Groundwater quality, health risk, and major influencing factors in the lower Beiluo River watershed of northwest China

Abstract

Groundwater is the major water source for irrigation and domestic purposes in and around Beiluo River watershed, Guanzhong Basin of northwestern China. To provide a scientific basis for sustainable groundwater development, 25 groundwater samples in the lower Beiluo River watershed were collected and analyzed. The overall groundwater quality was assessed through entropy-weighted water quality index (EWQI) and US Salinity Laboratory (USSL) diagrams. The non-carcinogenic human health risks caused by fluoride through the oral and dermal pathways were also assessed. Then the influence of driving factors on groundwater quality was qualitatively discussed based on GIS technology, and the degree of influence of each factor on groundwater quality was calculated quantitatively through Geodetector. The results show that the hydrogeochemical type of groundwater in the lower Beiluo River watershed is dominated by SO₄·Cl-Na type, followed by HCO₃-Na type, HCO₃-Ca·Mg type, and SO₄·Cl-Ca·Mg type. Groundwater quality is good to very poor, which indicates the groundwater of some areas is unsuitable for drinking. In addition, groundwater in some parts of the study area is inappropriate for direct irrigation due to high salinity which can result in soil salinization. Residents of this area are facing health risks induced by drinking high-fluorine groundwater and children in study area are at higher health risk than adults. Geodetector calculation indicates that the explanatory power index q of major influencing factors is ranked as follows: population > soil types > land use types > elevation > topography, indicating that population is the main potential influencing factor on groundwater quality in this study.

Keywords:

• Groundwater quality
• entropy weight
• water quality index
• non-carcinogenic risks
• Geodetector

Acknowledgments

The authors are grateful for the useful and constructive comments from the editors and reviewers, which have helped the authors to improve the quality of the manuscript. Students who participated in the field investigation are acknowledged for their valuable work during the investigation.

Disclosure statement

The authors declare that they have no conflict of interest.

Additional information

Funding

The authors are grateful for the financial support received from the Scientific Innovation Practice Project of Postgraduates of Chang’an University (300103703061).