Estimation of Groundwater Recharge Using Chloride Mass Balance (CMB) Unconfined Aquifer in Kirkuk Sub-Basin/ NE Iraq

An estimation of groundwater recharge for the unconfined aquifer in Kirkuk - Iraq sub-basin, has been conducted using chloride mass balance method by measuring the monthly chloride concentration in monthly basis for rainy (wet) season 2015-2016 , samples have been selected from 44 water wells scattered in the region of interest ,the results shown that the groundwater recharge is about 15.6% from the total annual precipitation (304.3 mm) where the total recharge reached ~ 47.5 mm, moreover an additional source of fresh water is feeding the region of interest represented by Kirkuk irrigation channel ,the discharge is nearly 7 m3/sec for 360 days ( 218 MCM/Year). the total amout of recharge to Kirkuk sub-basin is equal to 411 MCM/Year. The discharges of Al-Khassa river which crossed the central parts of ROI, were neglected because the river became controlled by Al-Khassa dam which was recently constructed at the northern border of the ROI which represented by Kirkuk structure. The present study is recommended to use this source of renewal water through strategic plan where additional comprehnsive hydrologic studies and aquifer modeling are needed to prevent the groundwater depleting in the region.