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iMOD User Manual version 5.2 (html)


11.17Tutorial 16: iMOD-WQ MT3D

This tutorial gives a brief introduction to the usage of MT3D in iMOD-WQ together with the 4D viewer. The technique of water quality modelling is extensively described in the MT3DMS manual (see [Zheng and Wang(1999)]).


Outline

This is what you will do:


Required Data

For this tutorial you need the following iMOD Data Files/folders in {tutorialfolder} \TUT_iMOD-WQ_MT3D:

Note: If you are a left-handed person and you converted your mouse button settings, ’left mouse button’ should be ’right mouse button’ and vice versa in these tutorials.


Getting Started

In this Tutorial we model a Benzene plume originating at a railway station. First we load a topography map for orientation.

Let’s open the model configuration in the iMOD Project Manager containing all the model input.

In the TreeView all possible Topics are listed, both for iMODFLOW and iMOD-WQ. From iMOD version 5.0 it is possible to thin-out the items in the Treeview in order to gain insight of the active items.

The items that are currently filled in are checked (Active). If we need more items, we can easily activate the appropriate package from the list. The Treeview will be updates once we select the tab with the treeview again.

Let ’s now take a look at the Species in the model.

pictures/Ch-imod-tutorials/mt3d-define-species.png

Figure 11.208: Window to add, rename and remove Species.

Now we are interested in the location of the Benzene contamination. Therefore we display the concentrations from the Project Manager.

pictures/Ch-imod-tutorials/mt3d-check-SCO-benzene.png

Figure 11.209: Add the Starting Concentration of Benzene to the iMOD Manager.

Now we will import a nice Legend to display all concentration files in this tutorial. Therefore we open the iMOD Manager.

Feel free to have a look at other topics in the TreeView of the Project Manager.
The next important step is to use these model parameters to define and run an MT3D model. Therefore we need to choose the model type and set the time and space dimensions in the Simulation Manager. The next steps guide you through this process.

Because this is an MT3D model, additionally we must select a MODFLOW flux field from an existing MODFLOW model.

Now you set the Time and Space dimensions.

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Figure 11.210: Transport Timesteps for the MT3D model every 2 years.

Now we are ready to start the modelrun. The modelrun will take 3 minutes so let’s run the model in the background.

The model is running on the background to we can already start to examine some of the results in 3D, or actually 4D.

First we will assign a similar legend to all IDF files. We select one, and copy the legend that we assign to that one, to the others, so:

Now we copy the legend (colors) to all other IDF files.

We now synchronized all legends among the selected IDF files. Just try it out by selecting one of them and draw them via the Draw button ( pictures/h1-h3/image146.png) on the iMOD Manager window. Okay, now we start the 3D tool to visualise them in 4D.

iMOD starts to look for all files within the same folder as the selected IDF files whether there are more equivalent files (files that differ in date-signature only). Once it has finished gathering those, it will present the minimal- and maximal time window from which you can select. We select all available times (2071 files).

Your image might look like this.

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Figure 11.211: Example of a time-freeze during the 4-D visualisation.

You can restart the 4-D visualisation, or you can select one of the listed time-steps on the dropdown menu underneath the list of IDF files. You even can apply the clipping-planes to cut-open the voxels and examine there interior. Apply your knowledge on the 3-D Tool usage to explore the options furthermore.

That’s it for now! We close the 3D window.