Specifying Arc Lengths in SMS 13.2

Imagine yourself trying to get an arc in an SMS map coverage just the right length. You keep on moving around the endpoint, but that often moves its azimuth as well. What’s more, measuring the arc would require using the Measure tool, and maybe that’s not precise enough for you. Fortunately, the most recent release of SMS has a solution. Today, we take a closer look at the Specify Arc Length tool, a tool designed for helping you be detailed in creating arcs. This tool, which was released as part of the beta of SMS 13.2, enables you to extend or shorten an arc by a specified length.

Let’s say that you have drawn an arc, and it’s pretty close to what you wanted, but you would prefer it just a little longer. You could manually adjust it, but using the Specify Arc Length tool, you can make it exactly the length you prefer.

Here’s how:

  1. In the Map module, select the Select Feature Arc tool.
  2. Select the arc you want to modify.
  3. Right-click and select the Specify Arc Length command.
  4. In the Specify Arc Length dialog, specify the desired arc length in the New Arc Length section.
Example of the Specify Arc Length in SMS

If the desired arc length is longer than arc’s current length, then the arc extends to match the entered length. If the desired arc length is shorter than the arc’s current length, then a new node is created to shorten the arc. Shortening an arc results in the creation of two arcs.

There are some important things to keep in mind when using this new tool.

First, the arc can only be adjusted relative to the arc direction, which is usually the direction the arc was drawn (e.g. right to left) when it was created. This means extending the arc moves the end node of the arc in a straight line in the arc direction until the whole arc is the desired length. Shortening the arc adds a node the specified distance along the arc in the arc direction. This can be seen in the image below. The beginning of the arc (usually the node drawn first) never moves as a result of the Specify Arc Length tool.

It’s also important to be aware of the arcs attached to the arc you’re modifying. If the arc is attached to another arc, then extending the arc also modifies the length of the arc it is attached to. Be sure that adjusting both arc lengths is desirable before using this tool.

Furthermore, when extending an arc with many segments, note that only the segment at the end of the arc gets extended. The final segment extends in a straight line as shown below until the arc is the specified length. The rest of the segments are left untouched.

This is just one of the many tools that SMS13.2 makes available to enhance your water modeling capabilities. Try out using the Specify Arc Length tool in SMS 13.2 today.

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Rebuilding an SRH-2D Restart File

Have you ever needed to rebuild an SRH-2D restart file for a project you were working on? Perhaps you lost the restart file or maybe you made modifications to your mesh, so the restart file is no longer valid for the model you have. Regardless of the cause, rebuilding a restart file can be a vital step in completing the model you're working on.

To start rebuilding your restart file, see if you can do a dry run of your simulation:

Example of the SRH-2D Model Control Set to Use a Dry Run
  1. Right-click on the simulation in the Project Explorer and select Duplicate.
  2. This ensures that the original simulation is preserved if needed.
  3. In the newly-created simulation, right-click and select Model Control to open the Model Control dialog.
  4. In the dialog on the General tab, for the Initial Condition drop-down select "Dry".

Every run of SRH-2D creates restart files for the model. Initially, it creates a restart file for every time step as determined by the Output Frequency in the Model Control dialog. However, when the solution is loaded into SMS, the software only saves the restart file for the final time step. If a restart file for a different time step in the simulation is desired, then please complete the following before clicking Load Solution in the Simulation Run Queue dialog:

  1. Browse to where the project is saved.
  2. Double-click on the folder with the same name as the SMS project.
  3. Double-click on the SRH-2D folder.
  4. Double-click on the folder with the same name as the simulation run.
  5. This is where restart files were written for every time step. The file that ends in "_TSO.dat" is a text file with information about which restart files correspond to each time step. Open it in a program that can read plain text files to make sure that you select the restart file with the desired time step. The restart files end in "_RST" followed by the time step number (e.g. "Standard_Run_RST12.dat").
  6. Once you have determined the restart file you want to save, copy and paste it in a different folder on your hard drive.
  7. Then click Load Solution in SMS.

SMS loads the results into SMS and keeps only the restart file for the final time step. It's important to remember that changing anything in the mesh necessitates the creation of a new restart file. Restart files should only be used with a model that uses the exact same mesh as the simulation that generated the restart file. Using the restart file with a slightly modified mesh might yield inaccurate results.

SRH-2 with SMS provides powerful tools for surface-water modeling. Use SMS today!

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Trimming and Extending Arcs in SMS 13.2 Beta

Do you have arcs in a project that you need to extend or trim to match another arc? For example, you may be modeling a bridge with two arcs to represent the bridge in SMS. If you want to make certain the two arcs are the same length, you will need to extend or trim one of the arcs. A new tool introduced in SMS 13.2 allows you to trim or extend the length of arcs to match the length of another arc. This article will discuss how to trim or extend arcs as well as the advantages of doing so.

To use the Trim/Extend tool, do the following:

  1. Select one arc and, holding down the Shift key, select another arc. It is important to take note of what arc IDs are selected, trimming or extending the wrong ones can cause problems in the model.
  2. Right-click and select the Extend or Trim Arc command to open the Trim/Extend Arc tool.
  3. In the tool, there are two different options: one to select the arc that will be extended or trimmed and another option to select which arc will be used as the base arc for the length.
Example of Trim/Extend Arc in SMS

There are a few ways to differentiate between wether you are extending or trimming an arc. With the extend option, the number of intersections included in the arc selection will indicate to the tool to use the "extend" operation. Whereas with the trim option, if one or more intersections are included in the selection, this indicates a "trim" operation. This will allow a node to be inserted into the first arc at the first intersection and delete the first portion of the newly split arc.

It should be noted that you can only select up to two arcs otherwise the option to trim or extend will not appear. Try trimming or extending arcs in SMS 13.2 beta today!

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Merging Map Coverages in SMS

Do you have an SMS project that might benefit from merging coverages together? It’s not uncommon to have feature objects on different map coverages in SMS that would be useful to have on one coverage. For example, you might have feature objects from a shapefile on one coverage that you would like to merge with feature objects you have created on another coverage. This post will cover some tips to merge coverages as well as the effects of merging coverages.

To merge map coverages:

  1. Select one coverage in the Project Explorer then hold down the Ctrl key and select another coverage.
  2. Next right-click and the Merge Coverages command will appear.
  3. After clicking the Merge Coverage command, a warning dialog will ask you if you want to keep or delete the coverages being merged.
  4. Upon completion a new merged coverage will appear in the Project Explorer.
Example of Merging Map Coverages in SMS

Merging coverages comes with a lot of benefits when working with a large number of feature objects. When merging coverages here are a few items to keep in mind:

  • When merging coverages of different types, the new merged coverage will be converted to the Area Properties type.
  • When merging coverages of the same type, the new merged coverage will be the same type. For example, if you had two map coverages that are both ADCIRC materials they are going to remain ADCIRC Materials after they have been merged together.
  • When merging, only the feature objects will be merged together–any defined attributes on the feature objects will be reverted to the default setting for that coverage type. For example, the default for SRH-2D boundary conditions coverage type is the wall boundary condition. When two SRH-2D boundary condition coverages are merged all the arcs will be set to have the wall attributes.
  • When only wanting to copy a few feature objects from one coverage to another, use the Copy to Coverage feature instead of merging entire coverages.

These are just a few tips to help with merging coverages in SMS. Try out merging coverages in SMS 13.2 today!

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