Water Stable Isotope Dataset of the Siling Co Basin, 2025

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.