Abstract
The frequency and intensity of drought events have increased due to the increasing impact of global warming for the last 20 years. Drought primarily affects agricultural activities, as approximately 70% of freshwater resources are used in agricultural production. Sanlıurfa province, located in the Southeastern Anatolia Region and one of the regions struggling with drought, is known for its intense agricultural production. Therefore, it is important to take measures against drought in Sanlıurfa province. The purpose of this research is to investigate the usability of aSPI (Agricultural Standardized Precipitation Index) and eRDI (Effective Reconnaissance Drought Index) methods, which are newly used in the literature and provide more sensitive results in agricultural drought analysis, in Sanlıurfa province. In addition, the causes of droughts have been tried to be understood with research on the trends in temperature and precipitation data. Consequently, agricultural drought analyses were conducted with aSPI and eRDI modified methods. Drought analyses were also performed with SPI (Standardized Precipitation Index) and RDI (Reconnaissance Drought Index) methods and compared with modified methods. In this study, 31 years of precipitation and temperature data between 1993 and 2023 of Sanlıurfa province were obtained from the Meteorology General Directorate (MGM). The analysis results based on aSPI and eRDI show similarities with the original SPI and RDI analysis results. However, the drought classes of some years were different. While 2017 was severely arid in the original methods, it was extremely arid in the modified methods. In addition, the years 2014, 2015 and 2023, which were mildly arid in most methods, were not mildly arid in some methods. In addition to the main purpose of the research, findings of the Mann-Kendall trend analysis, based on the 0.05 significance level, determined that the annual minimum and maximum temperatures are trending upward. For this reason, it was determined that rising temperatures are increasing drought. For this reason, it is necessary to take action to lower evaporation, especially in the summer months in Sanlıurfa province. The use of aSPI and eRDI methods should be expanded in the investigation of agricultural drought.