Create drainage analysis surface from USGS data in Infraworks

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• Infraworks is capable of processing larger data sets. Therefore it is sometimes easier to consume DEM files, LiDAR files, or other large sets of data in Infraworks instead of working directly in Civil 3D. Once the data is inside Infraworks, smaller sample surfaces can be exported to Civil 3D.
• Another advantage to consuming data in Infraworks is coordinate transformations. Infraworks will automatically transform data to project specific coordinate systems. Then, when that data is exported to Civil 3D, it will appear in the correct location.
• WisDOT employees can have Infraworks installed on their workstation by contacting the IT service desk. http://dotnet/it/serviceportal/redirect.htm
• In this exercise, we will be using the same USGS data obtained in the surface from USGS data training topic. Download the project dataset to follow along. Alternatively, the dem data can be obtained from the national map viewer. http://viewer.nationalmap.gov/viewer/
• In this example, we are going to download a topographic quad map and load it into the model. Aerial images can also be used.
  • https://www.topoquest.com/find/state.php?state=WI
  • Download the Dallas and Dorrity Creek Maps

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1. Start Infraworks
2. Under Model, select New.

   

3. Since the Infraworks model will only be used for consuming data, we recommend that the Infraworks project be kept on the users' C-drive. Infraworks projects can grow quickly in size and take up unnecessary server space.
4. Name the project the project ID and provide a descriptions such as the highway name and project title.
5. It is important to define the model extents when practical. The model extents limit the Infraworks model to the area of interest. Without model extents, the Infraworks model will include the entire planet and performance would suffer. However, since the Infraworks engine can process large data, the model extents can be set significantly larger than the project. There are several options for setting the model extents:
   • Option 1: One way to obtain coordinate values for the model extents, is to open the project mapping file in Civil 3D. Choose minimum coordinates representing a point southwest of the expected area of interest. Choose maximum coordinates representing a point northeast of the expected area of interest.
   • Option 2: The simplest way to set the model extents is with the data that will be consumed. By clicking on the Load Extents From File button, you can select the data that will be brought into Infraworks. The extents will be set automatically based on the spatial limits of the data.

In this example, we'll select the .adf file from our USGS DEM download. These extents will be much larger than what we will need. However, we can reduce the model extents later.

6. Under Advanced Setting, there are some options regarding coordinate systems. These can be left as the default even if they do not match your project coordinate system. The UCS coordinate system can be changed to the project coordinate system if you wish. This will display the project coordinate system in the model. For our application, there is no need to change the database coordinate system.

   

7. Click Ok to create the model.

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To navigate the model, hold the left mouse button down to orbit. Hold the right mouse button down to pan. Use the wheel to zoom in and out. To return to a top view with north up, hover the cursor over the viewcube and click on the home symbol. This is the default view for the home view. The home view can be changed if desired by click in the down arrow next to the view cube.

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1. We can now begin to load data into the model. We recommend that you load an image file (or files) that encompasses the area of interest first. In this example, we are going to download a topographic quad map and load it into the model. Aerial images can also be used.
   • https://www.topoquest.com/find/state.php?state=WI
   • Download the Dallas and Dorrity Creek Maps
2. To load the images into the model, just drag and drop the image files (one at a time) into Infraworks.
   • Under the geolocation tab, there should not be any edits that are needed. The coordinate system of the image should automatically load.
   • Under the Raster tab, there are no required edits. However, since in this example we are loading a topographic quad map, we can change the classification to Topographic Map.
   • We recommend that you check the Clip to Model Extent box for all data loaded into Infraworks.

     

   • Click the Close & Refresh button

3. In this example, the area of interest spans 2 topographic quad maps. Repeat the previous step to load the second map. Now we can refine our model extents before loading our terrain data. From the Infraworks menu, select Model Settings. Under Extent, we can interactively define the model extents with a bounding box or polygon. Select the one that you prefer. For bounding box, first left click on one extent corner in the model. Next, double left click on the other extent corner in the model.
4. Click Save and then Click Close. The model extents are now refined.
 

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1. The process for loading terrain data is the same. Drag and drop the USGS .adf file into the model.
2. Under the Raster Tab, it is important to check the Clip to Model Extent box for terrain data.
3. Click Close & Refresh

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• Terrain themes
  • Terrain Themes can be a very useful tool for analysis. Under the Analyze Tab, select Terrain Themes. Click the green plus button to add a theme. You can make your own theme, or choose one of the preset themes. To access a preset them, click the palette type drop down menu. For USGS DEM files, the USGS National Map palette can be very useful. More than one theme can be loaded if desired.
  • Once a theme is added, it can be toggle on and off or edited. A common useful edit is transparency. This allow you to view the images loaded into the model at the same time as the terrain theme.
• Surface layers
  • If more than one image is loaded and they overlap, the order can be adjusted to view one or the other in the overlap area. In the example, the 2 topographic quads overlap. To switch which image is on top, click the Manage Surface Layers button from the home tab. In the dialogue, the images can be turned on and off and reordered.
• Visual effects

  • To adjust the visual effects, such as lighting, go to the Visual Effect tab. One common effect modification is the Light intensity. Often, the light intensity is set too high for optimal viewing of the topographic quad maps. Gradually slide the light intensity down until desired effect is achieved.

• Terrain exaggeration

  • For flatter terrain, it can be difficult to distinguish watershed boundaries. Exaggerating the terrain in Infraworks can quickly reveal these boundaries. To exaggerate the terrain, right click on the .adf file under the data sources. Choose configure. In the geolocation tab, set the exaggeration under the z scale. In the example, we exaggerate by 5. Click Close & Refresh. Since the terrain has been exaggerated in the z direction, you may need to zoom out to bring it back into view. Also note, that new terrain themes will need to be added for the exaggerated data.

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1. To export the terrain to Civil 3D, go to the Infraworks menu. Select Export – Export IMX
2. Define the area of the model that you want to export using either a bounding box or polygon. If the model size is not large, the entire model can be exported. We recommend exporting only the area that is required. The exported area remains dynamic with the Civil 3D surface that is create. The Civil 3D surface reads the .imx file in its definition. Therefore, if the .imx file is updated the Civil 3D surface will update.
3. Set the target file/location to the Civil 3D project directory. N:\PDS\C3D\ProjectID\BaseData\Other\USGSDEM\USGS-DEM-ProjectID.imx
4. Click Export
5. Open Civil 3D. Save a new drawing called N:\PDS\C3D\ProjectID\BaseData\Other\USGS-DEM\USGS-DEMProjectID.dwg

6. Insert Tab - Import Panel – Import IMX. Select the IMX file.
7. The surface will automatically be created and named AIM_Existing_Ground. Give the surface a logical name such as Exist-USGS-DEM
8. If the surface extents need to be updated, just re-export the IMX file from Infraworks with the new extents. Overwrite the previous IMX file. The Civil 3D surface will update.

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• The exported area remains dynamic with the Civil 3D surface that is creates. The Civil 3D surface reads the .imx file in its definition. Therefore, if the .imx file is updated the Civil 3D surface will update. If it is discovered that a larger (or smaller) area is needed for the Civil 3D surface, redefine the export extents in Infraworks.
• If the surface extents need to be updated, just re-export the IMX file from Infraworks with the new extents. Overwrite the previous IMX file. The Civil 3D surface will update.