Tutorials:2 Visualizing Overland Flow Results

This tutorial is compatible with:

• WMS Version 8.1 and later
• GSSHA Version 3.0b and later
  
  

Disclaimer: GSSHA tutorial exercises do not represent real world conditions

Working with Results

Since we have just run our first simulation, it would be nice to see what happened! You’ll notice that after you hit close on the Model Wrapper that WMS automatically read in some files. WMS stores the results of a run together as a solution set (the input data is not a part of the solution, only the output data.) There can be many solution sets in the data tree but they must be for the same grid and streams. For example, you could have solution sets for different roughness parameters or different time steps and then you can compare results across the data sets. If you are just starting at this tutorial, first load the initial project:

1. In the 2D Grid module , select GSSHA™ | Open Project File
2. Browse to the basic_ov.prj file in the Finished_tutorial\basic_ov folder of the GSSHA™ tutorial folder.
3. Hit Open.
   
   
   In order to open a project you must select a *.prj file. The project file is the primary file that tells WMS and GSSHA™ what options are set up and which files should be read or written. The project file lists both the input files as well as the output files that GSSHA™ will read and write during a run. Thus the project file doubles as the solution file. In order to open the solution (if you did not run GSSHA™ in the previous chapter or you are starting over):
   
   
4. Select GSSHA™ | Read Solution…
5. Make sure that the simulation points to the right simulation (basic_ov.prj in this case.)
   
   
   Notice that beneath the Select Simulation button WMS has a line that says “Solution file: GSSHA™ Solution files found.” What this means is that WMS has opened the project file listed above, read in what should have been the output file names, tried to open those files, and found at least one that exists. If you have not run the simulation yet or GSSHA™ was not able to run, then the dialog will say that the solution files are not found.
   
   
6. Select OK.
7. Expand the ‘new grid’ 2D grid folder in the data tree
8. Expand the ‘basic_ov (GSSHA™)’ folder.
   
   
   Notice that on the ‘basic_ov (GSSHA™)’ folder icon, there is an ‘s’ for solution. Now that we have a solution read in we can do many things. First, though, let’s look at the summary file.
   
   
9. Double-click on Summary File under the solution folder.
10. If WMS asks for your editor just click OK.
11. Look through the summary file. It is good to check things like mass balance and the volume remaining on the surface.
12. When you are done you can close the window.
    
    
    From the summary file we learned that most of the water remained on the grid instead of running off. There could be a couple of reasons for this. Maybe the simulation did not run long enough, or there are problems with the elevation grid, or both. Let’s look at the water depths to determine what happened during the run.
    
    
13. In the 2D Grid module select Display | Display Options
14. Turn on the 2D Grid Contours.
15. Select OK.
16. In the data tree, right-click on Depth under the solution folder.
17. Select Contour Options.
18. Under Contour Method select 'Color Fill.'
19. Select OK.
    
    
    Underneath the data tree a set of time steps appear. Click around on a few. It would be helpful if we knew what the colors represented.
    
    
20. Right-click on Depth in the data tree.
21. Select Contour Options.
22. Turn on the legend.
23. Click OK.

Creating a Movie

Click around some more on the time steps. Try panning, zooming, and rotating. You can also adjust the lighting (Display| Display Options | Lighting Options) and the vertical exaggeration (Display | View | Z Magnification.) Let’s make a movie of the contours. Once you get a view that you like:

1. In the 2D Grid module select Data | Film Loop…
2. Make sure that Create New Film loop and Scalar/Vector Animation are selected. Hit next.
3. Turn on the Depth Scalar Data Set. Hit Next.
4. Hit finish. Wait for WMS to build the movie.

Once the movie is created and playing you can adjust the playback speed, looping, etc.

Now that we have a movie of the runoff depths, it is fairly easy to see that the water has stabilized by the end of the run to sit in many little puddles on the grid. These puddles are the result of the digital dams. Thus our lack of runoff is not due to time constraints (currently, anyways) but due to the presence of digital dams.

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