Temporal and spatial variations of δ18O in precipitation of the Yarlung Zangbo River Basin.

This paper reveals the temporal and spatial variations of stable isotope in precipitation of the Yarlung Zangbo River Basin based on the variations of δ¹⁸O in precipitation at four stations (Lhaze, Nugesha, Yangcun and Nuxia) in 2005. The results show that δ¹⁸O of precipitation has distinct seasonal changes in the Yarlung Zangbo River Basin. The higher value of δ¹⁸O occurs in spring prior to monsoon precipitation, and the lower value occurs during monsoon precipitation. From the spatial variations, with the altitude-effect and rainout process during moisture transport along the Yarlung Zangbo River Valley, ¹⁸O of precipitation is gradually depleted. Thus, δ¹⁸O of precipitation decreases gradually from the downstream to the upstream, and the lapse rate of δ¹⁸O in precipitation is approximately 0.34‰/100m and 0.7‰/100km for the two reasons. During monsoon precipitation, spatial variation of δ¹⁸O in precipitation is dominated by the amount effect in the large scale synoptic condition. [ABSTRACT FROM AUTHOR]