Assessi̇ng spatio-temporal tendencies of meteorological drought by different methods:A case study in Sanliurfa

Global warming is considered among the most important causes of climate change. The increase in the frequency and severity of natural disasters such as floods, droughts, etc. in recent years is considered as a sign of climate change. In this context, the study conducted in Sanliurfa province, which has a surface area of 19.242 km², aimed to determine the spatial and temporal distribution of meteorological drought in 2 different periods by De Martonne (IDM), De Martonne-Gottman (IDMG) and Erinç (Im) methods. Long-term monthly total precipitation (mm), average temperature (ºC) and average maximum temperature (ºC) series obtained from 12 meteorological observation stations located within and outside the provincial borders were used as the basic material. Annual drought index values were calculated for each station using three methods. The missing years in the calculated drought index series were completed by correlation and regression analysis between stations with missing years and stations with complete series length. Taking the year 1991, when Atatürk Dam started to hold water, as the starting year of the 2nd period, the series of the stations were divided into 2 different time scales as the 1st period (1961-1990) and the 2nd period (1991-2020). Using the median values of the drought index series representing the stations, IDM, IDMG and Im annual climate class maps of Sanliurfa were produced for 2 different periods with a resolution of 200x200 m by the Inverse Distance Method. As a result; according to IDM, IDMG and Im methods, it was found that the spatio-temporal spread of meteorological drought in Sanliurfa province is from south to north; drought severity increases in the south in the 2nd period and there is no significant difference between the methods. Atatürk, Birecik and Karkamis dams were found to be unable to prevent the spread of drought from south to north.