using of spi and pn index for determination of drought in the fars province

aridity and drought are two inevitable occurrences of the climate change in the region. so, any kinds of planning and futurism, without regard to them, lead to failure. climate change cause drought phenomenon. the anomalies and irregularities in the precipitation mainly cause drought. fars province, one of the important centers of agriculture, population and industry in the country, with specific climate in terms of the phenomenon of drought experienced the reduction of agriculture production. so in the study area, the aim is the determination of drought from 2008 to 2014 in the fars province. in order to the determination of drought standardized precipitation index (spi) and percent of normal index (pni) were used. the results using spi and pn show that the amount of drought is variable in the different years. also the results of pn and spi showed some differences. so in order to evaluate and select the best method 10 sample points were used. the results showed that spi is better that pn for the prediction of drought. also mlr model was used to determine the relationship between indices and rainfall. the results of mlr model showed that using rainfall can predict the drought for the study area.