Possible effects of climate change on surface flows and dams in İstanbul

In this thesis; The effect of climate change on surface waters (dams) and dams was investigated. In order to make a general evaluation in the province of Istanbul, a basin was selected on both the Asian and European sides. Climate analysis is of particular importance as the main theme of the research. In this approach, trend analysis of Florya, Sarıyer, Kadıköy and Şile Meteorology Stations for the period of 66 years from 1950 to 2015 have been made in order to understand the differences in climatic conditions. "Potential Evapotranspiration (PET)", "Excess Water" and "Water Deficiency" were also calculated by Thornthwaite method and their changig trends were examined. De Martonne climate analysis, Erinç rainfall efficiency and Thornthwaite water balance were analyzed for both 66-year averages, and between 1950-1983 and 1983-2015 time intervals. In addition, in order to observe the changes in the climate types in recent years, De Martonne Climate analysis and Erinç rainfall activity index analyzes was made for each month of the year and monthly changes in climate types were analyzed. For the analyze of surface waters, a trend analysis of 38 years of flow data covering 1979-2016 was carried out for the Göçbeyli stream feeding Ömerli Dam Lake on the Anatolian side. On the European side, an analysis was made with 47 years of data covering the years 1970-2016. In this study, rainfall, temperature and produced PET, water deficiency, water surplus data and flow data and filling ratio data were compared and their compatibility and incompatibilities were examined. All of the analyzes show that after 1990's the temperature has increased significantly. This increase shows that the climate types have a tendency to change after 1990. Although it is observed that the rainfall tends to decrease very little in Istanbul, the differences between the years are increasing. It is gradually increasing in PET in proportion to the temperature. When the flow data and dam occupancy rates are considered, the trends are not very compatible and the upward but downward periods are similar.