Determining the most appropriate meteorological drought index for evaluation of drought in Hamedan province

If the occurrence of some climatic elements especially rainfall at a given time is less than normal and long term condition, the region will encounter drought. The evaluation of drought in each region needs the quantification of drought. Although none of the indices is superior compared to the others some indices could be more suitable for some users. For this reason, the results of all indices could be different. Main indices investigated in this research were as follows: SIAP, DPI, Z index, PNPI, SPI. The mentioned indices were evaluated using the data of 15 synoptic stations of Hamedan during 20 years, and the best methods were determined. Then, based on that, the map of drought and wet conditions of the province was produced. According to the results, SIAP and Z SCORE were identified as the best compared to the other methods and they could be considered as main indices in the evaluation of drought in Hamedan province.