DATE2022-05-25 11:51:22
TITLEInvestigation of SPI and SPEI trends for wet and dry periods under climate change in Greece
AUTHORSNadia Politi (1,2) ,Diamando Vlachogiannis (1) ,Athanasios Sfetsos (1) ,Panagiotis T. Nastos (2)
  1. 1) Nscr Demokritos, Agia Paraskseui (Greece) ,2) Department Of Geology And Geoenvironment, Athens (Greece)
ABSTRACTAccording to IPCC 2021, droughts have become more frequent and intense, especially in the North Mediterranean, under moderate emission scenarios, and strongly enhanced under severe emission scenarios. Accordingly, Greece will face relatively severe drought conditions in the upcoming years. The present study investigates drought projected trends during wet and dry season over Greece based on the high-resolution output dataset of the Weather Research and Forecasting (WRF) model at 5-km grid spacing. WRF was driven by EC-EARTH-GCM output in the domain of Greece at very high resolution for the historical and future periods under two Representative Concentration Pathways 4.5 (RCP4.5) and 8.5 (RCP8.5). The standardized precipitation evapotranspiration index (SPI) and standardized precipitation evapotranspiration index (SPEI) data were calculated for an accumulation period of 6-months timescale for selected cities. This timescale distinction is according to the definition of the Hellenic National Meteorological Service (HNMS), as precipitation occurs in Greece during the wet season from October to March, while the dry season lasts from April to September with scarce intervals of rapid rain or thunderstorms of small duration mainly in mainland areas. Overall, the projected results using both indices showed both positive and negative trends, pointing out that a strong positive trend of severe drought events is expected, mainly under RCP8.5.