Scope of the field of study is Akarçay Closed Basin. The scope of the subject; 3 Meteorological stations (Afyonkarahisar “1970-1995”, Bolvadin “1970-1990”, Akşehir “1970-1995”) with 3 current observation station (Sivrikaya Creek “1970-1995”, Akarçay-Bolvadin “1970-1995”, Akarçay-Balca “1991-2005”) using the average flow data, and conduct trend analysis of evaporation parameters constitute. Besides, the aim of the study is also to analyze the summer seasonal and summer months trends of these data by considering the monthly measured average evaporation data of meteorological and flow observation stations observed over many years across the basin. The topic has been selected because of the great significance of endorheic basins with the idea that changes in climate parameters are easier to notice in such areas. In addition, the study will also contribute to the national and international literature on climate change studies with another example from Turkey. The research method is based on the Mann-Kendall Test, Spearman's Rho Test and Sen Test. According to the results obtained, significant increase trends in evaporation (Akşehir and Bolvadin) were observed throughout the basin during the summer season, while non-significant increase trends were determined at Afyonkarahisar station. A significant/insignificant increases in the flow are observed at Sivrikaya stream and Akarçay-Balca stations, while a significant decrease trends are observed at Akarçay-Bolvadin station located in the lower part of the basin. Finally, Eber and Akşehir Lakes, which are wetlands in the basin, are at risk due to reduced water levels. An urgent action plan should be prepared and implemented.
Akarçay closed basin, flow, evaporation, Mann Kendall, Spearman Rho, Sen test