Determining the drought trend in the upper euphrates basin

The climate system is shaped by complex interactions between the atmosphere, land, and water cycle. Disruptions in this delicate balance lead to irregularities in precipitation regimes and an increase in the frequency and intensity of drought events. Drought is not only a natural climatic phenomenon but also a major environmental issue that directly affects water resources, agriculture, and ecosystems. Therefore, analyzing past drought conditions and identifying future trends are essential for effective regional water management and climate adaptation strategies. In this study, monthly precipitation data from Elazığ, Erzurum, Erzincan, Bingöl, and Tunceli meteorological stations located within the Upper Euphrates Basin for the period 1965–2020 were analyzed to investigate meteorological drought trends in the region. The main objective of the research is to identify the temporal variability of drought and to compare the results of different analysis methods. To this end, the Standardized Precipitation Index (SPI), Actual Precipitation Index (API), Innovative Trend Analysis (ITA), and Mann–Kendall (MK) test were employed. The SPI results revealed that dry and wet periods alternated irregularly throughout the basin and that short-term droughts became more frequent after the 1980s. The API provided a more realistic assessment of drought duration and severity by directly evaluating precipitation amounts, highlighting prolonged drought periods particularly in the Elazığ and Tunceli stations. ITA results demonstrated fluctuations in rainfall patterns after 1990 and identified hidden trends that traditional statistical tests could not detect. The Mann–Kendall test did not indicate a significant long-term trend across the basin but showed decreasing trends in precipitation for certain stations on a seasonal scale. Overall, the findings indicate that drought events in the Upper Euphrates Basin have become more frequent and persistent over time, while the precipitation regime has become increasingly variable. This situation poses potential risks for the sustainable management of water resources, agricultural productivity, and hydropower generation in the region. In conclusion, the combined use of SPI, API, ITA, and Mann–Kendall methods has provided a comprehensive evaluation of the spatial and temporal characteristics of meteorological drought. The study contributes valuable scientific insight into the impact of climate change on the precipitation regime of the Upper Euphrates Basin and offers a basis for regional drought monitoring and water resource management strategies.