Climate change impacts and vulnerability in Europe 2016

Climate change impacts on environmental systems
4.3.4 Meteorological and hydrological droughts
Key messages
• Drought has been a recurrent feature of the European climate. From 2006–2010, on average 15 % of the EU territory and
17 % of the EU population have been affected by meteorological droughts each year.
• The severity and frequency of meteorological and hydrological droughts have increased in parts of Europe, in particular in
south-western and central Europe.
• Available studies project large increases in the frequency, duration and severity of meteorological and hydrological
droughts in most of Europe over the 21st century, except for northern European regions. The greatest increase in drought
conditions is projected for southern Europe, where it would increase competition between different water users, such as
agriculture, industry, tourism and households.
Relevance
Droughts have severe consequences for Europe's
citizens and most economic sectors, including
agriculture, energy production (see also Sections 5.3
and 5.4), industry and public water supply (Blauhut
et al., 2015). However, the term 'drought' is used in
different contexts, which may cause confusion when
the language used is not carefully chosen. Figure 4.13
shows how a persistent meteorological drought can
propagate to a soil moisture (agricultural) drought
affecting plant and crop growth, which may deepen
into a hydrological drought affecting watercourses,
water resources and natural ecosystems. Furthermore,
hydrological droughts have a detrimental impact on
freshwater ecosystems including vegetation, fish,
invertebrates and riparian bird life (EEA, 2012c, 2015,
2016a, 2016b). Hydrological droughts also have a
significant impact on water quality by reducing the
ability of a river to dilute pollution.
This indicator combines two types of droughts:
meteorological droughts and hydrological droughts,
focusing on river flow droughts in the case of
the latter. A meteorological drought is defined in
terms of precipitation deficiency, which may be
exacerbated by high temperature associated with
Figure 4.13
Drought types and causes
Meteorological situation
Anomalies in
precipitation
Anomalies in
evapotranspiration
Meteorological drought
Precipitation deficiency
Soil moisture drought
Low soil moisture
Hydrological drought
Low discharge
Low ground water level
Socio-economic drought
Impacts
Source: Adapted from Van Loon, 2015.
144 Climate change, impacts and vulnerability in Europe 2016 | An indicator-based report