Future Changes in Drought Characteristics over the Iberian Peninsula

Drought phenomena are already considered as one of the most devastating natural hazards nowadays, causing tremendous impacts on humans and ecosystems every year. In a warmer world, drought severity is expected to increase, making of high relevance the study of the impact of this phenomenon at a regional scale. This study aims to explore meteorological drought projections for the Iberian Peninsula (IP), a Mediterranean region where the effects of climate change are expected to be severe by the end of the 21st century. To achieve this, regional climate simulations were completed using the Weather Research and Forecasting (WRF) model driven by two global climate models (GCMs) from the phase 5 Coupled Model Intercomparison Project (CMIP5), the MPI- ESM-LR and the CCSM4, both under the representative concentration pathway (RCP) scenario RCP8.5. Future drought conditions were examined for two time slices, the near (2021-2050) and the far (2071-2100) futures with respect to the recent past (1980-2014). The study focused on drought characteristics (duration, frequency, and intensity) using two drought indicators, the Standardized Precipitation Index (SPI) and the Standardized Precipitation Evapotranspiration Index (SPEI) at 3- and 12-month timescales. In general, results suggest that the IP could undergo substantial changes in its drought conditions in the future. These changes, in particular, could become significant by the end of the century when noticeable increases in drought duration relative to the baseline period have been found in most of the IP, particularly for the SPEI at the 12-month timescale.