APPLICATION OF MAJOR ION CONCENTRATIONS FOR THE PREDICTION OF STABLE ISOTOPIC COMPOSITION IN SURFACE WATER

Kai Chen,Linhua Sun

doi:10.3846/jeelm.2021.14221

Abstract

The δ2H and δ18O values in water bodies are essential to the management of water resources because of the ability to insight into hydrological processes. In this study, we have measured and analyzed the major ions (Na+, K+, Ca2+, Mg2+, Cl–, SO24– and HCO–3 ) and stable H-O isotopes (δ2H and δ18O) for fifteen surface water samples collected from the Xinbian River in Suzhou, northern Anhui Province, China. The results show that all of the water samples are classified to be Na-HCO3 type, and the mean values of δ2H and δ18O are –42.93‰ and –5.36‰, respectively. Gibbs diagram and the relationship between δ2H and δ18O indicate that both water chemistry and stable isotopes in river water are mainly controlled by evaporation. Correlation analysis reveals that a significant correlation between major ions and δ18O. Predictors (K+, SO24– and HCO–3 ) have been selected by optimal subset regression analysis were used to model the δ18O values in the river water. Moreover, the residuals of the model were normally distributed and values between –0.2‰ to 0.2‰ for most water samples, suggesting a strong relationship between the observed and predicted δ18O values.

Highlights

Water is the most important resource for human survival and social development
Previous study found that the relationship between δ2H and δ18O tends to deviate from the GWML in different regions due to a variety of factors, including climate, altitude, latitude, and etc., and the national meteoric water lines (NMWL) were often used to explore precipitation patterns in different countries (Dansgaard, 1964; Gat, 1996)
Over the last few decades, several studies have been carried out based on the analyses of water stable isotopes, and these findings have provided important guidance for the regional management of water resources (Jeff, 2015; Sun et al, 2016; Tran et al, 2019; Wet et al, 2020)

Summary

Introduction

In recent years, water pollution in many areas has become more seriously as a result of human activities, such as households, agriculture and industry (Wang & Yang, 2016; Alam et al, 2020; Singh et al, 2020) Under this situation, the stable isotopes have gained more attention from researchers because it can be used to understand the hydrological processes in different watersheds (Kumar et al, 2019), the relationships between different water bodies (Qian et al, 2013; Zhang et al, 2015), water quality assessment (Brooks et al, 2014) and sources of water recharge (Qian et al, 2014; Prada et al, 2016; Cao et al, 2018; Kuang et al, 2019). Over the last few decades, several studies have been carried out based on the analyses of water stable isotopes, and these findings have provided important guidance for the regional management of water resources (Jeff, 2015; Sun et al, 2016; Tran et al, 2019; Wet et al, 2020)

Methods

Results

Conclusion