Akademik Veri Yönetim Sistemi
Tezin Türü: Doktora
Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, İnşaat Mühendisliği Bölümü, Türkiye
Tezin Onay Tarihi: 2014
Tezin Dili: İngilizce
Öğrenci: FATİH KARA
Asıl Danışman (Eş Danışmanlı Tezler İçin): İsmail Yücel
Eş Danışman: Sevda Zuhal Akyürek
Özet:This study investigates the impacts of climate change on water resources through precipitation and discharge analyses in Omerli catchment Istanbul, Turkey. Precipitation and temperature data are obtained from GCM (Global Circulation Model)/RCM (Regional Climate Model) combinations based on A1B carbon scenario via Europen Union (EU)-ENSEMBLESproject. The data is obtained at 25 km resolution on daily time scale for reference period between 1960 and 1990 and future period between 2071 and 2100. The HBV (Hydrologiska Byråns Vattenbalansavdel-ning) model is used to investigate discharge properties of study area. First the HBV is calibrated by some of catchment properties along with PEST (parameter estimation) method. Because RCM scale is comparatively coarse (25 km) for catchment scale its results are downscaled to 1 km using the Geographically Weighted Regression (GWR) method. RCM precipitation with and without GWR method are evaluated for characteristics of extreme precipitation events and they are used in the HBV model for estimating the extreme discharges along with reference and future periods. All RCMs strongly underestimate precipitation. GWR improves underestimation tendency of RCMs precipitation especially for extreme events. Depending on precipitation inputfrom RCMs with and without GWR the HBV also shows significant underestimation in daily and extreme runoff but it provides better estimates with GWR input. The magnitude ofextreme events increases in winter, spring, and summer but decreases in fall from reference to future period. Return periods of the extreme events increase in the future period and therefore, Omerli Basin is under water stress with changing climate.