Characteristics of stable isotope and hydrochemistry of surface water, and their significance on the Huaibei plain, China

Eighteen river- and two ground- water samples were collected on Huaibei plain. The major ions, and hydrogen and oxygen isotope concentrations were determined, and statistical and other analyses carried out. The results showed that all of the waters are alkaline, with high Total Dissolved Solids (TDS) concentrations. Na⁺ + K⁺, and SO₄²⁻ + HCO₃⁻ are the dominant anionic and cationic species, respectively, and the waters are mainly Na·K-SO₄ and Na·K-HCO₃ types. The δD and δ¹⁸O in river waters ranged from −53.07‰ to −22.07‰ and −6.97‰ to −1.23‰, with average values of −38.30‰ and −4.09‰, respectively. The δD and δ¹⁸O concentrations in groundwater were lower than in the river water samples. The correlation between δD and δ¹⁸O concentrations in the river water can be described by the formula δD = 5.32*δ¹⁸O − 16.54, which can also be considered the local evaporation line. The ionic content and character of the river water is mainly controlled by precipitation, evaporation and carbonate weathering, as deduced from the Gibbs diagram and principal component analyses.