Irrigation water requirement
- Model-based estimates suggest that the volume of water required for irrigation during the period from 1975 to 2010 has increased in the Iberian Peninsula and Italy whereas it has decreased in parts of south-eastern Europe.
- For high emissions scenarios, increases in irrigation demand of more than 25% during the 21st century are projected for most irrigated regions in 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 most.
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)
Irrigation in Europe is currently concentrated along the Mediterranean where some countries use more than 80 % of total freshwater abstraction for agricultural purposes[i]. However, consistent observations of water demand and consumption for agriculture do not currently exist for Europe, partly due to unrecorded water abstractions and to national differences in accounting and reporting. Modelling approaches can be used to compute net irrigation requirements. Two studies estimated net irrigation requirements in Europe for 1995-2002 and for the year 2000 with a total of three different model systems[ii]. The results show an irrigation requirement of up to 21-40 km3 for Spain, which has the highest net irrigation requirement in the EU27. Net irrigation requirements per area in Europe generally increase from North to South, determined by climatic conditions, soil properties and crop composition.
Past trends in water demand can be estimated on the basis of meteorological data. Figure 1 shows the change in the water balance, which is the difference between rainfall and modelled reference evapotranspiration, which is not crop-specific. This indicator provides a rough proxy for changes in actual irrigation demand, which is determined also by local soil conditions, the crops grown, and the type of irrigation applied. In the period considered (1975–2010), both the Iberian Peninsula and Italy have 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.
A recent multi-model study using seven global hydrological models driven by five global climate models under four representative concentration pathways (RCPs) estimated changes in irrigation water demand (IWD) across regions during the 21st century. Under the low and low-medium emissions scenarios RCP2.6 and RCP4.5, simulated changes in IWD across Europe are small. For RCP6.0, the multi-model average suggests a substantial increase in IWD in most of Europe. For RCP8.5, the projected increase in IWD exceeds 25% in most of the irrigated regions in Europe[iii]. Most hydrological models in this multi-model study did not consider the physiological effect of increased CO2, which can increase the water use efficiency of crop plants. The only available study using a hydrological and crop model that considers the physiological effect of increased CO2 still estimates that IWD in southern Europe increases by more than 20% until 2080 with a high likelihood[iv]. Regional case studies suggest much higher increases in IWD in some regions[v].
Changes in climate and CO2 are not the only factors affecting future IWD. Other important factors include changes in population, dietary preferences and food demand, land-use change and water-use policies. An integrated analysis of two socio-economic scenarios and one climate scenario (SRES A2) for pan-Europe showed almost no changes in IWD under a sustainability-oriented socio-economic scenario, whereas the combination of climate change with a market-oriented scenario lead to an increase in IWD of 45% [vi].
Climate change will also affect water availability. The Mediterranean area is projected to experience a decline in water availability, and future irrigation will be constrained by reduced runoff and groundwater resources, demand from other sectors, and by economic costs[vii]. 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)[viii].
Adaptation measures and integrated management of water, also across countries’ boundaries, are needed to address future competing demands for water between agriculture, energy, conservation and human settlements. New irrigation infrastructure will be required in some regions[ix].
[i] 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.
[ii] Gunter Wriedt et al., ‘Estimating Irrigation Water Requirements in Europe’,Journal of Hydrology 373, no. 3–4 (15 July 2009): 527–44, doi:10.1016/j.jhydrol.2009.05.018; T. aus der Beek et al., ‘Modelling Historical and Current Irrigation Water Demand on the Continental Scale: Europe’,Adv. Geosci. 27 (7 September 2010): 79–85, doi:10.5194/adgeo-27-79-2010.
[iii] Yoshihide Wada et al., ‘Multimodel Projections and Uncertainties of Irrigation Water Demand under Climate Change’,Geophysical Research Letters 40, no. 17 (16 September 2013): 4626–32, doi:10.1002/grl.50686.
[iv] Markus Konzmann, Dieter Gerten, and Jens Heinke, ‘Climate Impacts on Global Irrigation Requirements under 19 GCMs, Simulated with a Vegetation and Hydrology Model’,Hydrological Sciences Journal 58, no. 1 (2013): 88–105, doi:10.1080/02626667.2013.746495.
[v] R. Savé et al., ‘Potential Changes in Irrigation Requirements and Phenology of Maize, Apple Trees and Alfalfa under Global Change Conditions in Fluvià Watershed during XXIst Century: Results from a Modeling Approximation to Watershed-Level Water Balance’,Agricultural Water Management 114 (November 2012): 78–87, doi:10.1016/j.agwat.2012.07.006.
[vi] Rüdiger Schaldach et al., ‘Current and Future Irrigation Water Requirements in Pan-Europe: An Integrated Analysis of Socio-Economic and Climate Scenarios’,Global and Planetary Change 94–95 (August 2012): 33–45, doi:10.1016/j.gloplacha.2012.06.004.
[vii] J.E. Olesen et al., ‘Impacts and Adaptation of European Crop Production Systems to Climate Change’,European Journal of Agronomy 34, no. 2 (February 2011): 96–112, doi:10.1016/j.eja.2010.11.003.
[viii] Ana Iglesias et al., ‘Water and People: Assessing Policy Priorities for Climate Change Adaptation in the Mediterranean’, inRegional Assessment of Climate Change in the Mediterranean, ed. Antonio Navarra and Laurence Tubiana, Advances in Global Change Research 51 (Springer Netherlands, 2013), 201–33, http://link.springer.com/chapter/10.1007/978-94-007-5772-1_11.
[ix] Marijn van der Velde, Gunter Wriedt, and Fayçal Bouraoui, ‘Estimating Irrigation Use and Effects on Maize Yield during the 2003 Heatwave in France’,Agriculture, Ecosystems & Environment 135, no. 1–2 (1 January 2010): 90–97, doi:10.1016/j.agee.2009.08.017.
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 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 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 Plan2014 1.4.1 (note: EEA internal system)
Frequency of updates
For references, please go to http://www.eea.europa.eu/data-and-maps/indicators/water-requirement-1/assessment-1 or scan the QR code.
PDF generated on 04 Dec 2016, 07:26 AM