An evaluation of spatiotemporal changes of meteorological drought in the Mediterranean sub-basins in Türkiye using discrepancy precipitation and standardized precipitation index

Detecting dry and wet periods is crucial for regions susceptible to drought impacts. The present study analyzed the dry and wet periods using precipitation data obtained from 8 gauging stations along the Central Mediterranean coast of Türkiye. A span of 52 years, from 1970 to 2021, was examined utilizing three distinct methods: the Standardized Precipitation Index (SPI-Gamma, SPI-Lognormal), Discrepancy Precipitation Index (DPI), and Reconnaissance Drought Index (RDI). Initially, the study discussed the changes in dry and wet periods observed at the respective stations. Subsequently, it determined the transition probabilities associated with classifications of drought. The results showed that SPI-G values exhibit greater precision in detecting wet periods, while the SPI-L method yields more specific outcomes in identifying dry periods. Notably, the DPI method demonstrates a higher frequency of dry periods than the SPI method. Additionally, findings from the SPI method suggest that reductions in drought indices correspond to an increased occurrence of drought. The DPI method’s outputs indicate fewer occurrences of wet periods across all stations in contrast to the results obtained through the SPI method. The study stands out by addressing the assessment of drought development in the Mediterranean coastal regions of Türkiye using the DPI method, which has recently garnered attention in the literature, presenting a novel contribution within the scope of this research.