Evaluation of annual total precipitation in the transboundary Euphrates–Tigris River Basin of Türkiye using innovative graphical and statistical trend approaches

Abstract The Euphrates–Tigris River Basin (ETRB), one of the largest river basins in Middle East, is also among most risky transboundary world. ETRB has a critical importance for region both politically and economically due to its location. Evaluating increasing regional impacts climate change even more important sustainable management water soil resources, especially such as ETRB. Türkiye riparian countries part constitutes headwater basin. In this study, temporal variability annual total precipitation data period 1965–2020 eighteen stations located was investigated. Classical Mann–Kendall (MK) test used statistically determine monotonic trend precipitation. addition MK method, analyses were carried out with three innovative methods, which have ability interpret trends graphically. These methods are ?en analysis (?en-ITA), Onyutha (OTT) combination Wilcoxon scatter diagram (CWTSD). results obtained show that there decreasing according all generally examined period. addition, from relatively new OTT CWTSD strong consistency other two methods. advantages performing numerical visual identifying low–medium–high value detecting sub-trends shown these can be an alternative widely ?en-ITA.