Mountainous catchments are usually not in focus of the modelling of nutrient fluxes on catchment
scale. Out of 9 model approaches tested in the EU-project EUROHARP only MONERIS claims to be
capable of modelling nitrogen and phosphorus emissions in a landscape with mountainous slope. Results
derived in the present study indicate that the MONERIS 2.14 model in its current version is not able
to reproduce the measured nutrient loads in rivers from alpine catchments in Austria with a size of 70
to 400 km2. Despite this apparent limitation, MONERIS delivers a framework flexible enough to offer
the possibility for the introduction of adaptations to regions that had not been a focus during its development.
Significant improvements in model performance have been achieved during this study with
relatively simple adaptations: (i) calibration a snowmelt constants, (ii) adaptation of the nitrogen balance
for open and naturally covered areas, (iii) adaptation of the denitrification approach for groundwater of
solid rock areas with low nitrogen surplus and high amount of leakage water, (iv) introduction of the
differentiation of area-specific suspended solids emission factors for mountainous open areas covered
either with glaciers or not, (v) definition of new input parameters for phosphorus concentrations in
solid limestone and schist/gneiss rocks and of dissolved phosphorus concentrations in surface runoff
and groundwater flow for mountainous areas.