Synthesizing changes in low flows from observations and models across scales
Synthèse des changements sur les étiages depuis les observations jusqu'aux modèles à différentes échelles
Résumé
This contribution presents a comparison of the observed and projected low flow trends and changes for the European domain (as derived from homogenized large-scale datasets and model applications) with the mosaic of results obtained from pan-European and national-scale studies. The large-scale datasets include the streamflow records held in the European Water Archive and the WATCH large-scale model ensemble. National studies are available from Norway, the UK, southern Germany, Austria and France. The comparison shows that large-scale model experiments focus mostly on the general pattern of seasonal flow changes, whereas national to regional scale studies tend to focus on absolute low flow values and deficits below relevant thresholds and often stratify their assessments by hydrological regime or dominant process control. The study concludes that different levels of information can indeed benefit synthesis assessments of low flow changes at the hydrological planning scale.