ReFH2.3 does not currently use any of the catchment descriptors released in 2025: feh-catchment-descriptors
Please do not use SAAR9120 or URBEXT2015 in place of the descriptors ReFH2.3 currently uses (SAAR6190 and URBEXT2000). The ReFH2.3 model was developed and calibrated using SAAR6190 and URBEXT2000 and should only be run using these. The newer descriptors are not consistent with these thus using these would be inappropriate.
The BFIHOST19scaled uses the same coefficients as BFIHOST19, where the ‘water’ classification has been removed and the remainder soil classes used to estimate the BFI. In most catchments BFIHOST19 and BFIHOST19scaled will be the same or very similar. They can differ where the catchment has storage, which a low FARL value can indicate.
ReFH2.3 does not try to account for storage within the catchment. As a general rule, it may therefore be appropriate to use BFIHOST19scaled rather than BFIHOST19. The appropriate choice will depend on the catchment, the study and how the results will be used.