Water quality assessment and pollution evaluation of surface water sources：The case of Weishan and Luoma Lakes, Xuzhou, Jiangsu Province, China

Water pollution is a pressing concern in China as well as in other countries around the world. Despite escalating the water quality issues associated with the water sources of Xuzhou, Jiangsu Province, China—namely Weishan and Luoma Lakes—a dearth of scientific and systematic guidance regarding water environmental management remains. This study investigated the water quality and potential pollution sources of Weishan and Luoma Lakes through hydrochemical analysis, correlation analysis (CA), principal component analysis (PCA), as well as analyses of the Water Quality Index (WQI) and pollution evaluation index (PEI). Results showed that the average values of some components, such as turbidity, total dissolved solids (TDS), total nitrogen (TN), total hardness (TH), and alkalinity (ALK), were higher than the standard limits. The CA results revealed heterogeneity in the sources and pathways of the pollutants and ions. PCA was used to identify five key water quality indicators for Weishan and Luoma Lakes, explaining a cumulative variance of 85.26–86.64% and 83.56–85.64%, respectively. In Weishan Lake, anthropogenic and industrial sources were the primary contributors to water pollution, whereas in Luoma Lake, anthropogenic and natural sources were the primary pollution source, followed by agricultural sources. In general, the WQI and PEI values indicated that the water quality in Weishan Lake and Luoma Lake was classified as “good” during the study period, despite the deterioration of water quality in both lakes. Overall, implementing a robust management plan for maintaining the aquatic environment in these two lake areas is necessary.