SURFACE WATER-GROUNDWATER INTERACTION IN DIWANIYA, SOUTHERN IRAQ USING ISOTOPIC AND CHEMICAL TECHNIQUES
The stable isotopes of 2H, 18O, and 3H reinforced by hydrochemical data, were used to identify the interaction between groundwater and Shatt Al-Diwaniya water and estimate the age of groundwater in the research area. For achieving these two goals, twenty-two samples of water were collected at the suggested area through a sampling campaign for twelve shallow wells, three from Shatt Al- Diwaniya, six rainfall samples, and one sample of sewer water. Three additional samples were collected for comparison from outside of the study area. The results of stable isotopes and hydrochemical composition indicated that there is a similarity between shallow groundwater samples and Shatt Al-Diwaniya water. The surface water interacts with groundwater for all boreholes, except for the borehole in the Al-Jameih District (WR2), which showed similar results spring water as comparing with SW1 and SW2 spring water samples. The isotopic composition of Shatt Al-Diwaniya (2H and 18O) is close to the local, and meteoric global water line, this indicates that the rainfall makes a significant contribution to the water of Shatt- Aldiwaniya. There is a convergence with the values of isotopes of wastewater and groundwater, which indicates that the formation of shallow groundwater is a mixture of Shatt Al-Diwaniya water and the recharge (wastewater and rainfall). The results of 3H concentration remaining in shallow groundwater showed that the age of the groundwater ranges from1.8 to 6.3 years, this indicates that recharge of shallow groundwater is modern.