Sakarya Nehri Havzası’nda Sıcaklık, Yağış ve Akarsu Rejiminde Meydana Gelen Değişikliklerin İncelenmesi(Examination of Changes in Temperature, Rainfall and Stream Regime in Sakarya River Basin)

Abstract

In this study, changes in temperature, rainfall and flow amounts and regimes in the Sakarya River Basin in northwest of Turkey over the years were examined. For this, the observation time of the current series set (1965- 2011) was divided into 3 periods and the results of these periods were compared with each other. Graphs and tables have been created by using monthly flow data of 5 stream observation stations in the basin and monthly temperature and precipitation data of meteorology stations. According to the temporal analysis, the tendency to increase in temperatures was determined. It can be said that it is the hottest period between 1995-2011, which is the last of the three periods. Especially during this period, the average temperatures in the summer rose even more. 3 of the meteorology stations (Sivrihisar, Polatlı, Eskişehir Region) are located in the Central Anatolian Rainfall Regime and 2 (Geyve, Bolu) Marmara Rainfall Regime. There is a change in Sivrihisar's precipitation regime in the period of 1995-2011. Precipitation characteristics resembled the Mediterranean-Central Anatolian Transition Type in this period. Bolu, on the other hand, shows a close proximity to the Terrestrial Rainfall Regime 1 in the 1980-1994 period. There is no change in precipitation regimes of the other 3 meteorology stations. Generally, there is a decrease in the flow amounts of the stream observation stations. However, no regime change was observed.