Crop Water Use and Future Irrigation Scenarios within a Safe Operating Space Framework in the Danube Basin

The Danube River Basin, spanning 19 countries and covering approximately 801,000 km², is an important agricultural region in Europe and exhibits strong spatial contrasts in water availability and use. Crop production in the basin depends on both rainfed and irrigated agriculture, with pronounced spatial diversity in crop composition, climate conditions, and water availability. Irrigation plays a critical role particularly in downstream areas, with many countries having plans or incentives to expand irrigated agriculture due to increasing drought risk under climate change. At the same time, increasing irrigation water demands may exacerbate water scarcity, alter river flow regimes, and intensify pressures on aquatic ecosystems, highlighting the need for a coordinated, basin-wide and adaptive future agricultural water management.

Building on the concept of Safe Operating Space (SOS), which aims to define sustainable limits for human pressures on Earth system processes, the Horizon Europe SOS-Water project seeks to operationalize the SOS for water resources under changing climatic and societal conditions. Within SOS-Water, agricultural water use is a key component of the coupled human–water system and is analysed using integrated modeling and stakeholders-informed future scenarios.

This proposed talk will present the application of the SOS framework in the Danube Basin, with a focus on spatially explicit crop modelling and future irrigation scenarios. Using the Community Water Model (CWatM), we simulate crop-specific water demands, seasonal dynamics, and irrigation scenarios consistent with Shared Socio-economic Pathways (SSP1-2.6, SSP3-7.0, SSP5-8.5), allowing the evaluation of irrigation expansion and efficiency improvements across the upper, middle, and lower Danube sub-basins.

The analysis will explore how crop dynamics and alternative irrigation pathways influence water demand and water availability in the Danube basin, and illustrate how the SOS approach can be used to support the assessment of sustainable water management options in transboundary regions.