on September 14, 2022

We are pleased to announce that GMS 10.7 has been released in beta. In order to improve your groundwater modeling projects, we’ve included many new features into GMS 10.7. Here are a few of the new features we are excited about.

Animation Tools Allow Exporting in MP4 File Formats

GMS 10.7 has been improved to allow you to save your animation files in the MP4 format. This will enable you to open animation files outside GMS and view the animation created before returning to GMS. An MP4 file is a common animation file that allows you to open the animation in a number of different player applications.

Introduction of the New Toolbox Features

GMS has added a new Toolbox feature. This Toolbox contains many different tools for completing common calculations and functions in GMS. For example, the new Toolbox contains a tool for merging datasets and another tool for converting geometries to an unstructured grid. We have provided dozens of tools in the Toolbox to work with a wide range of data, so we recommend looking through the available tools to see what would be of most use for your projects.

Many of the tools in the Toolbox can be used instead of using the Data Calculator. This shortcuts some of the processes to help you build your groundwater model faster. Additional tools will be added in future versions of GMS. If you have a common process that you would like to see added as a new tool in the Toolbox, please let us know.

Updated MDT Package for MODFLOW 6

In MODFLOW 6 has updated the MDT package. The MDT package allows for matrix delineation transport as well as shifting matrix delineation start time. Improvements have been made to how this package works with MODFLOW 6 in GMS.

These are just a few of the features that are a part of GMS 10.7 beta. Try out these features and more by downloading GMS 10.7 Beta today!

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GMS

Using Map from Coverage in GMS

By aquaveo on August 24, 2022

If you are using MODFLOW 6 in GMS, you may notice that it uses a different workflow than other versions of MODFLOW in GMS. These changes were made to improve flexibility and performance for groundwater modeling in GMS. One difference is the process of mapping data from the conceptual model to the MODFLOW simulation. In all versions of MODFLOW in GMS, mapping involves taking data input in the conceptual model and "mapping" that data to the grid or mesh being used by the MODFLOW simulation. With every other version of MODFLOW, this is accomplished using the Map to MODFLOW command. However, in MODFLOW 6, mapping is accomplished using the Map from Coverage command.

Now, why this change? It mostly has to do with differences in how GMS handles these different kinds of MODFLOW. A GMS project can only hold one older MODFLOW simulation, but GMS was improved to allow multiple MODFLOW 6 simulations in a project. For handling multiple models and simulations, the Map to MODFLOW command is insufficient. There might be multiple simulations in your project, and you might not want the coverage or conceptual model you are pulling data from to map to all of these MODFLOW 6 simulations.

So how does the new command work? For a MODFLOW 6 package in GMS, do the following:

Right-click on the simulation package and select the Map from Coverage command.
Select a coverage for GMS to map over the package.

Example of the Map from Coverage coverage

GMS will then map the data from the coverage into the MODFLOW 6 package. It's important to note that only some of the MODFLOW 6 packages can be mapped from coverages. This means some packages must be manually set up in their package dialog. This new workflow can have some important effects on how you build your MODFLOW 6 simulation. In MODFLOW 6 it’s especially important that you map over the correct coverage. Since the data isn’t generically mapped over to MODFLOW, it’s especially necessary to know which coverage will be used to define each MODFLOW 6 package.

Try out the Map from Coverage process for MODFLOW 6 in GMS today!

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GMS

Risk Analysis for Well Groups

By aquaveo on August 3, 2022

In your groundwater model, do you need a way to capture multiple wells for risk analysis? For example, your project might have multiple pumping wells and you would like to see the probabilistic composite capture zone for all wells in the wellfield. GMS provides a way to access the Risk Analysis dialog for refining stochastic modeling results.

Example of the Risk Analysis Wizard in GMS

First open your project in GMS, making sure to select the Plan View and 3D grid module, it will be more difficult to select wells otherwise.
Using the Select Cells tool, drag a box around the entire grid to select all cells in the grid.
Open the 3D Grid Cell Properties dialog and change the value for the MODPATH zone code to a number of your choice.
Select the coverage of the well to make it active. Using the Select Points/Nodes tool, drag a box around the entire project to select all wells in the coverage.
Select Intersecting Objects to open the Select Objects of Type dialog.
Select 3D grid cells from the list and close the dialog. This will select all 3D grid cells that have a well in them.
Open the 3D Grid Cell Properties dialog.
Change the value for the MODPATH zone code to a different number than the one that was used before, close the dialog and save changes. From here, the probabilistic capture zone analysis should be able to run with the well groups setting turned on.

Please note that particles need to leave their original zone to be mapped on the risk analysis results. That is why nothing will show up when all cells were assigned to the same zone. The recommended solution is to change the zone code of just the cells with a well so that as many particles as possible can leave the assigned area.

GMS allows you to be as general or specific as you need when selecting wells for risk analysis. Try out using risk analysis for well groups using GMS today!

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GMS