Climate Change Projections of Agricultural Droughts in Europe: A Comparison between Standardized Drought Indices

Drought is one of the most devastating natural hazards, affecting ecosystems, communities, and their economies worldwide. According to the last IPCC report, is expected, indeed, an increase in severity and frequency of drought under a changing climate, at least over Mediterranean regions. However, is still more uncertain the effect of climate change in other regions in the world.

To analyze the effect of this extreme phenomenon, many drought indices have been developed in recent years based on different hydroclimatic variables and depending on the type of drought under study. Among these indices it is worth mentioning, for meteorological droughts, the Standardized Precipitation Index (SPI) or the Standardized Precipitation Evapotranspiration Index (SPEI), agricultural drought indices such as the Standardized Soil moisture Index (SSI), or those that make use of different variables or multivariate indices such as the Multivariate Standardized Drought Index (MSDI) that combines soil moisture and precipitation, and the Standardized Precipitation Evapotranspiration Soil Moisture Index (SPESMI), an adaptation of the MSDI that incorporates the effect of potential evapotranspiration on the water balance.

This work aims to analyze from meteorological to agricultural droughts projections over Europe using standardized drought indices. For this, we evaluate drought characteristics (i.e., duration and intensity of drought events) for the different drought indicator at scales from 1 to 48 months using an ensemble of climate change regional projections from EURO-CORDEX under a business-as-usual climate change scenario. Changes for the future were analyzed for global warming corresponding to 1.5º, 2º, 3º and 4ºC of temperature above pre-industrial levels. The results of this analysis could offer useful information for adaptation strategies to climate change.

Keywords: standardized drought indices, agricultural droughts, Europe, climate change. projections.

Acknowledgments: This research was financed by the project P20_00035 funded by FEDER/Junta de Andalucía-Consejería de Transformación Económica, Industria, Conocimiento y Universidades, the project “Thematic Center on Mountain Ecosystem & Remote sensing, Deep learning-AIe-Services University of Granada-SierraNevada”(LifeWatch-2019-10-UGR-01), which has been co-funded by the Ministry of Science and Innovation through the FEDER funds from the Spanish Pluriregional Operational Program2014-2020 (POPE), LifeWatch-ERIC action line, and by the project PID2021-126401OB-I00 funded by MCIN/AEI/ 10.13039/501100011033/FEDER Una manera de hacer Europa.