Statistical analysis of monthly and annual stream flow of Sakarya river and its correlation with rainfall in the river basin

The researching area of this study is the Sakarya River, which rises from Central Anatolia Region and empties itself into the Marmara Sea, and its river basin.The Sakarya River which has 810km.of length and 56,504 km2 of river basin is one of the important rivers of Turkey.In this study, the monthly and annual streamflows of the Sakarya River and its arms and the monthly and annual rainfall values of big conditioner stations in the river basin have been investigated as statistical.As trend analysis t test and the test of Mann- Kendall have been applied. In addition, the degree of interaction between streamflow and rainfall has been tried to explain with the method of correlation coefficient. According to results, rainfall- streamflow correlation increases at the winter months when the amount of rain is much but it decreases at other months that the amount of rain is little.The streamflow values of the Sakarya River and its arms have showed a decreasing direction because of irrigate systems and changed conditions of climate. However the decreasing trend has not been seen as well as streamflow in the basin rainfall.