Estimating irrigation water requirements in Europe

In Southern Europe, irrigated agriculture is by far the largest consumer of freshwater resources. However, consistent information on irrigation water use in the European Union is still lacking. We applied the crop growth model EPIC to calculate irrigation requirements in the EU and Switzerland, combining available regional statistics on crop distribution and crop specific irrigated area with spatial data sources on soils, land use and climate. The model was applied at a 10×10km grid using different irrigation strategies over a period of 8years. The irrigation requirements reflect the spatial distribution of irrigated areas, climatic conditions and crops. Simulated net irrigation requirements range from 53mm/yr in Denmark to 1120mm/yr in Spain, translating into estimated volumetric net irrigation requirements of 107mio.m3 and 35,919mio.m3, respectively. We estimate gross irrigation demands to be 1.3–2.5 times higher than field requirements, depending on the efficiency of transport and irrigation management. A comparison with national and regional data on water abstractions for irrigation illustrates the information deficit related to currently available reported data, as not only model limitations but also different national approaches, country-specific uncertainties (illegal or unrecorded abstractions), and restrictions of actual water use come into play. In support of European environmental and agricultural policies, this work provides a large-scale overview on irrigation water requirements in Europe applying a uniform approach with a sufficiently high spatial resolution to support identification of hot spots and regional comparisons. It will also provide a framework for national irrigation water use estimations and supports further analysis of agricultural pressures on water quantity in Europe.