The local meteoric relationship for 18O and 2H in precipitations and isotopic compositions of water resources in northeast Amara area (South of Iraq)

Abstract

This paper focuses on determining the Amara meteoric water line for the study area (AMWL) is defined or the first time, based on samples of precipitation collected Amara city - southeast of Iraq. For an adequate management of available water resources in semi-arid and arid regions, it is important to compare isotopic data of surface water and groundwater with the local meteoric relationship for d18O and dD in precipitations.Isotope values of precipitation indicate a local meteoric water line (Amara MWL δ2H = 7.51 δ18O + 10.82; R2=0.94) situated between the Mediterranean MWL and Global MWL. Both the slope and 2H intercept for AMWL are deviated from the global meteoric water line - GMWL (δ2H = 8.13 18O + 10) and Mediterranean MWL (δ 2H = 8.13 18O + 22). The slightly variation in isotopic compositions of the Missan rain (from -4 to +3.2‰ and from -20 to -14‰ for 18O and 2H, respectively) is because of slightly seasonal changes in precipitations in this area. The 18O and 2H isotopes of local water resources show that the rainwater is affected by the Arabian Gulf Arabian Sea potential moisture sources.