Long-Term Temperature and Precipitation Trends in the Turkish Section of the Euphrates-Tigris Basin

Abstract This study examines the long-term trends of key meteorological variables within the section of the Euphrates-Tigris Basin located within Türkiye’s national borders. Using data from 18 meteorological stations (1965-2023) and applying methods such as the MMK test, SS, SR, and several homogeneity tests, the analysis identifies notable climatic shifts. The combined use of these methods allows for a more consistent evaluation of both trends and potential structural changes in the time series. Significant decreases in precipitation were detected at three stations, while the remaining stations showed no clear trend. This indicates that precipitation changes are limited and station-specific, reflecting spatial variability within the basin rather than a uniform basin-wide pattern. In contrast, maximum temperatures increased significantly at 77.8% of stations, and minimum temperatures rose at nearly 83%. The widespread increase in temperature across most stations suggests a more consistent warming pattern compared to precipitation. Homogeneity assessments revealed major change points in 1989, 1994, and 1998 for both precipitation and temperature. These years may be associated with variations in atmospheric circulation patterns and regional hydro-climatic influences, including reservoir-related effects. The identification of similar change points by different homogeneity tests supports the consistency of these findings. These results suggest an increasing hydro-meteorological imbalance, likely influenced by rising temperatures and declining or stable precipitation. These changes may have an impact on the hydrological processes within the catchment area and on water-dependent sectors. The findings highlight the urgent need for long-term, adaptive, and integrated water management strategies, supported by basin-specific climate change scenarios.