TEMPORAL DROUGHT ASSESSMENT USING VARIOUS INDICES OF THE SEYHAN AND CEYHAN BASINS, TURKEY

Drought is a natural phenomenon with various social, environmental, and economic effects. Adverse impacts of drought at a regional and global scale have become more evident with climate change. The Seyhan and Ceyhan basins were chosen as study areas in Turkey. Drought analyses were performed using data from 14 meteorological stations gathered between January 1989 and July 2020 in Standardized Precipitation Index (SPI) and Standardized Precipitation Evapotranspiration Index (SPEI), based on 3-4-6-12 monthly scales. SPI and SPEI are common indices used for drought tracking. The coefficient of determination (R-2) was found to be 0.954 and used to analyze the regression between the annual SPI and SPEI. According to SPI and SPEI annual analyses results of study area, the driest year was found to be 2014. SPEI determined more arid periods than SPI for the same time scales. Analyses reveal that the dry period in basins has increased in the last decade and the region is facing a risk of drought. Analyses were made to predict and evaluate risks and to help the efficient use of agricultural lands and water resources in the study area during dry periods.