Climate change and land cover changes are influencing the hydrological regime of our rivers. The intensification of the hydrological cycle caused by climate change is projected to cause more flooding in winters and an increased urbanization could amplify these effects by a quicker runoff on paved surfaces. The relative importance of both drivers, however, is still uncertain and interaction effects between both drivers are not yet well understood. In order to better understand the hydrological impact of climate variability and land cover changes, including their interaction effects, we fitted a statistical model to historical data over 3 decades for 29 catchments in Flanders, covering various catchment characteristics. It was found that the catchment characteristics explain up to 18 % of changes in river peak flows, climate variability 6 % and land cover changes 8 %. Interaction terms explain up to 32 %. An increase in urban area of +1 % might cause increases in river peak flows up to +5 %.