Impact studies of the hydrological response of future climate change are important for the water authorities
when risk assessment, management and adaptation to a changing climate are carried out. The objective
of this study was to model the combined effect of land use and climate changes on hydrology for a
486 km2 catchment in Denmark and to evaluate the sensitivity of the results to the choice of hydrological
model. Three hydrological models, NAM, SWAT and MIKE SHE, were constructed and calibrated using
similar methods. Each model was forced with results from four climate models and four land use scenarios.
The results revealed that even though the hydrological models all showed similar performance during
calibration, the mean discharge response to climate change varied up to 30%, and the variations were
even higher for extreme events (1th and 99th percentile). Land use changes appeared to cause little
change in mean hydrological responses and little variation between hydrological models. Differences
in hydrological model responses to land use were, however, significant for extremes due to dissimilarities
in hydrological model structure and process equations. The climate model choice remained the dominant
factor for mean discharge, low and high flows as well as hydraulic head at the end of the century.