Comparison of Some Drought Indices in Iraq

Drought in Iraq was assessed using three drought indices for two different time periods, past period from 1970 to 2015, and future period from 2016 to 2050 for 4 stations in Iraq. These indices named: the Standardized Precipitation Index (SPI), Percentage of Precipitation Anomaly (PPA), and Z-Score Index (ZSI). The main sources of data were the monthly rainfall archive from Iraqi Meteorological Organization and Seismology (IMOS) for past period, and projection monthly precipitation data from Representative Concentration Pathway scenario (RCP4.5) for Fifth Assessment Report (AR5) affiliate to the Intergovernmental Panel on Climate Change (IPCC) for future period. The results shown good correlation of among 3 indices, with different rank of them, were lowest rank was 0.85. The three indices refer to were good evaluate the drought severity of Iraq. Found too the best index was PPA during past period, and the significant index was ZSI for the future period. The North of Iraq (Mosul Station) was the least vulnerable to drought from the analysis of the results of the three indices for the last period, where the number of dry seasons were 12 on the basis of the PPA classification. South of Iraq (Basra station) has the highest number of wet season on the PPA rating were (15) season.