Abstract. Recent climatic changes have the potential to severely alter river runoff, particularly in snow-dominated river basins. Effects of changing snow
covers superimpose with changes in precipitation and anthropogenic modifications of the watershed and river network. In the attempt to identify and
disentangle long-term effects of different mechanisms, we employ a set of analytical tools to extract long-term changes in river runoff at high
resolution. We combine quantile sampling with moving average trend statistics and empirical mode decomposition and apply these tools to discharge
data recorded along rivers with nival, pluvial and mixed flow regimes as well as temperature and precipitation data covering the time frame
1869–2016. With a focus on central Europe, we analyse the long-term impact of snow cover and precipitation changes along with their interaction
with reservoir constructions. Our results show that runoff seasonality of snow-dominated rivers decreases. Runoff increases in winter and spring, while discharge decreases in
summer and at the beginning of autumn. We attribute this redistribution of annual flow mainly to reservoir constructions in the Alpine ridge. During the
course of the last century, large fractions of the Alpine rivers were dammed to produce hydropower. In recent decades, runoff changes induced
by reservoir constructions seem to overlap with changes in snow cover. We suggest that Alpine signals propagate downstream and affect runoff far
outside the Alpine area in river segments with mixed flow regimes. Furthermore, our results hint at more (intense) rainfall in recent
decades. Detected increases in high discharge can be traced back to corresponding changes in precipitation.
Long-term changes in central European river discharge for 1869–2016: impact of changing snow covers, reservoir constructions and an intensified hydrological cycle
