SWAN GIS Post Processing
This page describes how to use the post processing tools in the SWAN GIS plugin. The plugin offers an interface for basic post processing of SWAN model results. With the standard SWAN distribution, grid files can be output as either MAT or text files. The interface offers a tool for processing the MAT file output format to a more user friendly netCDF4 output format. It also offers a tool for extracting point time series files from a netCDF4 output file.
Converting SWAN MAT Outputs to NetCDF4
Start QGIS (version 3.16.3 or later). Under the plugins menu, navigate to the plugins/TUFLOW/SWAN GIS Tools/Post Processing tab:
By default the output NetCDF will be saved where the original MAT result file was output by SWAN. The SWAN GIS plugin automatically post processes the NetCDF4 file to the same location and uses the same name, just replacing the file extension.For example:
Extracting Time Series from netCDF4 Result File (Optional)
As an optional extension item, to investigate wave conditions at different locations in our model we can extract a timeseries from our SWAN output results.
- input the SWAN NetCDF4 result file noting that if you have MAT files you will need to use the converter first.
- Input the output file path for the CSV file time series.
- Create a new CSV file in C:\Tutorial_Module_SWAN_GIS_Tools\Moreton_Bay_Waves\QGIS called POINTS_XTR_000.csv.
- Open the CSV file in a text editor and add the below entries as shown. These are the points where time series will be extracted.
Name X Y POINT_01 153.637 -27.477 POINT_02 153.283 -26.877
- Set the points file input to the newly created CSV file.
- Press the 'Extract' button to execute the time series extraction. Once complete, navigate to the output path. Separate files would have been output for each input point.
You have now worked through the post-processing options available in the SWAN GIS Tools. You can now return back to the main tutorial page.