Abstract
The wet and drought periods of a basin for many years generate themselves as changes in precipitation and differences in streamflow data. Flood and drought problems may arise in certain time periods as a result of global climate change. In order to reduce the potential negative effects of these two problems, making analyzes using the observed past records will provide an accurate and effective approach in terms of future prediction works. In this study, the Fırtına Creek Sub-basin (Rize-Çamlıhemşin), which has recently been pointed out to decrease on the flow rate values and noticed serious drought effects in the existing water resources, was preferred as the case study. With the Standardized Runoff Index (SRI) method, the wet and drought period values on 3, 6, 9 and 12-months have been obtained using the past data of the Flow Observation Stations (FOSs). The data belong to the Former Electrical Works Survey Administration (EIEI) with the number of 2232 for the years of 1965-2011 and the State Hydraulic Works (DSI) with the number of E22A067 for the 2012-2015 ones, respectively. The time period has been investigated in four separate sections as the years of 1965-1979, 1980-1995, 1996-2011 and 2012-2015. As a result of this study, it has been observed that Severe and Extremely wet periods occurred from 2005 until 2013 while the drought periods were more intense than wet conditions between 1965-2005 years. The fact that the number of drought years between 2012 and 2015 has an increasing trend compared to the wet years with regard to different time scales, can require taking precautions against the drought event in the future.