Determination of Sudden Changes in Time Series of Yesilirmak River-durucasu Water Quality Records

A variety of methods and statistical tests are being used to identify existence of trends in time series of water quality parameters. In this study, it was attempted to identify trends and sudden changes for selected water quality parameters at the Yesilirmak River-Durucasu monitoring station. For this purpose, time series of grouped time periods, which do not exhibit inhomogeneity in median and variance values among years, were constituted for each water quality parameter using graphical methods and non-parametric tests. Considering test results, even though different time periods were observed for each water quality parameter, in general, two sudden changes in time series of most water quality parameters were obtained in 1989 and 1998.