River floods

Assessment versions

Published (reviewed and quality assured)

• No published assessments

Rationale

Justification for indicator selection

There are many different types of floods. They can be distinguished based on the source of flooding (e.g., rivers and lakes, urban storm water and combined sewage overflow, or sea water), the mechanism of flooding (e.g., natural exceedance, defence or infrastructural failure, or blockage) and other characteristics (e.g., flash flooding, snowmelt flood, or debris flow).

River floods are a common natural disaster in Europe, and — along with storms — the most important natural hazard in Europe in terms of economic damage. They are mainly caused by prolonged or heavy precipitation events or snowmelt. River floods can result in huge economic losses due to damage to infrastructure, property and agricultural land, and indirect losses in or beyond the flooded areas, such as production losses caused by damaged transport or energy infrastructure. They can also lead to loss of life, especially in the case of flash floods, and displacement of people, and can have adverse effects on human health, the environment and cultural heritage.

Scientific references

• . Barnolas, M., and M.C. Llasat. 2007. “A flood geodatabase and its climatological applications: the case of Catalonia for the last century.” Natural Hazards and Earth System Sciences 7 (2) (April 5): 271–281. doi:10.5194/nhess-7-271-2007. Barredo, J.I. 2009. “Normalised flood losses in Europe: 1970–2006.” Natural Hazards and Earth System Sciences 9 (February 9): 97–104. doi:10.5194/nhess-9-97-2009. Christensen, J. H, and Ole B. Christensen. 2002. “Severe summertime flooding in Europe.” Nature 421 (February 20): 805–806. Dankers, Rutger, and Luc Feyen. 2009. “Flood hazard in Europe in an ensemble of regional climate scenarios.” Journal of Geophysical Research 114 (D16) (August 27). doi:10.1029/2008JD011523. http://www.agu.org/pubs/crossref/2009/2008JD011523.shtml. Dartmouth Flood Observatory. 2012. “Global Active Archive of Large Flood Events”. Dartmouth Flood Observatory. http://floodobservatory.colorado.edu/index.html. EEA. 2009. Regional climate change and adaptation — The Alps facing the challenge of changing water resources. EEA Report. Copenhagen. http://www.eea.europa.eu/publications/alps-climate-change-and-adaptation-2009. ———. 2012. Urban Adaptation to Climate Change in Europe - Challenges and Opportunities for Cities Together with Supportive National and European Policies. EEA Report. Copenhagen: European Environment Agency. http://www.eea.europa.eu/publications/urban-adaptation-to-climate-change. EM-DAT. 2012. “The International Disaster Database, Centre for Research on Epidemiology of Disasters - CRED”. CRED. http://www.emdat.be. Feyen, Luc, Rutger Dankers, Katalin Bódis, Peter Salamon, and José I. Barredo. 2011. “Fluvial Flood Risk in Europe in Present and Future Climates.” Climatic Change 112 (1) (November 23): 47–62. doi:10.1007/s10584-011-0339-7. Flörke, Martina, Florian Wimmer, Cornelius Laaser, Rodrigo Vidaurre, Jenny Tröltzsch, Thomas Dworak, Natasha Marinova, et al. 2011. Climate Adaptation – modelling water scenarios and sectoral impacts. Final Report. Contract N° DG ENV.D.2/SER/2009/0034. Kassel, Germany: Center for Environmental Systems Research, University of Kassel. http://circa.europa.eu/Public/irc/env/wfd/library?l=/framework_directive/climate_adaptation/climwatadapt_report. Hannaford, Jamie, and Terry J Marsh. 2008. “High‐flow and Flood Trends in a Network of Undisturbed Catchments in the UK.” International Journal of Climatology 28 (10) (August 1): 1325–1338. doi:10.1002/joc.1643. Kundzewicz, Zbigniew W., Maciej Radziejewski, and Iwona Pínskwar. 2006. “Precipitation extremes in the changing climate of Europe.” Climate Research 31 (June 26): 51–58. doi:10.3354/cr031051. Pall, Pardeep, Tolu Aina, Dáithí A. Stone, Peter A. Stott, Toru Nozawa, Arno G. J. Hilberts, Dag Lohmann, and Myles R. Allen. 2011. “Anthropogenic Greenhouse Gas Contribution to Flood Risk in England and Wales in Autumn 2000.” Nature 470 (7334) (February 16): 382–385. doi:10.1038/nature09762. Petrow, Theresia, and Bruno Merz. 2009. “Trends in flood magnitude, frequency and seasonality in Germany in the period 1951–2002.” Journal of Hydrology 371 (1–4) (June 5): 129–141. doi:10.1016/j.jhydrol.2009.03.024. Renard, B., M. Lang, P. Bois, A. Dupeyrat, O. Mestre, H. Niel, E. Sauquet, et al. 2008. “Regional methods for trend detection: Assessing field significance and regional consistency.” Water Resources Research 44 (August 12): W08419. doi:10.1029/2007WR006268. Veijalainen, Noora, Eliisa Lotsari, Petteri Alho, Bertel Vehviläinen, and Jukka Käyhkö. 2010. “National Scale Assessment of Climate Change Impacts on Flooding in Finland.” Journal of Hydrology 391 (3–4) (September 24): 333–350. doi:10.1016/j.jhydrol.2010.07.035. Villarini, Gabriele, James A Smith, Francesco Serinaldi, Alexandros A Ntelekos, and Ulrich Schwarz. 2012. “Analyses of Extreme Flooding in Austria over the Period 1951–2006.” International Journal of Climatology 32 (8): 1178–1192. doi:10.1002/joc.2331. Wilson, Donna, Hege Hisdal, and Deborah Lawrence. 2010. “Has Streamflow Changed in the Nordic Countries? – Recent Trends and Comparisons to Hydrological Projections.” Journal of Hydrology 394 (3–4) (November 26): 334–346. doi:10.1016/j.jhydrol.2010.09.010.

Indicator definition

• Occurrence of major floods in Europe

• Projected change in river floods with a return period of 100 years

Units

• Number of events
• %

Policy context and targets

Context description

In April 2013 the European Commission presented the EU Adaptation Strategy Package (http://ec.europa.eu/clima/policies/adaptation/what/documentation_en.htm). This package consists of the EU Strategy on adaptation to climate change /* COM/2013/0216 final */ and a number of supporting documents. One of the objectives of the EU Adaptation Strategy is Better informed decision-making, which should occur through Bridging the knowledge gap and Further developing Climate-ADAPT as the ‘one-stop shop’ for adaptation information in Europe. Further objectives include Promoting action by Member States and Climate-proofing EU action: promoting adaptation in key vulnerable sectors. Many EU Member States have already taken action, such as by adopting national adaptation strategies, and several have also prepared action plans on climate change adaptation.

The European Commission and the European Environment Agency have developed the European Climate Adaptation Platform (Climate-ADAPT, http://climate-adapt.eea.europa.eu/) to share knowledge on observed and projected climate change and its impacts on environmental and social systems and on human health; on relevant research; on EU, national and subnational adaptation strategies and plans; and on adaptation case studies.

Targets

No targets have been specified.

Related policy documents

• Climate-ADAPT: Adaptation in EU policy sectors
  Overview of EU sector policies in which mainstreaming of adaptation to climate change is ongoing or explored
• Climate-ADAPT: Country profiles
  Overview of activities of EEA member countries in preparing, developing and implementing adaptation strategies
• DG CLIMA: Adaptation to climate change
  Adaptation means anticipating the adverse effects of climate change and taking appropriate action to prevent or minimise the damage they can cause, or taking advantage of opportunities that may arise. It has been shown that well planned, early adaptation action saves money and lives in the future. This web portal provides information on all adaptation activities of the European Commission.
• EU Adaptation Strategy Package
  In April 2013, the European Commission adopted an EU strategy on adaptation to climate change, which has been welcomed by the EU Member States. The strategy aims to make Europe more climate-resilient. By taking a coherent approach and providing for improved coordination, it enhances the preparedness and capacity of all governance levels to respond to the impacts of climate change.

Methodology

Methodology for indicator calculation

The occurrence of flood events in Europe from 1998–2009 is based on data of the Dartmouth Flood Observatory. This picture is incomplete because events with small spatial extent and/or impact are not included.

Projected change in the level of a 100-year maximum level of river discharge between the reference period 1961–1990 and the 2020s (left), 2050s (centre) and the 2080s (right) are based on an ensemble of 12 RCM simulations with LISFLOOD for the SRES A1B scenario.

Methodology for gap filling

Not applicable

Methodology references

• Rojas et al. 2012: Assessment of Future Flood Hazard in Europe Using a Large Ensemble of Bias Corrected Regional Climate Simulations. Rojas, R., Feyen, L., Bianchi, A. and Dosio, A. (2012) Assessment of Future Flood Hazard in Europe Using a Large Ensemble of Bias Corrected Regional Climate Simulations. Journal of Geophysical Research. doi:10.1029/2012JD017461

Data specifications

EEA data references

• No datasets have been specified here.

External data references

• River floods

Data sources in latest figures

Uncertainties

Methodology uncertainty

Not applicable

Data sets uncertainty

Detailed data on water quantity is often difficult to assess, and homogeneous time series are generally shorter than those for meteorological data. It may, therefore, require substantially more time before statistically significant changes in hydrological variables can be observed than for meteorological variables, especially with respect to extreme events (floods and droughts). Quantitative projections of changes in precipitation and river flows at the basin scale remain highly uncertain due to the limitations of climate models and to scaling issues between climate and hydrological models.

The main data sources for European-wide studies of extreme hydrological events and their changes are global databases for natural disasters. These include general impact-oriented disaster databases such as EM-DAT ([1]) maintained by the Centre for Research on the Epidemiology of Disasters (CRED) and the NatCatService ([2]) maintained by Munich Re, as well as specific mostly event-oriented databases, such as the Dartmouth Flood Observatory ([3]). Some of the limitations of these databases included the use of thresholds for inclusion of an event, which may exclude smaller events with a significant regional impact, changes over time in the comprehensiveness of the coverage (see below), and privacy issues related to detailed data collected by the insurance industry. Improvements of these datasets are planned in coming years. The available data is currently evaluated, for example in the ongoing emBRACE project ([4]). A more detailed and comprehensive event-oriented database that also includes events without any (major) damages would be needed to separate the effect of climate change from socio-economic changes.

The reporting of flood and drought events has generally improved during the past few decades as a result of improvements in data collection and flows of information. As a result, it is often difficult to identify whether an increase in reported flood events (or their impacts) over time is due mostly to improvements in data collection or to actual changes in these events. Furthermore, river flood records are usually sourced from different institutions and often collected using a wide range of different assessment methods and rationales, which may have changed over time. This multitude of sources limits the comparability of key attributes associated with such events (e.g. economic losses, human casualties) across space and time.

As part of the preliminary flood risk assessment for the European directive on the assessment and management of flood risks (2007/60/EC) ([5]), EU Member States will give an overview of significant past floods. In addition, a European flood impact database could bring together publicly available inventories of flood events. At the national/regional level, such an inventory would be particularly useful to provide accurate data and assessments which would serve as a basis for disaster prevention. At the European level, these inventories could assist in tracking the trends in flood-disaster losses, and in mitigation programmes monitoring and obtaining a clearer picture of the linkages between climate change and floods and flood losses.

Further information on uncertainties is provided in Section 1.7 of the EEA report on Climate change, impacts, and vulnerability in Europe 2012 (http://www.eea.europa.eu/publications/climate-impacts-and-vulnerability-2012/)

[1] See http://www.emdat.be online.

[2] See http://www.munichre.com/geo online.

[3] See http://floodobservatory.colorado.edu/ online.

[4] See http://embrace-eu.org/ online.

[5] See http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2007:288:0027:0034:EN:PDF online.

Rationale uncertainty

No uncertainty has been specified