[Temporal Dynamics of Stable Isotopic Composition in Lake Taihu and Controlling Factors].

The composition of hydrogen and oxygen stable isotopes in lake water is important to the researches in hydrology, meteorology and paleoclimatology. In this study, long-term and continuous measurement on the compositions of HDO and HO in lake water (δD and δO) was conducted over Lake Taihu, the deuterium excess () was calculated, and the temporal variability and controlling factors were analyzed. The results indicated that ① the variation of isotopic enrichment in lake water was significant, ranging from -59.8‰ to -24.2‰ for δD, from -8.6‰ to -2.6‰ for δO, and from -7.9‰ to 12.9‰ for , respectively. In comparison to cold season, δD and δO were higher and was lower during warm season. ② On monthly time-scale, lake evaporation and the ratio of total water inputs lost by evaporation controlled the isotopic enrichment in lake water. When lake evaporation or the ratio increased, δD and δO increased, but decreased. ③ Over Lake Taihu, the isotopic composition in precipitation and water temperature did not control the isotopic enrichment. The results provide scientific reference for isotope hydrology and the researches related to the isotopic enrichment in lake water in meteorology and paleoclimate.