Stable isotope composition in precipitation and groundwater of Shwan Sub-Basin, Kirkuk governorate, northeast of Iraq

Abstract Stable isotope composition of ?2H and ?18O was investigated in the water resources Shwan sub-Basin northeast Iraq. The study objects conceived possible factors that affect stable isotopes’ precipitation additionally to achieve information concerning recharge processes estimate groundwater sources. In this study, four samples were collected at area for 2020–2021 hydrological year. Thirty-two one surface sample from Lesser Zab River (LZR) during same period two sampling seasons. results observed meteorological data show a very small amount This year is considered dry with total annual 100.62 mm compared previous 40 years 325.43 mm. isotopic highly varied as it primarily depends on environmental conditions. depleted values are recognized increasing amount, whereas enriched most affected by evaporation. Back trajectory analysis revealed isotopes influenced air masses moisture sources came Mediterranean Sea, Arabian Gulf Red Sea would lead variations isotope. showed both periods located between East line (EMWL) global meteoric (GMWL) close local (LMWL) indicating mainly through precipitation. Groundwater recharges an indirect mechanism LZR, based similarity river water. estimated weighted oxygen about 9.2% rainfall infers low. low value experiences weather conditions amounts besides evaporation current study.