resample methods in to_model_ds

[tomvansteijn]

When modelling a large area it can be necessary to coarsen the grid beyond the default 100 m resolution dictated by the REGIS dataset. The method to_model_ds uses resample.ds_to_structured_grid, using nearest neighbour interpolation by default (the argument is not set).

I think it would be useful to have other scaling methods for the hydraulic conductances, such as the mean and harmonic mean. Have you considered to implement these in nlmod?

[OnnoEbbens]

I agree that it would be nice to have this in nlmod. We have not yet implemented this. If you use the update_ds_from_layer_ds function there are more resampling methods than just nearest neighbor (example here: https://nlmod.readthedocs.io/en/stable/examples/12_layer_generation.html). However the harmonic mean is not yet an option in update_ds_from_layer_ds.

For geotop we use the arithmetic weighted mean for kh and a harmonic weighted mean for kv by default. So it would be nice to implement this logic for scaling in the update_ds_from_layer_ds function.