Our water resources have changed over the last century through a
combination of water management evolutions and climate change.
Understanding and decomposing these drivers of discharge changes is
essential to preparing and planning adaptive strategies. We propose a
methodology combining a physical-based model to reproduce the natural
behavior of river catchments and a parsimonious model to serve as a
framework of interpretation, comparing the physical-based model outputs
to observations of discharge trends. We show that over Europe,
especially in the South, the dominant explanations for discharge trends
are non-climatic factors. Still, in some catchments of Northern Europe,
climate change seems to be the dominating driver of change. We
hypothesize that the dominating non-climatic factors are irrigation
development, groundwater pumping and other human water usage, which need
to be taken into account in physical-based models to understand the main
drivers of discharge and project future changes.