Changes and trends of seasonal total rainfall in the province of Istanbul, Turkey

Changes and trends of seasonal total rainfall in the province of Istanbul, Turkey Abstract: Several studies revealed that climate change can affect local and regional precipitation patterns. Long term trends and cycles in precipitation is important for the health of ecosystems in the region. The possible impacts in near future can affect the forest and water resources of Istanbul.  In this study, daily, monthly, seasonal and annual precipitation analyses for the different meteorology stations were examined for the Istanbul province. Northern and southern different climatic conditions of Istanbul have been effective selection of the station. The Mann-Kendall test results showed that there is positive statistically significant trend in some meteorology stations. According to Mann-Kendall results the increased fall precipitation trend were found in Florya, Kirecburnu ve Kumkoy meteorology stations and decreased summer precipitation trend were found in Goztepe meteorology stations Keywords: Mann-Kendall trend analysis, precipitation time series, the regional precipitation reactions analysis, climate change Istanbul ilinde mevsimsel toplam yagislarin degisimleri ve egilimleri Ozet : Iklim degisikliginin bolgesel ve yoresel olcekte yagis rejimi uzerinde etkileri olabilecegi bircok arastirma ile ortaya konulmustur. Yagis serilerindeki uzun donemli yonelimler ve donguler yoredeki ekosistemlerin sagligi ve gelecegi acisindan buyuk onem arzetmektedir. Istanbul ilinde onumuzdeki donemde gerceklesebilecek etkiler ise hem su kaynaklari hem de ormanlar uzerinde onemli sonuclar ortaya cikarabilir. Bu calismada Istanbul iline ait farkli meteoroloji istasyonlarinin uzun donemli mevsimlik verileri arastirilmistir. Calismadaki amacimiz ileriye donuk tahminlerdeki belirsizlikleri belli oranda ortadan kaldirabilecek gecmise donuk veriler yardimiyla istatistiksel analizleri gerceklestirmektir. Istasyon seciminde Istanbul’un kirsal ve kentsel bolgelerindeki farkli iklim kosullari etkili olmustur.  Mann-Kendall testi sonuclarina gore Florya, Kirecburnu ve Kumkoy Meteoroloji Istasyonlari’nda secilen sonbahar mevsimi yagislarinda, Goztepe Meteoroloji Istasyonu’nda ise yaz mevsimi yagislarinda istatistiksel anlamda artan bir trend bulunmustur. Anahtar kelimeler: Mann-Kendall trend analizi, yagis zaman serileri, iklim degisikligi Received (Gelis):  10.02.2016 -  Revised (Duzeltme):  05.05.2016 - Accepted (Kabul):  24.05.2016 Cite (Atif):  Yurtseven, I., Serengil, Y., 2017. Changes and trends of seasonal total rainfall in the province of Istanbul, Turkey.  Journal of the Faculty of Forestry Istanbul University  67(1): 1-12. DOI: 10.17099/jffiu.30673