ATMOS 2019, İstanbul, Türkiye, 23 Ekim 2019, ss.213-221
Drought Analysis using CORDEX Simulations over the Mediterranean Climate Regions
of Turkey
Anil Poyraz and Ismail Yucel
Middle East Technical University
Engineering Faculty, Civil Engineering Department, Water Resource Lab. anil.poyraz@metu.edu.tr, iyucel@metu.edu.tr
ABSTRACT
Mediterranean region is one of the hotspots of the world in this respect to impacts of climate change. Dry summers and rainy winters -the characteristic of this climate type- makes this region more
vulnerable in this sense. This study aims to assess the trends in drought in Mediterranean climate
region of Turkey by applying the Standardized Precipitation Index (SPI) for 5 timescales – from 1
month to 12 months. The model grid data that corresponds to meteorological stations distributed from
south to west within the study area was obtained from 12 different Global Circulation Model /
Regional Climate Model couplings of CORDEX project. Observed and model data were compared for
reference period (1971-2005) to detect the models that show better agreement with the observations. Afterwards, modified Mann-Kendall trend test was applied on the SPI values for the entire period
(1972-2100). The trends were estimated by linear regression for the locations on which Mann-Kendall
results indicate a significant change. In conclusion, a persistent increasing drought trend was detected
for Muğla and western Antalya parts such that all models are coherent. On the other hand, the
divergence of the trends for some regions according to different models signifies the discrepancy of
models. Besides, the drought trends are decreasing for some regions (especially Southern Marmara) as
the timescale increases. Keywords: drought, SPI, CORDEX