Hi @rxchelzhxng,
Sorry for the confusion! Service.built is in $ * m^3:
Affected.build ($) * R_m3(m^3)
This is a kind of strange unit because it is an indicator of the value, not an exact measure. You can think of it like a unitless index. See the discussion here: Service.built - UFRM model
The documentation is incorrect there where it says just m^3. I’ll correct that.
Regarding the spatial resolution, the two raster inputs are aligned and resampled if needed so that they both have the same pixel size as the original landcover raster. You can see these aligned rasters in the output temp_working_dir_not_for_humans folder. The “runoff retention per pixel” really means “pixel-wise runoff retention”: This is a unitless ratio for each pixel representing the fraction of water on that pixel that’s retained. So the spatial resolution does not affect the values of the output, just the precision:
pixel area (m^2) * runoff retention (unitless) * rainfall depth (mm) * 0.001 (mm/m) = retention volume (m^3)
I hope that helps!