Connecting watersheds to outlet points in unnest basins

[williamlidberg]

I am not sure if this is a fitting suggestion but here goes.

I have a large DEM containing 2 000 lakes to which I want to extract watersheds. I could either loop over all lake outlets one by one or use the tool unnest basins. Unnest basins is sweet since it only needs to read the DEM into memory once instead of 2 000 times. However, I still need to connect the watersheds with the outlet points somehow. Giving the resulting watershed an ID that contains some info from which outlet points would be helpful. Perhaps an option to name an attribute ID field that will be used for naming watersheds. Alternative, adding an option to print out a list containing input point name and output watershed name.

[dankovacek]

Given a shape file with many pour points, the unnest_basins function produces a series of rasters containing non-overlapping polygons describing the full input pour point set. Subsequently running the raster_to_vector_polygons function on the resulting rasters yields vector files containing a VALUE parameter that matches the input pour point index.