Water Stable Isotope Dataset of the Siling Co Basin, 2025

Description

This dataset contains hydrogen and oxygen stable isotope compositions (δD and δ¹⁸O) of different water bodies collected from the Siling Co Basin, a large endorheic lake basin in the central Tibetan Plateau. The dataset includes δ¹⁸O and δD values of precipitation, river water, groundwater, glacier meltwater, and lake water, together with relevant sampling information such as sample type and sampling date. These samples were collected to characterize the spatial and temporal variability of water isotopes across the basin and to support the identification of hydrological connections among precipitation input, glacier meltwater, river inflow, groundwater recharge, and lake water balance. The isotope dataset provides the observational basis for evaluating below-cloud evaporation of precipitation, partitioning runoff sources in glacierized and non-glacierized catchments, and estimating lake evaporation relative to inflow using isotope mass balance approaches. It can be used to improve understanding of water cycling processes and lake expansion mechanisms in high-elevation endorheic basins under a warming and wetting climate.

Steps to reproduce

1. Establish a stable isotope monitoring network across the Siling Co Basin covering the major hydrological components, including precipitation, lake water, river water, glacier meltwater, and groundwater. 2. Collect precipitation samples from two sampling sites located at Xainza County and the Tanggula Mountains, representing the southern and northern source regions of the basin. 3. Collect lake water samples from seven lake sampling sites. Conduct daily sampling at representative sites in the eastern and northern parts of Siling Co using automatic samplers, and collect samples from the remaining lake sites at intervals of 20–30 days. 4. Collect river water samples from ten river sampling sites. Conduct daily high-frequency sampling at representative glacier-fed and lake-connected rivers, and collect samples from the remaining rivers at intervals of 20–30 days. 5. Collect glacier meltwater samples at approximately 2-day intervals from the terminus of the Dongkemadi Glacier in the Tanggula Mountains. 6. Collect groundwater samples from five sampling sites distributed along an elevational gradient to characterize spatial variations in groundwater isotopic composition. 7. Record sample type, sampling site, and sampling date for each water sample during field sampling. 8. Analyze stable water isotope ratios, including δD and δ¹⁸O, using a liquid-water isotope analyzer. 9. Analyze each sample six times and use the mean value of the final four measurements to reduce analytical uncertainty associated with instrumental memory effects. 10. Report isotope results relative to the appropriate reference standard and conduct quality control based on analytical precision. In this dataset, measurement precision was ±0.2‰ for δ¹⁸O and ±0.6‰ for δD.

Institutions

• Institute of Mountain Hazards and Environment

  Sichuan, Chengdu
• Northwest Institute of Eco-Environment and Resources

  Gansu, Lanzhou
• University of Chinese Academy of Sciences

  Beijing, Beijing

Categories

Funders

• the Science and Technology Projects of Xizang Autonomous Region, China

  Grant ID: XZ202501ZY0030 and XZ202601ZD0014
• the National Natural Science Foundation of China

  Grant ID: 42401156 and 42330512
• the Key Laboratory of Mountain Hazards and Engineering Resilience, Chinese Academy of Sciences

  Grant ID: KLMHER-TO4
• the State Key Laboratory of Cryospheric Science and Frozen Soil Engineering

  Grant ID: CSFSE-TZ-2414

Licence