Exploring the aridity risk in agricultural lands of southwest Spain: the Extremadura region

Agricultural lands are essential for sustaining rural economies in economically lagging regions, but remain highly vulnerable to climate variability and aridification. In southwestern Spain, especially Extremadura, detailed assessments about this topic remain limited. This study quantified temporal and spatial climate variations in irrigated and rainfed areas using high-resolution gridded datasets and meteorological records from CMIP6 projections. Four future periods (2021–2100) under the SSP2-4.5 and SSP5-8.5 scenarios were compared with a historical baseline (1970–2000) through hydroclimatic indicators including precipitation and temperature anomalies, aridity indices, and the Budyko framework. Projections showed a precipitation decline in both irrigated and rainfed areas (up to −20% in SSP5-8.5 by 2081–2100, with local decreases exceeding 200 mm in irrigated areas with complex topography). Mean temperatures increased similarly in both agricultural systems by ≈6 °C. The aridity index showed that irrigated lands changed from predominantly Mediterranean to semi-arid and arid, with more than 80% classified as arid by the late century under SSP5-8.5, whereas rainfed lands changed by 60% to arid conditions. Budyko-based analysis indicated decreasing runoff generation as increasing potential evapotranspiration exceeded precipitation. These findings confirm a strong aridification trend, emphasizing the urgent need for adaptive water management, resilient cropping systems, and climate-informed agricultural policies.