Aquaveo & Water Resources Engineering News

3 Ways to Troubleshoot WMS Basin Issues

Have you noticed your model’s basin isn't what you hoped it to be? When you create a solid watershed model, there are a few common issues that can make the model not work as intended. These include:

  1. Having a flow accumulation threshold that is too low or too high.
  2. Having one or more outlets in the wrong location for proper definition of the sub-basins and basins.
  3. Trying to work with a project area that is too large or too small for the intended purpose.

Flow Accumulation Threshold

Setting the correct flow accumulation threshold is very important. If you set the flow accumulation threshold too low, it may not accurately show the information you need, leaving sections of the watershed model reporting dry conditions. If you set it too high, you can be overwhelmed with too much information. It is good practice to try multiple levels to see which provides the most accurate results for the project. You can adjust this setting by doing the following:

  1. Open the Hydrological Modeling Wizard dialog.
  2. Select Compute Flow Directions and Accumulations (TOPAZ) from the list on the left.
  3. Enter the desired Min flow accumulation threshold and close the dialog.

Adjusting the Outlet

Placing an outlet in the wrong location causes the entire structure of the stream system to change dramatically. This can produce sub-basins quite different than desired, which can lead to results not lining up as expected. Remember that everything upstream from an outlet will be part of the same sub-basin or basin, so be careful when placing your outlets for each sub-basin as well as for the full basin.

Project Area

Sometimes, you may select a larger area than necessary for your model, or you may select an area too small for the project to produce useful results. If the area is too large, the desired details may not show up in your results. If the selected area is too small, you may not have enough data on which to base your decisions for the watershed.

If you keep these ideas in mind, your watersheds will better represent the areas you're modeling. Experiment with this today in the WMS Community Edition.

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Stockholm GMS Training 2018

Aquaveo recently taught a three-day GMS training session hosted by the School of Engineering Science at the KTH Royal Institute of Technology in Stockholm, Sweden. The institute’s Prosun Bhattacharya arranged and coordinated the training session.

From May 15-18, 2018, Alan Lemon and Hoang Tran presented on a wide range of topics, including general groundwater modeling concepts, using MODFLOW in GMS using both grids and conceptual models, incorporating field data (such as scatter point and borehole data) into a GMS project, and calibrating models in GMS. Models demonstrated and discussed include MODFLOW, MODFLOW-USG, MODPATH, MT3DMS, and SEAWAT.

Participants came from several different countries, companies, and governmental and non-governmental organizations, including:

There were also graduate students from Gdańsk University of Technology in Poland, and KTH Royal Institute of Technology and Luleå University of Technology in Sweden.

After the classes, Alan and Tran enjoyed walking around Stockholm and seeing the sights, including the Vasa Museum and the Nobel Museum.

Aquaveo provides custom, on-site training for SMS, GMS, WMS, ArcHydro Groundwater, and any other water resource modeling need you have. Organizations can set up shared trainings such as this one, or arrange for the same training for their own employees. You can learn more about our training offerings by visiting our site.

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Using an SRH-2D Restart File

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!

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Draping an Image onto a Ground Surface

When looking at your GMS project in oblique view or when using the Rotate tool, you might have noticed that your map image will disappear. This is because GMS only supports viewing map images in plan view. However, there is a way to make the map image visible in these views.

The ability to drape an image in GMS has been around since the early versions. However, you may not have had an opportunity to use it, or you simply missed hearing about it among all the other great things GMS does.

When not in plan view, an image can be draped on the top surface of a TIN, mesh, or grid. When this is done, the map image will remain visible even when rotating the display view. Some relationships between the surface texture and the shape of the terrain can become visible after the image has been draped over the terrain surface.

If you didn’t already know how to drape an image in GMS, or you want a refresher on how to do it, this is what you do:

  1. Turn off Ortho Mode if it is active. Draping an image cannot be done using Ortho Mode.
  2. Select and make active the map image you want to view. You can use any image file type that GMS can import.
  3. Select a dataset under your grid, mesh, or TIN in the Project Explorer and make it active. A draped image is only applied to one dataset at a time.
  4. Open the Display Options dialog.
  5. Select the appropriate grid, mesh, or TIN display tab.
  6. Turn on the Texture map image option.
  7. Use the Rotate tool or any of the view options to see how the image mapped to the top surface of the geometry.

Here’s an example of how it will appear:

If desired, you can adjust the Lighting Options in GMS to make the features smoother or sharper.

Now that we’ve reviewed the steps, try draping images in GMS today using the GMS Community Edition.

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Computing Basin Curve Numbers in 9 Easy Steps

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!

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Converting a NET File to an INP File

Do you have an EPANET project you are wanting to import into CityWater?

When working on a municipal drinking water pipe network, EPANET is a water distribution model created by the U.S. Environmental Protection Agency that is widely used by cities and towns all across the United States. However, not all programs can use the native EPANET project file format. Because of this, you may find yourself needing to convert the standard NET file used for EPANET projects into an INP file that can be imported into CityWater.

The NET file is a binary file format containing all the pipe networks information, including pipes, nodes (junctions), pumps, valves, storage tanks, and reservoirs. It also contains additional project and preference information used by the EPANET desktop application.

INP files are the plain text version of the NET file, and contain the same network information (EPANET 2 Users Manual, pp.128-129). The INP file format allows greater flexibility in how the pipe network is used, and it can easily be imported into CityWater and other programs such as WMS.

The first steps are to:

  1. Download the EPANET installation program (currently version 2.00.12) from the Environmental Protection Agency's EPANET website.
  2. Once the installer has downloaded, run the installation program.

Once the EPANET application is installed, use the following steps to convert your NET project file to the INP text format by doing the following:

  1. Launch the EPANET application.
  2. Open the NET project file in EPANET.
  3. Review the model to make certain the project is set up as you want it, including quality options and default settings.
  4. Select Export > Network... to bring up the Save Network As dialog.
  5. Browse to the directory where you wish to save the INP file.
  6. Enter the file name you wish to use (e.g., Filename.inp) and click Save.

The INP file can now be imported easily into CityWater as the base file for a new project.

Try this out today by converting your NET files and creating new projects in your CityWater project.

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Troubleshooting Errors in SRH-2D

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.

Community Edition of SMS.
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Community Pinewood Derby

Recently, Aqauveo’s Provo office participated in a Pinewood Derby race with several other local companies. For those unfamiliar with the sport, it involves racing small wooden kit cars down a track. The tradition in Cub Scouting was begun nearly 65 years ago in Manhattan Beach, California.

As anyone familiar with the pinewood derby can attest, it requires some engineering know-how to create a speedy car from a block of wood. Getting the proper shape for the car, placing the correct amount of weight in the right location on the bottom of the car, and establishing the correct wheel balance and alignment are all important factors to consider. All of this is done to make the cars go as fast as possible without them wobbling off the side of the track or skidding along the edge of the track.

The other companies participating included HadCAD, Charity Vision, Jones T-Shirts, Link Trust, Alpha Solar, and Sawtooth Software.

Around a dozen cars were entered, and each ran four races--one on each track. The slowest time was discarded and the car with the fastest average time won. Two of the cars employed 3D printing: a red one with a full 3D printed shell that fit snugly over the top of the base wooden block, and a Batmobile with a 3D printed airfoil and Batman figure. One of the most creative was a car designed to look like a pinewood derby car on a track.

We had two entries from Aquaveo employees: a silver and black car designed by Gage Larsen (Testing Manager), and a red and blue car designed by Steven Estep (Technical Support). Steven’s car finished in 6th place overall.

We look forward to another race next year.

Exporting Raster and Vector KMZ Files

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.

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2 Ways to Import ArcGIS Files into WMS

ArcGIS software has long been a standard in generating geographic data. It is likely you will have received a shapefile generated in ArcMap at some point. ArcGIS files can be imported into WMS to save you time in recreating geographic data.

There are two main methods for importing ArcGIS data: through the standard open dialog or through the GIS module.

Standard Method

To import ArcGIS files into WMS:

  1. Select the Open command in the File menu.
  2. Make certain the Files of Type field is set to "All Files" or "Shapefiles".
  3. Browse to your file and open it.

That’s all you need to do. You can also use any other standard methods for opening files such as using the Open macro or dragging the file onto the Graphics Window. There is also a command to open shapefiles in the Data menu in the GIS module.

Right-clicking on the the imported shapefile in the GIS module allows joining table and layer data. This data can then be mapped onto a coverage using the Shapes → Feature Objects command in the Mapping menu.

A grid coming from ArcGIS will be imported as a DEM in the Terrain Data module . A TIN will also be imported into the Terrain Data module.

GIS Module

When the GIS Module is active, you can use commands to directly import ArcGIS data into WMS. To do this:

  1. Make certain the GIS module is active.
  2. Select the Data | Add Shapefile Data command.

  3. or

  4. Select the Data | Add GIS Data command.
  5. Use the file browser to locate your files and import them.

This second method is useful for a wider range of ArcGIS data files. If a file does not open correctly using the standard methods, then importing the file through the GIS module is recommended.

DEMs and TIN files opened through the GIS module will be imported into the GIS module instead of the Terrain module.

Take a look at what other GIS tools are offered in WMS.

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