Meteorological Drought Analysis at North-Western Ankara

This paper investigates a meteorological drought analysis at two meteorology stations near metropolitan city of Ankara, Turkey. The standardized precipitationevapotranspiration index (SPEI) were estimated at the reference period 1971–2000 and compared with those of the near future climate period (2016–2040) under RCP4.5 andRCP8.5 greenhouse gas scenarios. Historical simulations and projections of future changes on the drought indices at each station were derived using regional climate modelRegCM4.3.4 to obtain a series of high-resolution simulations of three global climate models (GCMs) used in the Coupled Model Intercomparison Project Phase 5 (CMIP5)experiments. A spatial adjustment between the grid points and meteorology stations was achieved by the grid-based pattern oriented linear scaling bias correction procedure. Ingeneral, the results pointed out that the stations experienced 11 and 4 extreme drought cases respectively at Beypazari and Nallihan stations during the reference period.However, the projections under the RCP4.5 and RCP8.5 scenarios respectively indicated 0 and 13 extreme drought events at the near future at both stations. While the RCP 4.5scenario showed that dry spells were dominant in the second half of the near future period, the RCP 8.5 projected dry spells evenly distributed during the entire near futureperiod.