Why is the content of this map important?
Since projected climate change is expected to potentially lead to higher evapotranspiration over large parts across Europe, it is fundamental to study how this will impact streamflow droughts. This is of interest for adaptation planning for various sectors (see next point below).
Which sectors are affected by this result?
Several sectors are affected by streamflow droughts including power generation (power plants cooling), fisheries and water suppliers.
What is shown on the maps?
Streamflow droughts deals with low flows in rivers, as opposed to meteorological and agricultural droughts. The specific kind of streamflow drought is the 1 in 100 year return one: a streamflow drought which occurs on average every 100 years. In parts of southern Europe (Greece, Spain, Portugal, part of the Balkans, France and Italy), streamflow droughts are expected to be more intense due to less rainfall and higher water evaporation. In parts of Fenno-Scandinavia and eastern Europe (Poland, Hungary), such droughts shall be less intense. This is due to: firstly, less snowfall and more precipitation in areas with low flows in winter, and secondly, for areas with low flows in summer, a general increase of rainfall.
Details and further information:
These results are based on 2 hydrological models outputs and 5 high-resolution climate models. The information for the reference and the +2°C global warming periods are given in m3/s (cubic meters per second). The relative change is expressed in percentages (%). A positive increase refers to more water in the river channel, such that a drought appears to be less intense.
Based on their skills to simulate the extreme events, 2 hydrological models have been selected estimate extreme floods (Lisflood and E-Hype). These models were driven by the ensemble of the five mandatory climate simulations. Hence, the ensemble consists of 10 simulations in total.
The calculations are carried out and depicted only for the grid points where the output of all hydrological models is available.
Philippe Roudier
Joint Research Center - European Commission (JRC), Italy