Analysis and comparing several climate droughts indicators and determine the best index in southeast of Iran

the drought is the most destructive weather events which cause significant causes both in natural resources sector and human’s life. The aim of this research is to compare the performance of drought’s indexes and determining the best index in the region of southeast of Iran. To this purpose with using 30 year of daily precipitation data (1985-2014) from meteorological organization and with using 8 most widely used indexes such as standard precipitation, rainfall anomalies, percent of normal, annual precipitation, Niche, the standard score, deciles and Chinese Z in 19 meteorological stations of Kerman, Hormozgan and Sistan va baloochestan the accuracy of each indicators examined in determining the drought intensity. Also the zoning has done in arc GIS9.3 for the driest year in the statistical time period and comparing the most severe drought category in 2 selected index. The accuracy of each index analyzed in 2 annual and monthly scales. In annual scale is used the efficient measures of minimum precipitation’s symmetry years with most severe droughts in region’s stations. The results showed that in the monthly scale in order to analyze the southeast drought of the country the dynamic index of standard precipitation (SPI) in a time period of 6 and 12 month had the best function. But in annual scale the rainfalls anomalies indexes (RAI) and Docile (DI) in all the stations had showed the minimum precipitation amounts with severe droughts which determined as the best index. Also the Niche index had the weakest function in determining the drought intensity in southeast of Iran’s stations.