Roughness Height Raster

The Derive Associated and Error Surfaces tool generates surfaces used for analyzing Geomorphic Change Detection.

  1. Make sure you have the Channel Unit CSV file generated by the CHaMP Broker.
  2. Under the Topo Processing menu, select the Derive Associated and Error Surfaces tool.
  3. Make sure the correct Survey Geodatabase is open.
  4. Make sure that the correct TIN and Channel Unit CSV files are specified.

    This tool may take several minutes to run, especially for very large surveys.

  5. Click OK to Run the tool

There are no outputs that need to be reviewed. When you have generated the Associated and Error Surfaces, you may proceed to Generate a Thalweg.


Issue with Small Side Channels

In a small side channel, since occular estimates of substrate are not collected (per protocol), missing data in the csv is causing the tool to fail.

Temporary Workaround:

  1. Make a copy of the ChannelUnits.csv file in your topo folder
  2. Remove any lines that refer to the small side channels or are missing Occular Estimate Value.
  3. Save the file and then use this copy when running the tool.