Hydrological data such as daily, monthly, and yearly peak discharge rates, ... etc., are being used in flood frequency analyses. Because the phenomena have inherent random character, the value to be observed in the future can only be determined by probabilistical and statistical laws. This kind of data should show independent, homogeneous and random behavior so that it can be used in the simulation and frequency analyses. In this study, initial stage studies needed to be done and some simple basic statistical analysis techniques have been examined so that observed discharge data in an example river basin could be used in this kind of analyses. These analyses techniques were applied to annual peak discharge data recorded by flow gauging stations in Middle Anatolian Closed Watershed and flow's trends were determined by testing results at 5 percent confidence level.

Hydrological data such as daily, monthly, and yearly peak discharge rates, ... etc., are being used in flood frequency analyses. Because the phenomena have inherent random character, the value to be observed in the future can only be determined by probabilistical and statistical laws. This kind of data should show independent, homogeneous and random behavior so that it can be used in the simulation and frequency analyses. In this study, initial stage studies needed to be done and some simple basic statistical analysis techniques have been examined so that observed discharge data in an example river basin could be used in this kind of analyses. These analyses techniques were applied to annual peak discharge data recorded by flow gauging stations in Middle Anatolian Closed Watershed and flow's trends were determined by testing results at 5 percent confidence level.