Study on stable isotope in river water and precipitation in Naqu River basin, Tibetan Plateau

The stable isotope hydrological processes in Naqu River basin,middle of the Tibetan Plateau, was studied based on the observations of δ¹⁸O in both river water and precipitation during the summer in 1998. The fluctuation amplitude of δ¹⁸O is much smaller in river water than in precipitation. The variation of δ¹⁸O in river water is a combined effect of δ¹⁸O in river water,precipitation amount and surface evaporation. The study also found the obvious impact of lake water on stable isotope homogeneity in river water. The difference between the weighted δ¹⁸O in river water and lake water reflects the strong soil surface and lake surface evaporation in the research basin.