عنوان مقاله [English]
By analyzing the historical records of the drought phenomenon and relying on the available statistics and information, it is possible to estimate the period of drought returns for different regions. By creating drought preparedness plans, the problems caused by drought can be greatly reduced. Frequency along with severity, duration and range are the most important features studied in drought studies. The purpose of this study was to calculate the relative drought frequencies of the Persian Gulf basin with the help of the standardized precipitation evapotranspiration drought index (SPETI) and to prepare a map of their frequencies. For this purpose, SPETI index was used as a selected index to study droughts in 10 stations located inside and outside the basin with a common statistical period of 30 years (1988-2017) in four scales of 12, 9, 6 and 3 months. After reviewing the output results, the relative frequencies of drought were extracted and mapped at each scale. Trend graphs of precipitation and temperature showed that the annual data of precipitation and temperature had a decreasing and increasing trend, respectively, with a temperature increase of 28%; hence, the results showed that SPETI index in presenting drought phenomena was faced with an increase in temperature and a decrease in precipitation. Therefore, these stations are introduced as stations with the potential for drought sensitivity.