Understanding reference evapotranspiration distribution and evolution in the Northwestern Mediterranean basin

Drought episodes are among the most devasting natural disasters impacting agriculture, forests, the environment, and economic activity. Catalonia, in the Northwestern Mediterranean basin, is currently experiencing its most severe drought episode on record.
For a comprehensive examination of drought episodes, it is crucial to consider different processes involved in water balance. However, many studies tend to focus solely on precipitation scarcity, often overlooking other critical variables like evapotranspiration or approximating it through simplified methods.
While uncertainty persists regarding present and future precipitation patterns in the Mediterranean basin, the temperature is showing a steady increase and is projected to rise even more in the future. This rise could intensify evapotranspiration rates, exacerbating drought episodes. 
Nonetheless, it is essential to note that evapotranspiration is not only influenced by temperature; other meteorological variables such as solar radiation, relative humidity, and wind also play significant roles. 
This study aims to analyze the relative impact of different meteorological variables on evapotranspiration to better understand the factors affecting this relevant phenomenon for drought management in Catalonia. Such insights will provide valuable information for adapting to future droughts episodes.
The study proposes an  in-depth analysis of evapotranspiration in Catalonia, using data collected by the XEMA observation network of the Meteorological Service of Catalonia (SMC). This network extensively covers the region, providing data for calculating evapotranspiration on  monthly, daily, and even hourly time scales. Taking advantage of this dataset, the Penman-Monteith formulation is employed to compute reference crop evapotranspiration (ETo). The evolution of this variable in the territory, its spatial distribution, and case studies such as the recent 2020-2024 episode are studied.