How to load 2D model results

The following points provide guidance through the Flood Modeller operations to get from a TUFLOW or 2D model to a generic flood map or animated flood event.

  1. 2D Model results data are saved in a specific raster format. This is compatible directly with Flood Modeller.
  2. The 2D results data are loaded by selecting the standard load data option, Add GIS Data, and browsing to the required 2D data management file (extension is .2dm or .sup or xmdf.sup). Depending upon which file type is selected the loading procedure is slightly different, as described below:
  1. If all available time steps are loaded from your 2D model results then you can select any time step to display in the map view from the list of available time steps which is displayed in the Time Steps tab in the right hand side panel of the interface. It should be noted that in addition to the real time steps, some pseudo time steps will also likely be present within your dataset. These are all signified by time flags that begin with “9999” and are defined as follows:

These extra time steps will be ignored by Flood Modeller when you animate your data (as they are not “real” time steps). They are available to visualise in the map view and can be output as separate ascii grid layers using the 2D Flood Calculator tool.

  1. Other layers (for example map tiles, aerial photographs and topography grids) can then be loaded using the Add GIS Data command, to facilitate greater understanding of the results.
  2. The Properties menu (accessed by right clicking the layer in the Layers panel) can be used to change the colour scheme used for the results. Predefined colour schemes can be loaded in, and result grids can be further manipulated to increase the clarity of the results, e.g. make partially translucent, edit colours to highlight particular data ranges (such as threshold exceedance), etc. These can be found under the Symbology tab.
  3. If two or more time steps have been loaded then the results can be animated in Flood Modeller. To animate a 2D dataset select the animate option from the menu displayed when right-clicking on 2D data file in the Layers panel or by clicking the Animate Single Result button in the Results tab. The animation toolbar is then displayed at the top of the viewport. This offers the controls shown in the figure below:

  4. Animations displayed in the Flood Modeller can be recorded to movie using the record option in the animation toolbar. You can select video size and the frames per second setting.
  5. It may also be useful to save the results to a snapshot image file. The results can be saved to snapshot image files either for immediate printing or for use in other applications. This option is accessed from the menu displayed when right-clicking on the viewport (select Save Snapshot). You should ensure you have orientated the viewport to show the data the way you require before an image is saved. Also you should ensure that any other useful layers are loaded to enhance the image's representation of the flood extent.
  6. The Flood Modeller 2D Flood Calculator tool can be used to extract flood extents grids from the 2D Model / TUFLOW results data. These grids will be an alternative format to the 2D output grid: Format options available are ASCII (.asc) or Binary (.flt) grids, contour shapefile (.shp polygon), and Google earth format (.kml)

It should be noted that it is also possible to post-process ASCII grids with the trace outline to shapefile function (Layer Convertor in either the Grid Tools or Shapefile Tools sections of the Toolbox). This automatically draws an outline over only the outer edge of a flood extent grid. Thus, a much smaller file is produced; however the depth data of the grid is not retained. Furthermore, the Layer Convertor tool (Toolbox > Grid Tools or Shapefile Tools) can also be used to convert grid or shapefile format files into Google Earth format (kml).

Details of the operation of the 2D Flood Calculator tool are provided in Section How to use the 2D Flood Calculator.