Assessment of drought in the Mediterranean region under different climate change scenarios

Drought is one of the natural disasters with the widest range of impacts and it is essential to study its effects on ecosystems. In this study, future projections of monthly average temperature and monthly total precipitation data in the Mediterranean region of Turkey, which is an important region of the Eastern Mediterranean basin, with a multi-model ensemble created from 22 different global circulation models published within the scope of the 6th phase of the Coupled Model Intercomparison Project, were carried out using artificial neural networks-based statistical downscaling method. These projections were made using two different scenarios, SSP2-4.5 and SSP5-8.5 outputs for 2021-2100. Using the projection data, drought occurrence as a result of precipitation and temperature changes was examined by Standardized Precipitation Index and Standardized Precipitation Evapotranspiration Index methods. The study was conducted for the reference period 1979-2020 and for two different periods: near future (2021-2060) and far future (2061-2100). The results indicate a 15% decrease in precipitation in the region according to the SSP2-4.5 scenario and a 20% decrease according to the SSP5-8.5 scenario. In particular, it is observed that the decrease in precipitation in the coastal part of the region is higher than in other regions. This decrease in precipitation is more pronounced in the winter and fall seasons compared to other periods. In terms of temperature changes, an increase between +1.0 and +2.2 °C is expected in the SSP2-4.5 scenario compared to the historical period, while an increase between +1.8 and +3.1 °C is predicted in the SSP5-8.5 scenario. Drought index values calculated using past and future precipitation and temperature data were analyzed and it was determined that the increases in drought frequency in the mountainous regions of the study region will be more pronounced than in the coastal regions. The drought index values obtained in the study were evaluated temporally and spatially.