Global Soil Water Stable Isotope Dataset

Soil water is a key medium linking the atmosphere, vegetation, and groundwater systems, and its stable isotopes (2H and 18O) are powerful tracers of ecohydrological processes. However, historical soil-water isotope observations remain fragmented, lack structurally harmonized formatting, and are unevenly distributed in space and time, which severely constrains cross-regional and global-scale research. To address these gaps, we compiled and structurally harmonized a comprehensive global dataset of soil-water stable isotopes spanning 1975 to 2024. The dataset integrates primary in-situ measurements, literature-extracted records, and open-repository data, comprising a total of 27,455 records from 463 observation sites across 37 countries on six continents. To facilitate comparative analysis, the records are classified into standardized profile intervals representing shallow (0-10 cm), active-root (10-40 cm), mid-depth (40-100 cm), and deep (>100 cm) soil layers, coupled with essential geospatial and temporal metadata. This globally representative dataset provides a robust empirical foundation for evaluating terrestrial water cycling, calibrating regional hydrological models, tracing ecosystem water-use strategies, and addressing hydroclimatic challenges under global environmental change.