Irrigation water requirement (CLIM 033) - Assessment published Nov 2012
- In the Iberian Peninsula and Italy, an increase in the volume of water required for irrigation from 1975 to 2010 has been estimated, whereas parts of south-eastern Europe have recorded a decrease.
- The projected increases in temperature will lead to increased evapotranspiration rates, thereby increasing crop water requirements across Europe.
- The impact of increasing water requirements is expected to be most acute in southern Europe, where the suitability for rain-fed agriculture is projected to decrease and irrigation requirements are projected to increase.
How is climate change affecting the water requirement of agricultural crops and water availability for irrigation across Europe?
Rate of change of the meteorological water balance
Note: This figure shows the rate of change of the ‘water balance’. The map provides an estimate increase (red in map) or decrease (blue in map) of the volume of water required from irrigation assuming that all other factors are unchanged and given that there is an irrigation demand.
- Rate of change of frost-free period map for Europe provided by Geo network - open source
Projected change in water availability for irrigation in the Mediterranean region
Note: This figure shows the relative change in water availability for irrigation as projected under the A1B emission scenario by the HIRHAM (DMI) regional climate model for 2071-2100 relative to 1961-1990. Light yellow areas indicate no change in water availability.
- Regional Assessment of Climate Change in the Mediterranean provided by Euro-Mediterranean Centre on Climate Change (CMMC)
Consistent observations of water demand for agriculture do not currently exist for Europe but past trends can be estimated on the basis of meteorological data. Figure 1 estimates the change in the water balance, which is the difference between a reference evapotranspiration and the rainfall. This indicator provides only a rough proxy for changes in irrigation demand, because actual irrigation demand is determined by the crops grown, the type of irrigation applied and the local soil conditions. In the period considered (1975–2010), the Iberian Peninsula and Italy experienced an increase in the volume of water required for irrigation, if yields of irrigated crops were to be maintained, whereas parts of south-eastern Europe have experienced a decrease.
No projections of changes in irrigation demand are available for Europe. Many climate change projections show a consistent increase in the number of dry days in spring and summer in much of southern and central Europe [i]. In some of the severe climate change scenarios the increase in the number of dry days in summer even extends far into northern Europe. The increasing temperatures will increase the evaporative demand, which would be further increased if the higher frequency of dry days leads to lower relative humidity and reduced cloud cover. These effects will only be partly compensated by the reduced crop transpiration under higher CO2 concentrations [ii].
The expected increasing evapotranspiration will put pressure on the use of irrigation in drought-prone areas. Irrigation in Europe is currently concentrated along the Mediterranean, where some countries use more than 80 % of total freshwater abstraction for agricultural purposes [iii]. The increasing demand for irrigation will therefore increase the competition for water, in particular where total water availability declines due to reduced precipitation. Assuming that urban water demands would have preference over agricultural purposes, the proportional reduction of water availability for irrigation in many European basins is larger than the reduction in annual run-off (Figure 2) [iv]. Projections for the Mediterranean region show a considerable decline in water availability, which in some areas makes current irrigation practices impossible in the future.
[i] M. Trnka et al., „Agroclimatic Conditions in Europe Under Climate Change“, Global Change Biology 17, Nr. 7 (Juli 1, 2011): 2298–2318, doi:10.1111/j.1365-2486.2011.02396.x.
[ii] J. E. Olesen et al., „Uncertainties in projected impacts of climate change on European agriculture and terrestrial ecosystems based on scenarios from regional climate models“, Climatic Change 81 (März 17, 2007): 123–143, doi:10.1007/s10584-006-9216-1.
[iii] EEA, Water resources across Europe — confronting water scarcity and drought EEA Report (Copenhagen: European Environment Agency, 2009), http://www.eea.europa.eu/publications/water-resources-across-europe.
[iv] A. Iglesias et al., „Water and people: Assessing policy priorities for climate change adaptation in the Mediterranean“, in Regional Assessment of Climate Change in the Mediterranean (RACCM) (Springer, 2012), in press.
Indicator specification and metadata
- Rate of change of the meteorological water balance
- Projected change in water availability for irrigation in the Mediterranean region
- Meteorological water balance (m3/ha/yr)
- Change in water availability (%)
Policy context and targets
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.
No targets have been specified.
Related policy documents
Climate-ADAPT: Mainstreaming adaptation in EU sector policies
Overview of EU sector policies in which mainstreaming of adaptation to climate change is ongoing or explored
Climate-ADAPT: National adaptation strategies
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 later. This webportal 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 will enhance the preparedness and capacity of all governance levels to respond to the impacts of climate change.
Methodology for indicator calculation
The indicator has been produced querying a database, internal to Joint Research Centre (JRC), containing meteo data at 25 kilometers grid level, interpolated from meteo station data. The interpolation is performed taking into account only arable land, potentially suitable for crop growth. The meteo data are provided to JRC in the frame of the MARSOP 3 contract, complying with Council Regulation (EC) No 78/2008 of 21 January 2008 on the measures to be undertaken by the Commission in 2008-2013 making use of the remote-sensing applications developed within the framework of the common agricultural policy, Official Journal of the European Union, L 25 of 30 January 2008, p. 1.
The relative change in water availability for irrigation was projected under the A1B emission scenario by the HIRHAM (DMI) regional climate model for 2071-2100 relative to 1961-1990, using the WAPAA model for water availability under policy and climate change scenarios.
Methodology for gap filling
No methodology references available.
Data sets uncertainty
Effects of climate change on the growing season and crop phenology can be monitored directly, partly through remote sensing (growing season) and partly through monitoring of specific phenological events such as flowering. There is no common monitoring network for crop phenology in Europe, and data on this therefore has to be based on various national recordings, often from agronomic experiments. Crop yield and crop requirements for irrigation are not only affected by climate change, but also by management and a range of socio-economic factors. The effects of climate change on these factors therefore have to be estimated indirectly using agrometeorological indicators and through statistical analyses between climatic variables and factors such as crop yield.
The projections of climate change impacts and adaptation in agriculture rely heavily on modelling, and it needs to be recognised that there is often a chain of uncertainty involved in the projections going from emission scenario, through climate modelling, downscaling and to assessments of impacts using an impact model. The extent of all these uncertainties is rarely quantified, even though some studies have assessed uncertainties related to individual components. The crop modelling community has only recently started addressing uncertainties related to modelling impacts of climate change on crop yield and effect of possible adaptation options, and so far only few studies have involved livestock systems. Future studies also need to better incorporate effects of extreme climate events as well as biotic hazards (e.g. pests and diseases).
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/)
No uncertainty has been specified
Regional Assessment of Climate Change in the Mediterranean
provided by Euro-Mediterranean Centre on Climate Change (CMMC)
Monitoring Agricultural ResourceS (MARS)
provided by Joint Research Centre (JRC)
Climate change (Primary topic)
Typology: Descriptive indicator (Type A - What is happening to the environment and to humans?)
- CLIM 033
Contacts and ownership
EEA Contact InfoHans-Martin Füssel
EEA Management Plan2012 2.0.1 (note: EEA internal system)
Frequency of updates
For references, please go to www.eea.europa.eu/soer or scan the QR code.
This briefing is part of the EEA's report The European Environment - State and Outlook 2015. The EEA is an official agency of the EU, tasked with providing information on Europe’s environment.
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