Study and compare performance of four meteorological drought index in the risk management droughts in Sistan and Baluchestan province

Study of drought situation is important in various areas in editor plans to deal with the drought and risk management. Rainfall is one of the most important variables that are used in defining drought. Several index is presented to assessment for drought based on rainfall. Study simultaneous occurrence of certain classes of states of the drought index can be appropriate criterion for conformity assesment indicators. The purpose of this research is study the performance indexes of drought in Sistan and Baluchestan province، and select the appropriate index. To achieve this goal، used of data annual rainfall from 1360 to 1389 and using an index of normal (PN)، The rainfall deciles (DPI)، the Standardized Precipitation (SPI)، Precipitation anomalies (RAI) in 7 meteorological stations in Sistan and Baluchestan province، drought have been studied and was classified. To select the most appropriate index was used of sperman correlation coefficient between the index drought and rainfall changes in the period under study. Results showed that، in cities Zahak، Zabol، Iranshahr and Chabahar PN index with correlation coefficient (1)، in the cities of Zahedan and Saravan RAI index by coefficient 0/84 and 0/99 and in Khash SPI index by correlation coefficient (1) could show very severe and extreme drought better than other indicators. In evaluating the correlation between paired indicators، PN-RAI، PN-SPI and SPI-RAI have a high correlation to each other the Possibility level (p <0/01) in most of stations.