Isotopic composition (δ¹⁸O and δD) of the shallow groundwater in the Poyang Lake basin

The article is focused on the identification of evaporation and other natural processes which affect the isotopic composition of shallow groundwater in the Poyang Lake basin, such as water-rock interaction and mixing of the shallow groundwater and surface water. For this purpose the dual isotope approach (δD–H₂O and δ¹⁸O–H₂O) was used. The samples were collected from domestic wells around the Poyang Lake. The value of δD obtained for the shallow groundwater ranges from -21.5 to -42.6^∘/_∘∘. The δ¹⁸O value varies from -3.5 to -7.1^∘/_∘∘. It was found that the shallow groundwater of the Poyang Lake catchment is of meteoric origin. The influence of evaporation on the isotopic composition of shallow groundwater is negligible and observed mainly during the dry season. The deviation from the local meteoric water line, especially during the rainy season, may be explained by the processes in the water-rock system, but this issue is required further research.