Spatial and temporal patterns of stable water isotopes along the Yangtze River during two drought years

摘要: Changes in the level of Yangtze River caused by anthropogenic water regulation have major effects on hydrological processes and cycle surrounding lakes rivers. In this study, we obtained isotopic evidence changes during two drought years 2006 2013. Isotopic demonstrated that δ18O δD levels exhibited high spatial heterogeneity from upper to lower reaches, which were controlled atmospheric precipitation, tributary/lake mixing, damming regulation, temperature. Both slope intercept evaporative line (δD = 7.88 + 7.96) slightly higher than those Local Meteoric Water catchment (δD= 7.41 6.01). Most river values located below LMWL, thereby implying experienced a certain degree enrichment compositions water. The fluctuations composition (e.g., deuterium excess [d-excess]) middle reaches initial stage operation for Three Gorges Dams (TGD) (2003–2006) due heterogeneous signatures upstream contrast normal (after 2010) characterized maximum largest storage, relatively small variability d-excess was found along because homogenization reservoir with longer residence time complete mixing. tributaries mainstream highlighted contributions Dongting Lake Poyang Lake) efflux mainstream, ranged 21% 85% These findings suggest retention TGD has greatly buffered catchment, improving our understanding complex lake–river interactions future.