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Workshop Disaster Risk ReductionBrussels, 29-20 October 2009
HYDROLOGICAL EXTREMES
Drought
Key Achievements and Challenges
Henny A.J. van Lanen
Jaroslav Mysiak
Richard Harding
Workshop Disaster Risk ReductionBrussels, 29-20 October 2009
Drought and Floods
Drought:
- larger spatial scale- longer temporal scale
than Floods
Stahl & Hisdal (2004)
Workshop Disaster Risk ReductionBrussels, 29-20 October 2009
Drought
Soil moisture deficit
Low flows and dried up rivers
Agricultural production
Forest fires
Low reservoir levels
Multi-hazard:
� fires
� heat waves
Multi-impact
� agriculture
� aquatic/wet ecosystems
� navigation
� energy production
� …
Workshop Disaster Risk ReductionBrussels, 29-20 October 2009
Key Achievements
TRENDS IN DROUGHT
Tallaksen &van Lanen (2007)
Is drought becoming more extreme?- meteorological drought (T, Prec, incl. snow)
- hydrological drought (groundwater, river flow)
Workshop Disaster Risk ReductionBrussels, 29-20 October 2009
Key Achievements
TRENDS IN HISTORIC DROUGHTS
Period: 1962-2004
sig. Neg. trends: 8.7 % sig. Pos. trends: 0.4 %
Stahl et al. (2008)
Timing of minimum flow (earlier, later,..)
About 600 small, undisturbed basins
Workshop Disaster Risk ReductionBrussels, 29-20 October 2009
Key Achievements
FUTURE DROUGHT (2020, 2050,2100)
CLIMATE-HYDROLOGY-DROUGHT MODELLING
van Lanen & Tallaksen (2009)
FP6 WATCH data andModelling scheme for drought assessment
Characteristics:- integrated models (coarse-scale)
- off-line approaches (more detailed)
. combined modeling and observations
. downscaling
. bias correction
. uncertainty propagation
. feed backs
Workshop Disaster Risk ReductionBrussels, 29-20 October 2009
Key Achievements
SPATIO-TEMPORAL CHARACTERIZATION
OF DIFFERENT TYPES OF DROUGHT (propagation)
van Lanen et al. (2009)
Space-time development of drought in the Danube Basin: precipitation (upper) and river flow (lower)
Workshop Disaster Risk ReductionBrussels, 29-20 October 2009
Key Challenges
FUTURE DROUGHTSCLIMATE-HYDROLOGY-DROUGHT
MODELLING
SHORT TERM: to advance knowledge on:
- off-line approaches
- generic approach that quantifies hydrological drought characteristics as a response to meteorological drough
- characterization of the spatio-temporal structure of drought (growth and decay) to assess likely
- space-time distribution of future large-scale drought (incl. synchronicity)
LONG TERM: to develop adequate Earth System Model
Workshop Disaster Risk ReductionBrussels, 29-20 October 2009
Key Achievements
DROUGHT MONITORING AND FORECASTING 2010 DROUGHT
Prec anamoly(NOAA)
Drought monitoring and Early Warning
Soil moisture anomaly (EDO-JRC)
Workshop Disaster Risk ReductionBrussels, 29-20 October 2009
Key Achievements
DROUGHT MONITORING AND FORECASTING 2010 DROUGHT
ECMWF anomalies:
� precipitation
� temperature 2m
� lead time 3 months (MJJ)
Drought forecasting (monthly and (multi-)seasonal
Workshop Disaster Risk ReductionBrussels, 29-20 October 2009
Key Achievements
DROUGHT MONITORING AND FORECASTING
Schaake (2006)
climate and hydrological ensembles forecasting system (EFS)
01.08.04 � 01.12.04
DROUGHT ?
Workshop Disaster Risk ReductionBrussels, 29-20 October 2009
Key Challenges
Significantly improve probabilistic forecasting
for (multi-)seasonal droughts in Europe
- taking better into account land-atmosphere feedbacks (vegetation, soil moisture and snow);
- ensemble-based probability information through multiple forecast models and multiple hydrologic models;
- link between droughts, weather types, sea surface temperature patterns and teleconnection patterns (e.g. NAO).
DROUGHT MONITORING AND FORECASTING
Workshop Disaster Risk ReductionBrussels, 29-20 October 2009
Drought impacts
Droughts are exogenous supply shocks with far-reachi ng ripple effects
Mysiak (2009)
physical
environmental
economic
social
Workshop Disaster Risk ReductionBrussels, 29-20 October 2009
Drought economic costs
Adams et al. (2002)
Australia1.6% of GDP decline, 1% of unemploy-ment
2002
Howitt et al. (2009)
California, US 80,000 jobs2.22009
RBA (2006)US20% farm GDP, <1% of GDP
2006
Hayes et al (2004)
US> 132002
Riebsame et al. (1991)
US39.41988
Ross and Lott (2003)
10 drought events in U.S
1 - 60 1980 - 2003
Billion US $
SourceDescriptionEstimated costs Drought
Workshop Disaster Risk ReductionBrussels, 29-20 October 2009
Drought
Drought has severe impacts on the environment, economy and society
Some key figures for Europe:
� in 2003 more than 100 million people and a third of the EU territory was affected;
� the cost to the European economy was at least €8.7 billion;� over the past thirty years, droughts have dramatically increased
in number and intensity in the EU and the cost in this period amounts to € 100 billion;
� Climate change is expected to make matters worse
Workshop Disaster Risk ReductionBrussels, 29-20 October 2009
Drought impacts
Direct costs Higher order effects+
tangible(but difficult to trace)
Vulnerability & Resilience? ?
difficult because of
data gaps, multiple costing methods and conceptualisations of losses
intangible(and oftenunobserved)
attribution of observed effects (responses to multiple stressors) to drought
Workshop Disaster Risk ReductionBrussels, 29-20 October 2009
Drought
CONCLUSIONS:
� close links with forest fires and heat waves (multi-h azard);
� severe environmental and socio-economic impacts;
� challenges (physical system, impact assessment, drou ght management are waiting for us (global change)
Workshop Disaster Risk ReductionBrussels, 29-20 October 2009
Drought
THANK YOU !
http://typo38.unesco.org/
European Drought Centre: http://www.geo.uio.no/edc
EC-IP WATCH: WATer and global Change: http://eu-watch.org/
EC-CSA XEROCHORE: An Exercise to Assess Research Needs and Policy Choices in Areas of Drought
