Determination the optimal prediction scenario for the future precipitation rates in the Al-Najaf Governorate in Iraq

Statistical downscaling models are recently used to predict the future events of climate change. A model is built for Al-Najaf Governorate, Iraq depending on the daily observed data 2010-2020 with the aim of predicting the future precipitation's projections of the decades from 2030 to 2100. Identifying the best, ideal and precise scenario that fit the study area to predict the future precipitation values is done. Calibrating the statistical downscaling model of Al-Najaf Governorate has given good results comparable to the observations. CanESM2_rcp8.5 scenario results the best values of standard deviations which qualifies it to be the best scenario for anticipating the future precipitation's events. Results indicate a slight increase in precipitation for the decades 2030-2070. In December 2080, the rainfall will increase by 18 mm, while rainfall records a 23 mm increment in January 2080, 2090 and 2100. The implicit years of the predicted decades reveal rainfall (10-18) mm (autumn) and (15-23) mm (winter).