From past to future: Spatiotemporal insights into drought stress on Belgian pome fruit production for 1991–2090

Recurring drought episodes cause significant economic losses and uncertainty in the Belgian pome fruit sector, requiring effective risk management strategies. Considering the expected increase in frequency, intensity and duration of drought episodes, our study focuses on quantifying the associated location-specific hazard for apple and pear orchards in Belgium. A spatially distributed implementation of the growth model AquaCrop was used to calculate a daily soil water balance at a 12.5 × 12.5 km spatial resolution based on nine bias corrected regional climate model projections from the EURO-CORDEX ensemble for emission scenarios RCP4.5 and RCP8.5. The spatiotemporal evolution of the precipitation deficit (mm), transpiration deficit (mm) and net irrigation requirement (mm) were used to assess current and future meteorological and agricultural drought hazards. We find a spatially averaged increase of the transpiration deficit of 61.4% (39.0%) and the net irrigation requirement of 32.3 % (18.5%) comparing a period in the far future (2061–2090) to a baseline period (1991–2020) under scenario RCP8.5 (RCP4.5). In addition, corresponding interquartile ranges of 204.2% (77.6%) and 30.8% (10.3%) show a large inter-climate model variability in the simulation results. The projected increase of the precipitation deficit during the summer months causes agricultural drought in a spatially heterogeneous manner, relating to the soil total available water content and depth to the shallow groundwater table. Despite the overall increase in drought hazard, the suitability of the current production regions is not projected to change relative to other agricultural regions in Belgium regarding agricultural drought. • Drought hazards for pome fruit production in Belgium will increase in the future. • Agricultural drought is more spatially variable than meteorological drought. • Drought-prone soils in areas most exposed to drought amplify this effect. • No large shifts in optimal growing regions occur regarding future drought hazards.