Current and future irrigation water requirements in pan-Europe: An integrated analysis of socio-economic and climate scenarios

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Irrigated cropland plays a crucial role for agricultural production but has also been identified as a major user of global freshwater resources. The amount of irrigation water needed depends on climate conditions and socio-economic factors (e.g. amount of crop production and technology). In this study we analyze the development of irrigated area and the corresponding net irrigation water requirements for pan-Europe using a spatially explicit land-use model (LandSHIFT) together with a hydrology and water-use model (WaterGAP3). Four simulation experiments for the assessment of irrigation water requirements were conducted: (1) irrigated area for the base year 2000 under climate normal conditions, (2) irrigated area for 2000 with two climate scenarios for 2050, (3) two scenarios for changing irrigated area until 2050 under climate normal conditions and (4) the two irrigated area scenarios in combination with the climate scenarios. Results show that under baseline conditions yearly irrigation water requirements sum up to 53billion m3. The expansion of irrigated area strongly depends on the combination of socio-economic drivers and climate change. Generally, the two analyzed climate scenarios lead to an expansion of irrigated area which we explain by negative effects of increasing air temperatures on crop growth conditions. Analysing the irrigated area scenarios and climate scenarios separately, we find that the effect of land-use change on net irrigation water requirements is larger than the climate effect. Combined analysis of socio-economic and climate drivers reveal that the expansion of irrigated area is not directly correlated to the changes of irrigation water requirements as the adaptation of sowing dates to the changing climatic conditions might help to overcome seasonal water deficits. The study underlines the importance of considering both the change of irrigated area and agricultural management as well as hydrology aspects in regional water use analysis and shows that simulation models can serve as tools to provide this information to the development of regional water management strategies.