Seepage flux and stable isotope data from intact soil columns under natural rainfall events

This dataset contains high-temporal-resolution measurements of seepage flux and stable water isotopes (δ²H and δ¹⁸O) collected from intact soil columns of three different textures (clay loam, silt loam, sandy loam) under natural rainfall events. The experiment was conducted in Chengdu, China, monitoring multiple rainfall events between 2019 and 2021.<br>Data Content:<br><br>Seepage Flux Data: Continuously recorded at 1-second resolution using tipping-bucket flowmeters, providing time-series data of drainage flux (Q, in mm·min⁻¹·cm⁻²) at the base of each soil column.<br><br>Isotope Data: Drainage water samples were collected at 15-30 minute intervals during rainfall events. Stable hydrogen and oxygen isotope compositions were determined by laser-based spectroscopy and are reported relative to the V-SMOW standard.<br><br>Metadata and Parameters: Includes basic soil physical properties, characteristics of monitored rainfall events, and relevant calibration coefficients.<br><br>Key Findings (Data Relevance): The data reveal a robust negative correlation between the isotopic composition of drainage water and the seepage flux (Q). This relationship is pronounced under low-flux conditions (Q &lt; 0.2 mm·min⁻¹·cm⁻²) but diminishes at higher fluxes, exhibiting distinct threshold behavior. This pattern supports the "Interfacial Hydrodynamic Fractionation (IHF)" hypothesis proposed in the associated publication.<br><br>File Description:<br><br>The organization and naming of files in this dataset are closely aligned with the associated academic paper. The paper, entitled "Interfacial hydrodynamic isotope fractionation of infiltrating rainfall in soil pore water is independent of evaporation", has been accepted in principle by the journal Communications Earth &amp; Environment (CEE) and is currently in the proofing stage.<br><br>To facilitate direct tracing and verification of the results presented in the paper, all data files have been created and named to correspond directly and sequentially to the Figures in the main text and the Supplementary Figures and Tables. The specific correspondence can be understood by referencing the structure and content of the aforementioned paper.<br><br>Potential for Reuse:<br>This dataset is valuable for validating and developing soil hydrological models that incorporate non-equilibrium fractionation processes. It contributes to a deeper understanding of soil water movement mechanisms and the ecohydrological separation phenomenon, providing benchmark data for related research.<br>