Geochemical constraints on persistent river-driven vertical groundwater recharge
Description
This dataset contains water chemistry and isotope data for river water and regional groundwater from typical suspended river areas in the lower reaches of the Yellow River.
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Steps to reproduce
Two field sampling campaigns were carried out in November 2021 (dry season) and July 2022 (wet season). Three sampling transects were arranged perpendicular to the Yellow River channel, along which a total of 37 water samples were collected, including river water, groundwater, and precipitation. During the dry-season campaign (November 2021), 10 samples were obtained—9 from shallow groundwater (Q1–Q9; depths <100 m) and 1 from Yellow River water (S3). During the wet-season campaign (July 2022), 27 samples were collected, including 2 river water samples (S1–S2), 1 precipitation sample (P1), and 24 groundwater samples (G1–G24). The groundwater samples comprised 9 shallow (25–100 m), 12 intermediate (100–220 m), and 3 deep aquifer samples (300–400 m). To improve the representativeness of deep groundwater isotope data, supplementary measurements were incorporated from a previous study on surface water-groundwater interactions in the northern Henan Plain (Yang, 2018). These included five groundwater samples collected between March and May 2017 along the Yellow River in Yuanyang County—two from intermediate aquifers (Z1, W5) and three from deep aquifers (W4, Z2–Z3)—all containing stable hydrogen-oxygen and tritium isotope data. Field parameters such as groundwater temperature, air temperature, and water table depth were recorded on site. Water samples for hydrochemical analysis were collected in 2.5 L and 500 mL high-density polyethylene (HDPE) bottles for complete and simplified analyses, respectively. Samples for stable isotope (δD, δ18O) and tritium (3H) measurements were collected in 500 mL and 60 mL HDPE bottles, sealed tightly to prevent evaporation, and stored for laboratory analysis. Hydrochemical analyses were conducted at the Rock and Mineral Testing Center of Henan Province – Water Quality Testing Center. Major cations (K+, Na+, Ca2+, Mg2+) and anions (HCO3-, SO42-, Cl-, CO32-) were measured using an iCAP 7400 Radial ICP-OES (Thermo Fisher Scientific) and a Dionex AQUION IC ion chromatograph. Stable hydrogen and oxygen isotopic compositions were determined using a Picarro L2140-i Liquid Water Analyzer at Beijing Taisi Te Testing Technology Co., Ltd., employing wavelength-scanned cavity ring-down spectroscopy (WS-CRDS). Isotope ratios of D and 18O are reported in δ notation (‰) relative to Vienna Standard Mean Ocean Water (V-SMOW). Tritium measurements were carried out at at the Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, using an ultra-low background liquid scintillation counter. The analytical precision is 0.5 TU, with a detection limit of 0.5 TU.
Institutions
- Zhengzhou University