Influence of Evaporation on the Hydrogen and Oxygen Stable Isotopes in an Enclosed Water Body: A Case Study

Abstract

It is of great significance to study the influence of evaporation on the protection and management of regional water resources. In this study, water samples have been collected from a typical enclosed water body, Liuxi, a small brook in the campus of Suzhou University in May and June, and then analyzed for their hydrogen and oxygen stable isotopes. The results indicate that the samples collected in June have higher d18O and dD values relative to the samples collected in May, and both of them have d18O and dD values plotted at the right of the meteoric line, in combination with their lower deuterium excess (d-excess) values relative to the meteoric line, implying that the water has been influenced by evaporation. Moreover, the d-excess values showed decreasing and increasing in different sampling sites, which was demonstrated to be influenced by different extents of evaporation. Based on the calculation, the residual water quantities were 70–75% and 51–70% for May and June relative to the initial water, which indicates that about 10% of the water had evaporated during May and June.

Keywords

• isotopes, d-excess, influence of evaporation, water resource protection