Susceptibility of Iberia to Extreme Precipitation and Aridity: A New High-Resolution Analysis over an Extended Historical Period

The susceptibility to precipitation extreme events (PEEs) and aridity in the Iberian Peninsula (IP) were assessed over a long historical period (1950–2022). Eight extreme precipitation and two aridity indices were calculated. Furthermore, two newly developed composite and principal component-based susceptibility indices were applied. For this purpose, we applied a quantile mapping bias correction of the ERA5-Land reanalysis using the Iberia01 observational dataset in their overlapping period (1971–2015). A trend analysis for 1950–2022 revealed an annual and seasonal drying over the southwestern, central, and northeastern regions, accompanied by annual wetting over the southeast. The PEE contribution to the total precipitation, which was higher over the eastern IP (24 to 28%), increased in several coastal regions during winter, and in the north-central regions during summer and annually. High to very high susceptibility areas, corresponding to ~50% of the IP, were located on the mountains’ Atlantic/Mediterranean-facing side, whereas the inner plateaus revealed a low to moderate susceptibility. Apart from agreeing with previous studies, our results showed with high detail the susceptibility to PEEs and the recent past trends for all the IP regions, which is a novelty among similar studies and allows for improvements in e.g., crop management, urban planning, or risk mitigation.