Stable water isotope variations in the alpine Tibetan Plateau: Monitoring and application

Spatial and temporal variations of water isotopes (δ2H and δ18O) are key to hydrological investigation in alpine environment, especially on the impact of climate change on local water resources. Here we present a set of new data obtained through high-frequency monitoring of stable water isotopes (δ2H and δ18O) in natural waters at the southeast part of the Qinghai-Tibet Plateau（QTP）, including precipitation, river water and alpine lake water. The usefulness of alpine lakes in replacing precipitation monitoring in circumstances is emphasized in particular when precipitation monitoring stations are not available. Comparison of results is made between precipitation stations, rivers and the alpine lakes. Role of river samples in determining the elevation gradient on the eastern QTP at different timescales is discussed. Comparison with four different sides of the QTP shows enhanced elevation gradient for the southeast, which is believed to be caused by overlapping monsoon effects in the Southeast of QTP. Rayleigh fractionation models are used to check the hydrological processes involved as well as the reliability of different methods. Our results have been used to calibrate isotope-based paleo-altimetry, to assess groundwater circulation depth, and to evaluate earthquake-induced changes in groundwater and geothermal discharges in the QTP, indicating potential usefulness in these studies in the alpine environments.
The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)