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FUTURE IMPERFECT
but with an increase in the north, especially in the
north-east (Figure 7).
The seasonal trends show even larger spatial differ-
ences (Figure 8). We can detect wetter and dryer ar-
eas in each season, but overall increasing precipita-
tion is found in winter and summer, while a decrease
happens in spring.
While climate models suggest a north-south gradient
in the region, observations support a west-east gra-
dient for the precipitation trends, caused mainly by
drying in the western part of the region. Comparing
the observational and modelled trends, clear differ-
ences can be detected especially in summer (Fig-
ures 8 and 9). Model results show less spatial vari-
ability and present more unified patterns than the
measurements. There are also temporal differences,
especially in summer. Models show summer drying
that is not supported by observations. The investigat-
ed time interval is not the same, but they are quite
close to each other (1961-2010 and 2016-35 rela-
tive to 1985-2005), which leads to the conclusion
that differences cannot be explained by the different
time periods.
According to the reports of the Intergovernmental
Panel on Climate Change (IPCC), more intense pe-
riods of precipitation can be expected. Despite the
decreasing amount of precipitation, heavy rainfalls
©
Green Dossier
can happen more frequently, and they can be more
intense. While the maps of precipitation totals and
tendencies show large spatial variability, the inten-
sification of precipitation is quite consistent. Inten-
sification can be described by several indices and
parameters. Increasing intensity and decreasing
number of wet days lead to more runoff and less
infiltration. This worsens the surface water balance,
reducing water safety and increasing erosion. All
these effects require water management adapta-
tion measures.
With respect to more extreme events, the number of
hot days is increasing, whereas extreme cold tem-
perature values are decreasing. Figure 10 shows