Evaluation of Drinking Water Quality Using the Water Quality Index (WQI), the Synthetic Pollution Index (SPI) and Geospatial Tools in Lianhuashan District, China

Due to the impact of human agricultural production and climate and environmental changes, the applicability of groundwater for drinking purposes has attracted widespread attention. In order to quantify the hydrochemical characteristics of groundwater in Lianhuashan and evaluate its suitability for assessing water for drinking purposes, 71 groundwater samples were collected and analyzed. The results show that groundwater in aquifers in the study area is weakly alkaline. The abundance is in the order HCO3->Cl->SO42- for anions, and Ca2+>Na+>Mg2+ for cations. Groundwater chemical types were dominated by HCO3-Ca, HCO3-Ca center dot Mg, and HCO3-Ca center dot Na. The Factor analysis, and PCA analysis show that ion exchange, and rock weathering are the main reasons affecting the water chemical composition in Lianhuashan. The analysis of water samples based on the WQI model revealed that about 69.09%, 25.45%, 1.81%, and 3.63% of the water samples were excellent, good, very poor, and unsuitable for drinking purposes, respectively. The analysis of water samples based on the SPI model showed that 18.30%, 66.19%, 7.04%, and 8.45% of the water samples were suitable, slightly polluted, moderately polluted, and highly polluted, respectively. The spatial distribution maps of the water quality index and the synthetic pollution index show that most of the groundwater resources in the study area are clean and suitable for drinking, despite the risks in the north and southwest of the study area.