Tutorial #2: Run Simulation

The SWAT model is ready to run after opened in SWAT Viewer. There are two options for the simulation run: simulation engine and output time step. The simulation engine could be any of the standard SWAT version or a customized version. The output time step could be daily, monthly or yearly. In SWAT Viewer, these options are available in Scenario View by selecting the scenario in the Project Explorer.

This video covers the process to run a simulation in SWAT Viewer. Also talked about the model output format. The format used in SWAT Viewer make it much easier to post processing the outputs and run and compare different engines on same scenario.

Run a simulation: 00:38

The output format : 7:15

Simulation Options

Simulation Options 2

You have the options to select the engine and the output time step when you run the model.

  • Model Engine: The model engine could be the standard SWAT engines or any customize engines. It’s available from the engine list.
  • Output Time Step: The output time step could be daily, monthly and yearly. There are three button for each time step. It will basically change IPRINT in file.cio.
  • Open Model Files: You may want to make the final touch before you run the simulation. There are few buttons you could use to open specific model files (file.cio, basin.ban and fig.fig) directly. Or you could open the model folder using the Open Model Folder button.

Model Outputs

Result Database

The traditional SWAT model outputs are in multiple files with same names. They will be overwritten after each simulation run. In SWAT Viewer, we want to enable to compare the outputs from different engines on same model. So the model outputs has been changed to single database with unique name so it will not be overwritten by simulation runs using different engines and time steps.

This single database approach also eliminate the need to convert the output files to a database for post-possessing which will save you significant amount of time.

Other Related Videos

Tutorial #1: Open SWAT Project show you how to open a ArcSWAT, QSWAT and MWSWAT project in SWAT Viewer.

Add Modified SWAT version to SWAT Viewer shows the way to view the results of your modified SWAT version in SWAT Viewer.

Compare SWAT versions in SWAT Viewers shows you how to compare the outputs from different SWAT version in SWAT Viewer.


9 thoughts on “Tutorial #2: Run Simulation

  1. Hallo Michael,
    I would like to use a modified swat version in the OutputViewer. I want to adjust my model to the tropics and I am using SWAT-T therefore. Here is the article about this version:
    Alemayehu, Tadesse; van Griensven, Ann; Woldegiorgis, Befekadu Taddesse; Bauwens, Willy (2017): An improved SWAT vegetation growth module and its evaluation for four tropical ecosystems. In: Hydrol. Earth Syst. Sci. 21 (9), S. 4449–4467. DOI: 10.5194/hess-21-4449-2017.
    The authors provide an exe-file to use in SWAT in the supplementary. If I understand your video currectly, I still have to make some changes for OutputViewer, though. Is that assumption correct? Can you help me how to adjust it to be applicable in the OutputViewer? I would appreciate it very much.
    Kind regards,

    • Hi Johannes,

      Thanks for reaching out. Yes, as mentioned in the video, the viewer use a modified engine to have output in a database. This needs to be integrated to your modified version. So, you need the source code from them so I could do the integration. I understand it may not be possible. We will see what we could do once confirmed from them.


      • Hi Michael,
        The modified subroutines are available online (or is something else needed in addition?). I can send them also to you. If you find the time to integrate them it would be great, but of course, I don’t want to bother you too much. So if it is not complicated and time consuming, this would be really nice.

      • Hi Johannes,

        If you could send me the link to the source code, I could have look. It may not need long time to do the integration. Could I know you purpose of your research?


      • Hi Michael,
        here is the link given in the paper:
        Of course, I want to investigate soil erosion at Mount Kilimanjaro at HRU level and wanted to get realistic life cycles of the vegetation (e.g. bananas, coffee, evergreen forest, range land).

      • Hi Johannes,

        I got the source code and it won’t take long to integrate the code to be used with SWAT Output Viewer. I should be able to send you something this weekend if you could give me your email address.


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s