investigating the relationship between spi and unep aridity indices with trend of the dust storm index in the central region of iran

The dust phenomenon has many dangers for human society and is of special importance for the residents of iran. different researchers have studied this phenomenon from different angles. in terms of the significance of the subject and the dangers arising from it, it is still at the top of the topics of interest of researchers all over the world. this research aims to use dsi, unep and spi indices in the evaluation and zoning of dust storms in semnan province. in this research, the temporal distribution of dust storms in semnan, taking into account the weather conditions and the average wind speed of the study area during the years 2003 to 2017, was investigated in five synoptic stations. the homogeneity of climatic parameters and dust storm indices and the trends of these two variables were calculated using linear regression in the spss software environment, and after examining the changing trend of the unep index, the resulting information was zoned in the arcgis software environment. correlation between drought indices, rainfall standard, and dsi shows that the dsi index has increased during the analyzed period at the same time as the severity of drought increased and its correlation with spi during the 15 years was significant (r2=0.89). these results showed that increasing the amount of drought index has a positive effect on increasing the amount of drought index, also the occurrence of dust storms has increased with the increase of the drought index.