Water Balance for the City of Al-Najaf Al-Ashraf/Southern Iraq

Al-Najaf Al-Ashraf city located, in the southern part of Iraq, is located between latitudes (29o 50 00̋ 32o 21 00) north and longitudes (42 ° 50 '00 "45 ° 44' 00") east, The rocks exposures at the study area date back to the (Middle Miocene-Recent) and this includes Dammam, Euphrates, Fatha, Injana, Zahra and Dubduba formations as well as Quaternary deposits. Depending on the climatic data recorded in Najaf station for the period (1994-2014) show that the total falling rain was (97.54) mm, and the average temperature (25.75 C°), relative humidity (41.52%), wind speed (1.67 m / s), sunshine (8.6 hours / day) and the total evaporation from free surfaces was (3473.46 mm). The prevailing climate in the region is dry to semi-dry. was calculated corrected potential evapotranspiration theoretically apply Thornthwaite method where she was value 1024.97 mm, was also calculate the water surplus , which accounted for 22.1% divided into surface runoff and and Groundwater Recharge while the water deficit represents 77.9% of the annual rainfall.