Hydrochemistry and Entropy-Based Groundwater Quality Assessment in the Suining Area, Southwestern China

Yunhui Zhang,Changli Wei,Yong Xiao,Xiao Li,Xun Huang,Qiuming Pei,Limao Qin,Ming Luo,Xubo Gao

doi:10.1155/2021/5591892

Abstract

Groundwater is an essential resource for sustainable development, whose quality is significant for human health. In the present study, twenty-eight groundwater samples were collected from domestic tube wells and public water supply wells in the Suining area, southwestern China. The integration of statistical analysis, correlations of ions, geomodelling, and entropy-weighted water quality index (EWQI) was carried out to clarify the hydrochemistry and groundwater quality in the study area. By the statistical analysis, the cations followed the concentration order as Ca2+> Na+> Mg2+> K+, while anions’ concentrations were HCO3− > SO42− > Cl− > NO3− > F−. Piper trilinear diagram showed the hydrochemical type was characterized as Ca-HCO3. Correlations of ions and geomodelling revealed the concentrations of major ions were mainly determined by carbonate dissolution and ion exchange process, and NO3− concentrations were controlled by agriculture activities. EWQI computation demonstrated that most of the groundwater samples possessed EWQI values higher than 100. Therefore, groundwater quality is lower than the permissible limit of the World Health Organization (WHO), suitable for drinking purposes in the Suining area. Our study provides vital knowledge for groundwater management in the Suining and other similar areas.

Highlights

Groundwater is the basic and vital resource for humans living around the world
A statistical approach is used to analyse the general scope, which is shown in the Box-Whisker diagram [15]. e Piper trilinear diagram can present the water type clearly [16]. e mechanism for groundwater chemistry is mainly determined by natural processes and anthropogenic activities [17,18,19]
General Characteristics of Groundwater Chemistry. e statistical results of hydrochemical parameters are presented in Table 2 and Figure 3, which were compared with the standard limits of the World Health Organization (WHO). e pH values varied from 7.1 to 8.4, indicating neutral to slightly alkaline character and permissible for drinking purpose

Summary

Introduction

Groundwater is the basic and vital resource for humans living around the world. groundwater quality is deteriorating due to the rapid development of industrialization and urbanization, great growth of population, and excessive use of fertilizers [1,2,3]. Comprehensive investigations of groundwater chemistry, mechanism analysis, and quality evolution can provide robust information for groundwater protection, which have been carried out globally [9,10,11]. Understanding groundwater chemistry is the critical fundament for mechanism analysis and quality evolution [12,13,14]. E Piper trilinear diagram can present the water type clearly [16]. E mechanism for groundwater chemistry is mainly determined by natural processes and anthropogenic activities [17,18,19]. Natural processes generally consist of water-rock interaction, precipitation, and evaporation. Gibbs plots are regarded as the classic approach to distinguish the natural governing factors affecting groundwater chemistry [20]. Assessment of groundwater quality is a hot topic for numerous researchers. The traditional water quality index (WQI) was introduced to evaluate groundwater quality

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Conclusion