Meteorological and hydrological droughts in Europe

Assessment versions

Published (reviewed and quality assured)

• No published assessments

Rationale

Justification for indicator selection

Droughts can have severe consequences for Europe’s ecosystems and citizens, and for many economic sectors, including agriculture, energy production, industry and public water supply. It is important to distinguish between different kinds of drought. A persistent meteorological drought (i.e. a precipitation deficiency) can propagate to a soil moisture (agricultural) drought affecting plant and crop growth, which may deepen into a hydrological drought affecting water resources, water quality and freshwater ecosystems.

This indicator comprises two types of drought: meteorological and hydrological droughts, with the latter focusing on river flow droughts. A meteorological drought is defined in terms of precipitation deficiency, which may be exacerbated by high temperature associated with high evapotranspiration. Meteorological droughts are usually characterised using statistical indices, such as the Standardised Precipitation Index (SPI), Standardised Precipitation Evapotranspiration Index (SPEI) and Reconnaissance Drought Index (RDI). A river flow drought is characterised by unusually low river flow, which may result from a prolonged meteorological drought, possibly in combination with socio-economic factors.

Scientific references

• IPCC, 2013. Climate Change: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Stocker, T. F., D. Qin, G.-K. Plattner, M. Tignor, S. K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex and P. M. Midgley (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 1535 pp.
• IPCC, 2014: Europe. Kovats, R.S., R. Valentini, L.M. Bouwer, E. Georgopoulou, D. Jacob, E. Martin, M. Rounsevell, and J.-F. Soussana, 2014: Europe. In: Climate Change 2014: Impacts, Adaptation, and Vulnerability. Part B: Regional Aspects. Contribution of Working Group II to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Barros, V.R., C.B. Field, D.J. Dokken, M.D. Mastrandrea, K.J. Mach, T.E. Bilir, M. Chatterjee, K.L. Ebi, Y.O. Estrada, R.C. Genova, B. Girma, E.S. Kissel, A.N. Levy, S. MacCracken, P.R. Mastrandrea, and L.L. White (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, pp. 1267-1326.

Indicator definition

• Observed trend in the frequency of meteorological droughts
• Observed trend in runoff during the driest month
• Projected change in the frequency of meteorological droughts
• Projected change in 10-year river water deficit due to climate change

Units

• Trend in events per decade
• Percentage change (%) per decade
• Change in events per decade
• Percentage change (%)

Policy context and targets

Context description

In April 2013, the European Commission (EC) presented the EU Adaptation Strategy Package. This package consists of the EU Strategy on adaptation to climate change (COM/2013/216 final) and a number of supporting documents. The overall aim of the EU Adaptation Strategy is to contribute to a more climate-resilient Europe. One of the objectives of the EU Adaptation Strategy is Better informed decision-making. This shall be achieved by bridging the knowledge gap and further developing the European climate adaptation platform (Climate-ADAPT) as the ‘first-stop shop’ for adaptation information in Europe. Climate-ADAPT has been developed jointly by the EC and the EEA to share knowledge on (1) observed and projected climate change and its impacts on environmental and social systems and on human health, (2) relevant research, (3) EU, transnational, national and subnational adaptation strategies and plans, and (4) adaptation case studies. It was relaunched in early 2019 with a new design and updated content. Further objectives include Promoting adaptation in key vulnerable sectors through climate-proofing EU sector policies and Promoting action by Member States.

In November 2018, the Commission published its evaluation of the 2013 EU Adaptation Strategy. The evaluation package includes a Report from the Commission, a Commission Staff Working Document, the Adaptation preparedness scoreboard country fiches, and the reports from the JRC PESETA III project. This evaluation includes recommendations for the further development and implementation of adaptation policies at all levels.

In November 2013, the European Parliament and the European Council adopted the 7th EU Environment Action Programme (7th EAP) to 2020, ‘Living well, within the limits of our planet’. The 7th EAP is intended to help guide EU action on environment and climate change up to and beyond 2020. It highlights that ‘Action to mitigate and adapt to climate change will increase the resilience of the Union’s economy and society, while stimulating innovation and protecting the Union’s natural resources.’ Consequently, several priority objectives of the 7th EAP refer to climate change adaptation. In November 2013, the European Parliament and the European Council adopted the 7th EU Environment Action Programme (7th EAP) to 2020, ‘Living well, within the limits of our planet’. The 7th EAP is intended to help guide EU action on the environment and climate change up to and beyond 2020. It highlights that ‘Action to mitigate and adapt to climate change will increase the resilience of the Union’s economy and society, while stimulating innovation and protecting the Union’s natural resources.’ Consequently, several priority objectives of the 7th EAP refer to climate change adaptation.

Targets

No targets have been specified.

Related policy documents

• 7th Environment Action Programme
  DECISION No 1386/2013/EU OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 20 November 2013 on a General Union Environment Action Programme to 2020 ‘Living well, within the limits of our planet’. In November 2013, the European Parliament and the European Council adopted the 7 th EU Environment Action Programme to 2020 ‘Living well, within the limits of our planet’. This programme is intended to help guide EU action on the environment and climate change up to and beyond 2020 based on the following vision: ‘In 2050, we live well, within the planet’s ecological limits. Our prosperity and healthy environment stem from an innovative, circular economy where nothing is wasted and where natural resources are managed sustainably, and biodiversity is protected, valued and restored in ways that enhance our society’s resilience. Our low-carbon growth has long been decoupled from resource use, setting the pace for a safe and sustainable global society.’
• A Blueprint to Safeguard Europe's Water Resources
  COMMUNICATION FROM THE COMMISSION TO THE EUROPEAN PARLIAMENT, THE COUNCIL, THE EUROPEAN ECONOMIC AND SOCIAL COMMITTEE AND THE COMMITTEE OF THE REGIONS A Blueprint to Safeguard Europe's Water Resources /* COM/2012/0673 final */
• Addressing the challenge of water scarcity and droughts in the European Union
  EC (2007). Communication from the Commission to the Council and the European Parliament, Addressing the challenge of water scarcity and droughts in the European Union. Brussels, 18.07.07, COM(2007)414 final.
• 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.
• Directive 2000/60/EC of the European Parliament and of the Council establishing a framework for Community action in the field of water policy
  EC (2000). Directive 2000/60/EC of the European Parliament and of the Council establishing a framework for Community action in the field of water policy. OJ L327, 22.12.2000.
• 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.
• Evaluation of the EU Adaptation Strategy Package
  In November 2018, the EC published an evaluation of the EU Adaptation Strategy. The evaluation package comprises a Report on the implementation of the EU Strategy on adaptation to climate change (COM(2018)738), the Evaluation of the EU Strategy on adaptation to climate change (SWD(2018)461), and the Adaptation preparedness scoreboard Country fiches (SWD(2018)460). The evaluation found that the EU Adaptation Strategy has been a reference point to prepare Europe for the climate impacts to come, at all levels. It emphasized that EU policy must seek to create synergies between climate change adaptation, disaster risk reduction efforts and sustainable development to avoid future damage and provide for long-term economic and social welfare in Europe and in partner countries. The evaluation also suggests areas where more work needs to be done to prepare vulnerable regions and sectors.

Methodology

Methodology for indicator calculation

Meteorological droughts are based on the Standardised Precipitation Index for three months (SPI-3). Past trends are based on precipitation data from the E-OBS gridded dataset, whereas projections are based on a model ensemble from the EURO-CORDEX project for two emissions scenarios.

Trends in hydrological droughts are calculated based on the runoff during the driest month in the E-RUN dataset. The E-RUN dataset employed a statistical model to estimate runoff across Europe based on the largest database of streamflow observations and the E-OBS dataset. Hydrological drought projections are based on the 10-year river water deficit, as calculated by the LISFLOOD hydrological model forced by a model ensemble from the EURO-CORDEX project for two emissions scenarios.

Methodology for gap filling

Not applicable

Methodology references

• Spinoni, J., et al. (2017): Pan-European seasonal trends and recent changes of drought frequency and severity. Spinoni, J., et al., 2017, ‘Pan-European seasonal trends and recent changes of drought frequency and severity’, Global and Planetary Change148, pp. 113-130 (DOI: 10.1016/j.gloplacha.2016.11.013).
• Gudmundsson and Seneviratne (2016): Observation-based gridded runoff estimates for Europe (E-RUN version 1.1). Gudmundsson, L. and Seneviratne, S. I., 2016, ‘Observation-based gridded runoff estimates for Europe (E-RUN version 1.1)’,Earth System Science Data8(2), pp. 279-295 (DOI: 10.5194/essd-8-279-2016).
• Spinoni et al. (2018): Will drought events become more frequent and severe in Europe? Spinoni, J., et al., 2018, ‘Will drought events become more frequent and severe in Europe?’,International Journal of Climatology38(4), pp. 1718-1736 (DOI: 10.1002/joc.5291).
• Cammalleri et al. (in press): Global warming and drought impacts in the EU. Cammalleri, C., et al., in press, Global warming and drought impacts in the EU, EUR 29956 EN, Publications Office of the European Union, Luxembourg.

Data specifications

EEA data references

• No datasets have been specified here.

External data references

• Projections of future meteorological droughts in Europe
• Trend in annual meteorological drought frequency (copyright-protected)
• Observation-based gridded runoff estimates for Europe (E-RUN version 1.1)
• Projected change in extreme river water deficit volume (direct URL to the dataset is not available)

Data sources in latest figures

Uncertainties

Methodology uncertainty

See 'Methodology'.

Data sets uncertainty

The data required for the indicators in this sector are time series of precipitation (for meteorological droughts) and extreme low flows (for hydrological droughts), respectively. These time series can be observed or simulated for historical time periods and can be projected for future time windows, taking into account climate change and potentially also other drivers of change, such as land-use changes.

River flow data are influenced by rainfall run-off and by hydromorphological changes of the river bed, e.g. through river engineering. Homogeneous time series are generally shorter than those for meteorological data. Therefore, substantially more time may be required before statistically significant changes in hydrological variables can be observed, especially with respect to extreme events (floods and droughts). Notwithstanding recent improvements of climate models to simulate large-scale patterns of precipitation and extreme events, projections of changes in precipitation remain uncertain, especially at catchment and local scales.

Reliable information on the extent and impacts of water scarcity and droughts is indispensable for decision-making at all levels. The Joint Research Centre (JRC) of the European Commission has developed a European Drought Observatory (EDO) for drought forecasting, assessment and monitoring while the EEA regularly develops and updates the water scarcity indicator at basin and country level across Europe. However, despite several activities, there is no systematic, comprehensive record of water scarcity and drought events available in Europe.

Rationale uncertainty

No uncertainty has been specified