SIMULATION AND ANALYSIS OF NATURAL HAZARD PHENOMENON, DROUGHT IN SOUTHWEST OF THE CASPIAN SEA, IRAN

As a result of atmospheric anomalies and lack of rainfall occur Droughts. Drought occurs in arid and semi-arid regions of the world. no place in the world is protected from drought. Everywhere in different regions of the world there is a shortage of precipitation and rising temperatures they appear as drought. One of these areas is southwest of the Caspian Sea, which suffered from this phenomenon in recent years. The purpose of this study is to model, analyze and predict the drought in Northwest of Iran. To do this, climatic parameters (precipitation, temperature, sunshine, minimum relative humidity and wind speed) of 21 stations were used in the period of 31 years (1988-2018). For modelling of the TIBI fuzzy index, first, four indices of Standardized Evapotranspiration Torrent White Index (SET), Standardized Precipitation Index (SPI), Standardized Evapotranspiration Blanney Creedal FAO Index (SEB) and Modified CZI Index (MCZI) have been fuzzy in Matlab software. Then the indices were compared and the Topsis model was used for prioritizing areas involved with drought. Results showed that the new fuzzy index of T.I.B.I for classifying drought reflected four above indicators with high accuracy. Of these five climatic parameters used in this study, the temperature parameter had the most effect on the fluctuation of drought severity. The severity of the drought was more based on a 12-months scale modelling than 6-months. The longest drought persistence in the study area occurred in Urmia Station in the 12-month period from July 2003 to December 2004. The highest percentage of drought occurrence was at Urmia station on a 12-month scale and the lowest was in Sanandaj station on a six-month scale. According to the results of the present study, areas and stations that will be affected by drought in the future. This problem can be overcome by careful planning.