iMOD User Manual version 5.2 (html)

11.18Tutorial 17: iMOD-WQ SEAWAT

This tutorial presents how to use the SEAWAT functionality in iMOD-WQ applied to a simple model. More information about variable density flow modelling can be found in the SEAWAT manual ([Langevin et al.(2008)]).


This is what you will do:

Required Data

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

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 will model the evolution of a freshwater lens which develops because of a constant natural recharge. The aquifer only contains saline groundwater at the beginning of the simulation.

The TreeView ALL tab shows all the topics that can be used in iMODFLOW and iMOD-WQ, however, we would like to only see the ones related to SEAWAT. This is done via the following steps:

This project file already has some packages included. Nonetheless, there are still some missing packages which we will add now. We will start with the Starting Concentration (SCO) package.


Figure 11.212: Activating the Starting Concentration (SCO) in the iMOD Manager.

In this window we can define the location of the chloride files to be used. These are already available in *.idf format.


Figure 11.213: Location of starting concentration files.

Now we are going to display the just imported information.

The next step is to import the Concentration Boundary indicator (CBI) or ICBUND files. The procedure is similar to the one used previously to import the Starting Concentration (SCO) files.

Finally, we will add the information for the Variable Density Flow (VDF) package, which is a specific SEAWAT package.

It is possible to add other packages to define further system processes by following the previously shown steps.
For now let us save the project file including the added info for parameters SCO, CBI and VDF.

The next step is to use these model parameters to define and run a SEAWAT model.

Note: Known issues: iMOD-WQ cannot handle yet a ’space’ in the name of the result folder. The name must have the type Character so it should contain at least 1 character. Be aware of that!


Figure 11.214: Selection of SEAWAT model in the Simulation Manager window.

Interested in saving the fluxfiles like BDGFLF of BDGRCH, select the topic (BND) Boundary Condition.


Figure 11.215: Simulation Manager - Temporal configuration and Actual Stress Period Configuration

Now we are ready to start the model run.

The next step is to open the model results.

For a better visualization of the final model results we will import an appropriate legend file.

To see how the concentrations vary over time, we have to follow the next steps.


Figure 11.216: Model output.