Vahid Safarian Zengir - Ph.D. of physical geography, Climatology, Faculty of Social Sciences, University of Mohaghegh Ardabili, Ardabil, Iran.
Sahar Amiri Doumari - Graduate of Master of Natural Resources Engineering, Dedesertification, Department of natural resources, Ardakan University, Yazd, Iran.
Leila abdolalizadeh - Master of Art (MA) urban Planning, Urban development department, faculty of art and architecture, Islamic Azad University Science and Research Branch, Tehran, Iran.
Mohammadkia Kianian - Assistant professor of Desert Studies Faculty, Semnan University, Iran.
Ali Afzal Sarikhanbegloo - M.Sc. in Remote Sensing and GIS, Water and Soil Studies, Mohaghegh Ardabili University, Iran.
Mostafa RahKhosravani - M.Sc. in Agricultural Engineering, Faculty of Agriculture, Jiroft Branch of Azad University, Iran.

Drought is a hazardous phenomenon, as a result of climatic parameters abnormalities. The effects of high and low drought occur in different parts of the country, and its effects are more noticeable in arid and semi-arid regions. One of these areas is western Iran, which has been affected by this phenomenon in recent years. The purpose of this study is drought modelling and investigation in western Iran. To do this, climatic parameters were first used, including precipitation, temperature, sunshine, relative humidity and wind speed in ۳۲ years (۱۹۸۷-۲۰۱۸) at ۱۶ stations in western Iran. For modelling the TIBI fuzzy index, at first, four indices (SET, SPI, SEB, MCZI) were been fuzzy in Matlab software, then the indices were compared and finally, by Vikor multivariate decision-making model was used to prioritize areas affected by drought. The results of this study showed that the impact of rainfall on the drought intensity on the ۱۲-months scale is weaker than the ۶-months scale. In the six months, from May ۱۹۹۸ to August ۲۰۰۶, the trend was increasing and then followed the steady pattern, but on a ۱۲-month scale, from August ۱۹۹۵ to December ۲۰۰۱, the trend was increasing and after this month it followed the mostly steady pattern. The highest frequency of drought at ۶ and ۱۲-month scale occurred in Ilam station and its lowest was in Sarpule-Zahab station. The T.I.B.I index accurately reflects the four indicators of SET, SPI, SEB and MCZI. Based on the modelling, T.I.B.I fuzzy index showed relative superiority to the SPEI fuzzy index. Finally, according to the Vikor multivariate decision-making method, the Ilam station with a score of ۰.۹۹ was more prone to drought occurrence. 

Climate change, Management, Surface Water Reduction, T.I.B.I Drought Index, Western Cities of Iran