Determination of groundwater and surface water interaction in Baghdad city using isotopes technique

Abstract EN

The stable isotopes of deuterium (2H) and (18O) together with radioactive values of tritium, enhanced by hydrochemical data were used in the current study to identify the interaction between groundwater and Tigris river water in the city of Baghdad.

to achieve this objective, 3 samples of surface water, 3 rainwater samples and 12 samples of groundwater were collected and analysed for 2H, 18O stable isotopes, tritium and hydrochemical analysis.

the hydrochemical parameters of both groundwater and surface water samples show similarity in the wells located in the area of Al-Mansour (WK4), Shulah (WK6), Adamia (WR3) Zafarania (WR1) and Diala (WR4), indicating interaction between surface and groundwater in these areas.

moreover, the stable isotopes results show that the difference between the values in groundwater and surface water samples is small and they are close to each other, which also indicates that the surface water in the study area interact with some groundwater, as shown in samples from wells at Al Dora (WK1), Saidia (WK2), Karadha Mariam (WK3), Rahmania (WK7), Zafrania (WR1) and Diala (WR4).

The interaction between surface and groundwater in these areas is confirmed by the results of the environmental isotopes (H), where the values are very close in the samples collected from these sites.

the present study also showed that the composition of the hydrogen and oxygen isotopes from river water matched with the local meteoric water in the Tigris river basin.

this indicates that rainfall has a major contribution to the river water.

therefore, the groundwater might be a mixture of river water and rainwater and the composition of isotopes is controlled by the mixing rates of surface water, internal flow and groundwater components.