“GEOMED 2016-The 4th International Geography Symposium”, Antalya, Turkey, 22 May - 26 September 2016, vol.1, no.1, pp.164-173
The Melen Project is a large investment by Istanbul Municipality to meet the water requirements of Istanbul until the year 2071. This project will transform the Melen River Basin into Istanbul’s most important water source. The question is whether the Melen River can actually meet the water needs of Istanbul until 2071. The streamflow characteristics of the Melen River are the fundamental factor that will determine the sustainability of water supply and success of the project. As streamflow is sensitive to changes in precipitation and temperature, changes in climate have the potential to change the long-term outlook for the project. In this study, climatic data for the last 52 years and streamflow data of the last 18 years were correlated to create a streamflow forecast model for the years to come. Regression analysis was performed on daily temperature and precipitation data observed at Düzce Meteorological Station between 1963-2014. Potential evapotranspiration changes were derived from the same data. Streamflow data observed on the downstream section of the Melen River between 1997 and 2014 were used to predict future trends of streamflow. Climatic analysis results show an increase in temperature, reduction in precipitation, increase in potential evapotranspiration and decrease in the streamflow of Melen River. Overall, the trends of climate change and its variability will cause a reduction in water potential and streamflow. As a result, the Melen River will be far from meeting the water needs of the Istanbul in the long run, indicating a significant risk to the Melen project. Key Words: Climate Change, Potential Evapotranspiration, Streamflow, Melen River Basin.