[POC] Remove richdem/gdal from tests

[adebardo]

Context

The goal of this ticket is to permanently remove dependencies on richdem and gdal in the xDEM project to simplify its installation.

Implementation

Currently, these dependencies are used in the tests and serve only as ground truth for terrain attributes.
We will therefore precompute these values and load them for the tests.

richdem

• Create the following ground truth data using richdem and store them in tests/ground_truth_data:
  • slope_Horn
  • aspect_Horn
  • hillshade_Horn
  • curvature
  • profile_curvature
  • planform_curvature
• Load them using rasterio in the test_terrain file
• Use them as ground truth
• Update the configuration files accordingly

gdal

Same process as above for:

• slope_Horn: (slope, Horn)
• aspect_Horn: (aspect, Horn)
• hillshade_Horn: (hillshade, Horn)
• slope_Zevenberg: (slope, Zevenberg)
• aspect_Zevenberg: (aspect, Zevenberg)
• hillshade_Zevenberg: (hillshade, Zevenberg)
• tri_Riley: (TRI, Riley)
• tri_Wilson: (TRI, Wilson)
• tpi: (TPI, None)
• roughness: (Roughness, None)

[rhugonnet]

All good for me!
Regarding where we could move the files, maybe the repo xdem-data where the current example data lives? The repo could include the gdal/richdem scripts to generate the attributes, that we would re-run only when we add new DEM example data in that repo, or if we choose to force a manual re-run?
Doing this, there would be almost no change on the xdem repo, as we already bulk-download all xdem-data files (if they don't already exist locally) during test execution using the existing routine here.

[adebardo]

It's a good idea, but if we add a dependency on RichDEM to the code, then you can no longer distribute xdem-data under the MIT license.

[rhugonnet]

I hadn't thought of that 😵.
We couldn't make the case that it is ultimately used only for dev/testing, like we did for xDEM, and ignore the license issue with RichDEM?
Or, as long as it's not transitive to xDEM (as used only for testing and documentation), we could also change the license of xdem-data, I don't think that'd be an issue.

[adebardo]

GlacioHack/xdem-data#2 just in case