Spatial variability of precipitation regimes over Turkey

Turkish annual precipitation regimes are analysed to provide large-scale perspective and redefine precipitation regions. Monthly total precipitation data are employed for 107 stations (1963–2002). Precipitation regime shape (seasonality) and magnitude (size) are classified using a novel multivariate methodology. Six shape and five magnitude classes are identified, which exhibit clear spatial structure. A composite (shape and magnitude) regime classification reveals dominant controls on spatial variability of precipitation. Intra-annual timing and magnitude of precipitation is highly variable due to seasonal shifts in Polar and Subtropical zones and physiographic factors. Nonetheless, the classification methodology is shown to be a powerful tool that identifies physically-interpretable precipitation regions: (1) coastal regimes for Marmara, coastal Aegean, Mediterranean and Black Sea; (2) transitional regimes in continental Aegean and Southeast Anatolia; and (3) inland regimes across central and Eastern Anatolia. This research has practical implications for understanding water resources, which are under ever growing pressure in Turkey

Projecting climate change, drought conditions and crop productivity in Turkey

This paper focuses on the evaluation of regional climate model simulation for Turkey for the 21st century. A regional climate model, ICTP-RegCM3, with 20 km horizontal resolution, is used to downscale the reference and future climate scenario (IPCC-A2) simulations. Characteristics of droughts as well as the crop growth and yields of first- and second-crop corn are then calculated and simulated based on the data produced. The model projects an increase in air temperature of 5 to 7°C during the summer season over the west and an increase of 3.5°C for the winter season for the eastern part of the country. Precipitation is predicted to be 40% less in the southwest, although it may increase by 25% in the eastern part of the Black Sea region and northeastern Turkey. Trends in drought intensity and crop growth are related to climate changes. The results suggest more frequent, intense and long-lasting droughts in the country particularly along the western and southern coasts under future climate conditions. A shift of climate classes towards drier conditions is also projected for the western, southern and central regions during the 21st century. Evaluating the role of the climate change trends in crop production reveals significant decreases in yield and shortened growth seasons for first- and second-crop corn, a likely result of high temperatures and water stresses. In addition to rising temperatures and declining precipitation, increasing frequency, severity and duration of drought events may significantly affect food production and socio-economic conditions in Turkey. Our results may help policy makers and relevant sectors to implement appropriate and timely measures to cope with climate-change-induced droughts and their effects in the future