Aquaveo & Water Resources Engineering News

Eliminate Null Values in SMS

Does your Surface-water Modeling System (SMS) model contain null values? Null values can be useful at times. Some models are even built around them. But what about when you don’t want them in your model? The tools in the Toolbox have ways to change, correct, or exclude data, including null values, without needing to manually edit the files and re-importing them, to clean up the data. These tools have multiple uses for viewing data in different ways, modifying current datasets, and creating new ones from the modifications made.

The Toolbox holds a very useful option in the Filter Dataset. It can be used to modify data in existing datasets by using various filters to include, exclude, or change the data being processed. When you have null values inside your project that you wish to exclude, you can use this tool to eliminate null values and assigning them to 0.

In order to use the Filter option, follow these steps:

  1. Go to Toolbox | Dataset | Filter Dataset.
  2. Click on Run Tool…
  3. Under Input dataset, select the dataset from the dropdown.
  4. For the If condition, select null from the dropdown.
  5. For Assign on true, select Specify from the dropdown.
  6. Enter 0.0 for the Specified Value.
  7. Under Output dataset, enter a new name for the results of the test.
  8. Click OK to run the tool.
Example of the Filter Dataset tool

Once you have created a filtered dataset, the new dataset can then be viewed in the simulation or used with other tools in the toolbox to modify, view, or create other new datasets for better visualization.

This filter function can also be found under Data | Data Set Toolbox… under the Tools section in the left-hand column. It has a slightly different look but the exact same utility.

Head over to SMS and try out the Filter tool to see how it can improve your model results and data visualizations.

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Streamlining GMS by Using Keyboard Shortcuts

No matter how long you have been using the Ground-water Modeling System (GMS), you can enhance your experience with keyboard shortcuts. GMS comes equipped with various keyboard shortcuts–quick keys, hotkeys, accelerator keys, keybindings–in order to make the process more efficient for you. Whether you are just beginning or seasoned, such shortcuts are useful for any water modeling project.

The newest addition to the collection is related to the GMS unstructured grid (UGrid) feature, and facilitates progress with one click: Select all cells in UGrid layer using the “l” (L) key.

New select UGrid layer shortcut

Here are a few more shortcut options that expedite the groundwater modeling process:

  • CTRL+D (Display Options): Quickly populate your display options module for view and modification.
  • CTRL+F (Frame Image): Use this option to scale and frame your model in the Main Graphics Window.
  • View: Utilize these options and view your project from any perspective quickly.
    • Shift+P (Plan View)
    • Shift+F (Front View)
    • Shift+S (Side View)
    • Shift+O (Oblique View)

With all of the intricacies of the GMS software, simplifying even the smallest commands may increase productivity in infrastructure planning:

  • CTRL+N (New Project): Clear the contents of your previous project easily with this command.
  • CTRL+O (Open File): Import a new file with this command.
  • Delete Key: Delete objects easily with this command.
  • CTRL+A (Select All): Select all objects easily with this command.
  • CTRL+U (Unselect All): Unselect all objects easily with this command.

Mastering keyboard shortcuts is a key aspect of becoming a proficient user of GMS. By taking advantage of these time-saving tools, users can navigate the environmental engineering software more efficiently, focus on their modeling tasks, and ultimately achieve better results in their water modeling projects. Use the "GMS Keyboard Shortcuts" article on the Aquaveo wiki to view these commands and more.

Additional shortcuts continue to be added to GMS. Access the latest version of GMS to make use of the newest shortcuts today!

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Discover MODRAT Percent Impervious

When working with the Watershed Modeling System (WMS) and the MODRAT model, one potential aspect of your watershed analysis would be determining the percent impervious values for each sub-basin. Accurate percent impervious calculations may significantly influence your hydrologic modeling outcomes. Here is a guide to help you navigate this process effectively.

Importing Land Use Data

To compute the percent impervious for each sub-basin in MODRAT, you need to start with accurate land use data. Land use data in WMS is typically stored in the GIS and Map modules. The most efficient way to read this data into WMS is through a shapefile. Here’s how you can do it:

Example of the Map MODRAT Attributes dialog
  1. Create a Land Use Coverage: In WMS, start by creating a new land use map coverage. This coverage will hold all the land use data you import.
  2. Import the Polygon File: Import your land use polygon shapefile into WMS. This file should contain various land use types and their respective boundaries.
  3. Assign the Percent Impervious Field: Ensure that the percent impervious field, often labeled as IMPERV_ by the Los Angeles County Department of Public Works (LACDPW), is correctly mapped to the LA County Soil land use field in WMS. This step is crucial as it links the impervious data to your land use coverage.
  4. Compute and Assign Percent Impervious: With the land use data now present in WMS, use the "Map Attributes" command in the MODRAT menu to compute and assign the percent impervious values. This function will analyze the land use data and calculate the percent impervious for each sub-basin.
Using Coverage Overlay Options

Another method to determine the percent impervious values is by using the Coverage Overlay options in WMS. This approach is similar to calculating curve numbers and involves overlaying land use coverage with drainage coverage.

  1. Overlay Land Use and Drainage Coverage: Start by overlaying your land use coverage with an existing drainage coverage. This will combine the datasets, allowing for an analysis of land use types within each drainage area.
  2. Calculate Percentages: The overlay will provide you with the percentages of different land use types within each sub-basin.

Whether you choose to import land use data directly or use the coverage overlay options, both methods can aid in determining the percent impervious. Use either method in your MODRAT projects in WMS today!

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