Aquaveo & Water Resources Engineering News

Do you have an SRH-2D project that is going to take a long time to run? If you don't want your computer tied up for hours, or even days, an SRH-2D project can broken up into smaller model runs that build on each other. This is done by using a restart file or hot start file.

In SRH-2D, a restart file can be specified for the initial wet/dry condition of the simulation. The restart file must have been generated from a previous simulation run that used the same mesh. Several output options exist for creating restart files including: creating them at a regular interval, at a specified list of times, or a single restart file at the end of the simulation.

When SRH-2D does a model run, it creates a series of files for each time step. These restart files are named [casename]_RSTn.dat where n corresponds to the time index. The time series output index file is named [casename]_TSO.dat and holds a list that matches the restart files to a specific time step.

When a restart file is used as an initial conditions hot start file, the previously computed hydraulic conditions from the restart file will always be applied to the start time of a simulation.

To use a hot start condition, do the following:

1. Run an SRH-2D simulation to completion.
2. In the output files for the model run, locate the file ending with "TSO.dat" and open it in a text editor.
3. In the TSO file, locate the time step where you want to use to start your next next simulation run.
4. In you SMS project, duplicate your simulation.
5. Open the SHR-2D Model Control dialog for your new simulation.
6. In the Initial Conditions section, select the Restart File option.
7. Press the Select button to browse to your restart file.

SRH-2D will now use the conditions from the restart file when you perform your next model run. Now that you know how to use a restart file for an initial condition in SRH-2D, try it in the Community Edition of SMS today!

Need to predict direct runoff or infiltration from rainfall excess? Computing a curve number (CN) is a common solution to this problem. The curve number method was developed by the USDA Natural Resources Conservation Service using empirical analysis of runoff from small catchments and hillslope plots.

To calculate a CN you will need the hydrologic soil groups, land use data, and rainfall conditions for a given area. You then need to enter the values for the CN equation to get your final values. While you could calculate a CN manually, WMS can do the work for you.

1. Import data for the area, either as map coverages or as GIS data. It is import that you review this data for accuracy before using it to compute a curve number. Required data includes land use data and soil type data.
2. Create a land use ID table file. This can be done in any text editor and should be saved as a standard text file. Examples can be found in the XMSWiki and in the TR-55 manual.
3. Make the Hydrologic Modeling module the active module.
4. Select the Compute GIS Attributes command in the Calculators menu.
5. In the Compute GIS Attributes dialog, select the SCS Curve Number option.
6. Select the coverage or GIS layers to use for the calculation.
7. Import the land use table file by clicking the Import button and selecting the land use table text file.
8. Once your options are set, click OK to generate your curve numbers.
9. If needed, in the View Data File dialog, select the text editor to use to see your final curve number results. This dialog may not appear if a default text editor has been selected.

Now you can review the curve numbers in your text file. Try calculating Curve Numbers in WMS Community Edition today!

It happens. You‘ve finished building your SRH-2D model in SMS and you launch the model run. Then, to your dismay, SRH-2D stops running and gives you an error.

It’s not fair. You did everything correct and entered all the correct parameters. SRH-2D should be running and giving you its valuable results. But instead you have an error message.

Don’t panic.

While it is discouraging for SRH-2D to not complete when you launch the model run, it is only telling you that a key bit of data is missing for it to give you valid results. The error code will help you locate that data or fix an inconsistency.

But how do you use the error code to find what needs to be fixed? And shouldn’t the SMS model checker have found it before SRH-2D started?

The SMS model checker verifies all the data needed to run SRH-2D is present and looks for errors in the SMS project such as dangling arcs, numbering issues, or missing components. It does not validate the data. Once the SMS model checker has finished, SRH-2D performs its own checks during the model run.

When SRH-2D gives you an error, you’ll need to record the error number. Errors are shown in the model wrapper. Clicking on the Pre-SRH-2D button will show if there are errors during the pre-processor run. Clicking the SRH-2D button will show errors during the model run.

Once you know what the error is, you can look up the list of SRH-2D errors on the XMSwiki here. The article contains a list of known errors along with guidance on how to fix them.

If you were unable to record the error from the model wrapper, don’t worry. You can still see this information by reviewing two of the files generated by SRH-2D during every model run. These files will be named [projectname].OUT.dat and [projectname].DIA.dat files.

To use these files:

1. Locate the files in the model run directory with your project file.
2. Open the *.OUT.dat or *.DIA.dat files using a text editor such as Notepad.
3. Look through the text file to locate the error code.
4. Go to the SRH-2D error page to find the solution.
5. Make the needed change(s) to your project and run SRH-2D again.

Typical solutions to SHR-2D model run errors might involve adjusting some data inputs or making minor reconfigurations to boundary conditions or structures. While making these changes to a project can sometimes be frustrating and tedious, getting an accurate end result will make it all worthwhile.

Need to open your project data in Google Earth? GMS can do that by generating a KMZ file from your project data.

GMS allows creating either a raster KMZ file or a vector KMZ file.

Raster KMZ File

This option saves the project data as an image with georeferencing data. The data is clipped to match the current view in the Graphics Window.

To create the file:

1. Switch to Plan View.
2. Check that you are using geographic coordinates, otherwise it may be distorted.
3. Use the File | Save As command.
4. Set File of Type to be "Google Earth Raster KMZ File (*.kmz)".
5. Select the Options button to set the resolution.

When pulled into Google Earth, a raster KMZ will simply display the file data as an image over the georeferenced location.

Vector KMZ File

This option saves the project data as vector information. All visible data in the Graphics Window will be included. Points, lines, and polygons will be saved in the file along with the georeferenced data.

1. Switch to Plan View.
2. Use the File | Save As command.
3. Set File of Type to be "Google Earth Vector KMZ File (*.kmz)".

When imported into Google Earth, a vector KMZ will contain an image over the georeferenced location, along with a layers for any lines, points, or polygons contained in the file. These layers can be toggled on or off.

Transient Data

Transient data in GMS can be exported as a raster KMZ file animation.

1. Switch to Plan View.
2. Check that the project is using global coordinates.
3. Select the Display | Animate command.
4. In the Animation Wizard, turn on the KMZ file option.
5. Set the options for where to save the file and what parameters to use.

After GMS generates the animation, you can open in Google Earth to see the results.

Now that you’ve seen how KMZ files can be generated, go ahead and give it try in GMS today.