SMS

Utilizing Data Modification Tools in SMS

The Dataset Toolbox in SMS allows viewing your data in many different ways, while also being used to modify and create new datasets from already existing datasets. The different tools in the toolbox each use a specific set of functions to modify selected datasets.

One tool in the Dataset Toolbox that can prove to be helpful is the Filter tool. This tool creates a new dataset based on the selected filtering criteria.

For example, say you are filtering your numeric model output to show depths between the minimum and maximum depth, then you wish to filter the depth data for velocity between minimum and maximum range. This tool could help to show how a fish habitat changes over time or for any other purpose you can think of.

There may be multiple ways to accomplish this task, but one method would be to filter the velocity dataset to the desired range and then map that activity to the depth dataset. Using this example, you could do the following:

  1. Open the Dataset Toolbox.
  2. Select the Filter tool.
  3. Use the tool to filter the Velocity Mag dataset to the desired range and apply NULL outside the range.
The Filter tool in the Dataset Toolbox

The Map Activity tool is another tool that can be helpful. This tool maps the activity from one dataset to a second dataset. It helps show only the values of interest on a particular dataset. To continue the previous example:

  1. Select the Map Activity tool in the Dataset Toolbox.
  2. Using the dataset created in the previous steps, map the activity from the new dataset to the depth dataset (Value Dataset).

The new dataset will appear in the Project Explorer, showing the values of interest. If the dataset is a transient then a film loop could be made, showing how it changes over time.

The Filter and Map Activity tools are only two of many tools available in SMS’s Dataset Toolbox. Try out these tools and others in SMS today!

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Viewing Flood Extents in SMS

For many riverine projects, finding areas of potential flooding is a key component. SMS offers a few ways to see the flood extents in a given project.

When running a riverine numeric model, such as SRH-2D, a dataset of the water surface elevation (WSE) is often part of the resulting solution. Using the contours and time steps of the WSE dataset can help locate the flooded areas and extents within the modeled area.

You can use the “max” function in the data calculator to make a dataset showing the maximum water surface elevation across all timesteps. For example, using a WSE dataset, you would enter "max(WSE:all)" to get the maximum value for the WSE dataset across all time steps. This would then show the maximum extents.

A faster way to view floodplain data for a single time step is to use the Map Flood command. This tool utilizes ground elevations and existing flood hazard maps from the Federal Emergency Management Agency (FEMA) to quickly visualize the impacts of possible modifications in the flood level. The Map Flood tool works with FEMA flood hazard data allowing you to avoid building and running an entire numeric model in order to obtain a quick estimate of the flood areas for a single time step.

Flood Extents using Map Flood

The Map Flood tool can also be used for a single time step with local data for areas where FEMA data is not available. More information about the Map Flood tool is found in the Fast Floodplain tutorial.

You can share the flood data you’ve generated by exporting a WSE or max WSE dataset in a variety of file formats using either the right-click Export command or the File | Save As command. The feature arcs created using the Map Flood can also be saved as a shapefile or any other available file format.

Try out the tools in SMS for viewing flood extents today.

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Importing and Exporting Shapefiles

If you have data in GMS, SMS, or WMS that needs to be shared with another application, one of the easiest ways to share this data is through shapefiles. GMS, SMS, and WMS can all import and export shapefiles, though there are some differences between them. This article goes over some of those differences.

Importing Shapefiles

When you import shapefiles into GMS, SMS, or WMS, they will be loaded under the GIS module. Shapefiles can be imported just like any other file using the File | Open command, the Open File macro, or dragging the file icon on the interface. From there, you can use the conversion commands to move the shapefile data into other modules.

Exporting Shapefiles

Though GMS, SMS, and WMS have a lot of similarities they each vary from the other when it comes to saving a shapefile. In general DEMs, TINs, feature objects, and grids can be saved through the right-click menu in GMS; the file menu in SMS; and through both the right-click menu and file menu in WMS.

GMS
Export command

Shapefiles can be exported through the right-click menu.

  1. Right-click on the item in the Project Explorer and select Export to bring up the Export dialog.
  2. In this dialog you can change the "Save as type" to "Shapefile (*.shp)".

The following items can be exported as shapefiles.

  • TINs
  • 3D Grids
  • Feature Objects
  • DEMs
SMS

Shapefiles can be exported through the File menu.

  1. Select the item in the Project Explorer, then File | Save As to bring up the Save As dialog.
  2. In this dialog you can change the "Save as type" to "Shapefile (*.shp)".

The following items can be exported as shapefiles.

  • Scatter Sets
  • 2D Grids
  • Feature Objects
  • Raster Files
WMS

Shapefiles can be exported through the right-click menu and through the File menu.

  1. Select the item in the Project Explorer, then File | Save As to bring up the Save As dialog.
  2. In this dialog you can change the "Save as type" to "Shapefile (*.shp)".
  3. Alternatively, you can right-click and select Save As to bring up the same dialog.
The following items can be exported as shapefiles.
  • TINs
  • 2D Grids
  • Feature Objects
  • DEMs

Now that you know a little more about using shapefiles in XMS, try using them in your GMS, SMS, or WMS projects today!

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Understanding Projections vs. Reproject

Have you ever wondered what the difference between projection and reprojection is? Have you ever needed to convert a projection from one type to another in GMS, SMS, or WMS (collectively known as XMS)? The use of projections in WMS can be confusing, so the following should provide further clarification.

Specifying Projections

Projections can be associated with individual data objects, either in the object data file itself or in an associated *.prj file. If XMS cannot find a projection, the object will be left as "no projection," or, when new objects are created, XMS will assign the display projection to it. You can specify an object's projection by right-clicking on it and selecting Projection. Note that this projection must be the same as the original projection of the data; specifying an incorrect projection will result in data issues.

Reprojecting on the Fly

"Reprojecting on the Fly" occurs when datasets or objects from multiple projections are loaded into a project, where the x and y values would not otherwise overlap (i.e., the data would be displayed in two or more distinct locations). The different projections for these data will be "reprojected on the fly" to match the display projection such that the data objects will line up. Note that this does not change any *.prj files or the projections that are set for each object; it is an automatic function internal to XMS used for display purposes.

Converting a Projection

If you need to convert from one projection to another, this can be done by right-clicking on it and choosing Reproject. To use this command, the data must first have the correct projection specified. After choosing Reproject, the command will prompt the user to select a new projection, the data will be converted to the selected projection. If a *.prj file is associated with the object (such as a TIFF), reprojecting the object will change the *.prj file. Reprojection on the fly is usually sufficient for most applications. Please note that there are some limitations for reprojecting.

Reporject Dialog Example

Once the datasets are referencing their projection correctly, XMS should reproject them on the fly to match your display projection. If you don't have a display projection set, you can do so by selecting the Display menu and choosing Projection. At that point, if you would like to reproject your scatter(s) into the same projection as the display projection, you would be able to do so.

Now that you see the differences between projection vs. reproject try them out in XMS today!

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