Learning from the past
Pan-European Analysis of Historic
Large-scale Droughts
Development of a pan-European drought reference database
Key features of two major drought
events analyzed in Drought-R&SPI
Drought of 1976
•  Slow onset attributed to
accumulated precipitation deficit
from the previous winter
•  Drought centered in central
Europe, as high pressure system
diverted rainfall to the North Sea
and the Mediterranean
Europe has experienced several dry and hot summers in the 21st century, notably the record
breaking 2003 event covering a large part of central Europe, and more regional events during
the summers of 2005 through 2007. Unlike many other natural hazards, droughts may persist
for long periods and affect large areas, often impacting many countries. It is therefore
important, for consistency and scope, to analyze drought at the pan-European scale. An
improved understanding of drought will allow for better drought forecasting, identification of
drought sensitive regions, and development of drought management policies.
A European database of major historic drought events is being developed as part of the
Drought-R&SPI project to study the underlying processes and impacts of drought in a consistent
manner. By applying consistent metrics across different hydroclimatic regimes, drought events
may be compared with respect to onset, severity, persistence, and recovery.
These
climatological and hydrologic metrics will be linked to a database of economic, social, and
environmental impacts also being developed under the Drought-R&SPI project, forming a
reference set for further investigations.
•  Estimated €5 billion in losses
(EurAqua 2004)
Drought of 2003
•  Rapid development caused by an
acute lack of summer rainfall and
accompanying heat wave
•  Drought centered in central and
southern Europe, as hot, dry air
masses extended from Northern
Africa
•  Estimated €11.6 billion in losses
(EurAqua 2004)
Low flow at Pont du Gard, River
Gardon, August 2003
(Photo: Henny van Lanen).
Why were these two events
selected?
•  These events were selected as two
of the largest and most severe
European droughts in the past 50
years in terms of spatial coverage
•  The events differ in location and
temporal development
Monthly progression of the 1976 drought event (1/3/1976-1/10/1976). The 3-month accumulated
climatic water deficit (precipitation – evapotranspiration) anomaly (SPEI_3, Vicente-Serrano 2010)
is shown in the upper and lower rows, with red representing excessive dryness and blue
representing excessive wetness. Runoff anomaly (middle rows) is shown with red, orange, and
yellow corresponding to the 10%, 20%, and 30% non-exceedance levels, respectively, based on the
daily runoff median of nine large-scale hydrologic model simulations run using WATCH forcing
data.
Learning from the past
Pan-European Analysis of Historic
Large-scale Droughts
Progression of the 2003 drought event at 4 month intervals (4/2003-12/2003). Red cells represent excessive dryness accumulated over the
preceding 6 months, measured by Standardized Precipitation-Evapotranspiration Index (SPEI). Blue cells indicate an excess of wetness.
The 1976 and 2003 European Drought Events
Drought-R&SPI
Project participants responsible for
analysis of large scale drought
University of Oslo (UiO) [Lead], Norway
ETH Zurich (ETH), Switzerland
University of Freiburg (ALU-FR), Germany
Wageningen University (WU), The
Netherlands
Flier prepared by James Stagge (UiO), Lena Tallaksen (UiO),
Kerstin Stahl (ALU-FR), Lukas Gudmundsson (ETH), and Anne
van Loon (WU).
References
EurAqua (2004) Discussion Document: Towards a
European Drought Policy.
Fischer, E.M., Seneviratne, S.I., Vidale, P.L., Lüthi, D.
& Schär, C. (2007) Soil moisture-atmosphere
interactions during the 2003 European summer heat
wave. J. Climate 20, 5081-5098.
Perry, A. (1980) Dominant Pressure Patterns. In: Atlas
of Drought in Britain, J.C. Doornkamp, K.J. Gregory,
and A.S. Burn (Editors). Institute of British
Geographers, pp. 14.
Schär, C. & G. Jendritzky (2004) Hot news from summer
2003. J. Climate 432, 559-560.
Stahl, K. & Hisdal, H. (2004) Drought hydroclimatology.
In: Hydrological Drought – Processes and Estimation
Methods for Streamflow and Groundwater, L.M.
Tallaksen and H.A.J. van Lanen (Editors). Development
in Water Sciences, pp. 19-51.
Vicente-Serrano, S.M., Beguería, S. & López-Moreno,
J.I. (2010) A Multiscalar Drought Index Sensitive to
Global Warming: The Standardized Precipitation
Evapotranspiration Index. J. Climate 23, 1696-1718.
The 1976 and 2003 drought events allow a comparison between an event with a slowly
accumulated moisture deficit (1976) and an event with a more acute lack of summer rainfall,
with an accompanying heat wave (2003).
The 1976 event was brought about by a relatively dry, mild winter with below average
precipitation. This precipitation deficit, centered in France, the UK and Scandinavia,
accumulated slowly over several months and grew into a severe summer drought across Central
Europe when abnormally high pressure centres diverted much of the rain-bearing depressions
either far north or south into the Mediterranean region (Perry 1980). Abnormally hot, dry
conditions continued until cold air was advected over Scandinavia in August, breaking the
pattern and forming a large, low pressure zone over the Continent.
In 2003, a high pressure system developed over western Europe, blocking moist air from the
west and allowing warm, dry air masses from northern Africa to extend northwards into
Europe. This resulted in a summer heat wave, with mean June-August temperatures exceeding
the 1961-90 mean by over 5° C (Schär et al. 2004). Abnormally high temperatures, in addition
to an early spring greening and positive atmospheric-soil moisture feedback, contributed to a
significant increase in evapotranspiration and drought conditions across most of central and
southern Europe (Fischer et al. 2007). Record low streamflow and groundwater levels were
reported in addition to record high water temperatures for several European rivers (Stahl and
Hisdal 2004).
Other Major European Drought Events
Period
Region/Countries Affected
1976-­‐77
Western Europe
1981-­‐82
Iberian Peninsula (Portugal, Spain, Southern France, Corsica, Italy)
1988-­‐91
1992-­‐94
Mediterranean Region (Portugal, Spain, Southern France, Italy, Albania, Greece)
Eastern Europe (Germany, Denmark, Poland, Lithuania, Hungary, Former Yugoslavia, Ukraine, Moldova)
1992-­‐95
Spain
2000
Central Europe (Romania, Hungary, Poland, Bulgaria, Greece, Former Yugoslavia, Czech Rep, Turkey, Germany)
2003
Europe (Romania, Hungary, Poland, Bulgaria, Greece, Former Yugoslavia, Czech Rep, Austria, Switzerland, Italy, Germany, Belgium, Denmark, Netherlands, Norway, UK, France, Spain, Portugal)
Based on EurAqua (2004)