[Hydrochemical Characteristics, Controlling Factors and Water Quality Evaluation of Shallow Groundwater in Tan-Lu Fault Zone （Anhui Section）].

To study the hydrochemical characteristics, controlling factors, and groundwater quality of the Tan-Lu fault zone (Anhui section), 86 groundwater samples were taken from the areas surrounding the Tan-Lu fault zone (Anhui section), which included the Jianghuai Wavy Plain, the Yanjiang Hill Plain, and the Dabie Mountains in western Anhui. Descriptive statistics, Piper diagram, Gibbs diagram, ion ratio analysis, saturation index, chloride-alkalinity index, and entropy weight water quality index (EWQI) were used to comprehensively study the hydrochemical characteristics and controlling factors of groundwater and to evaluate its quality. The results showed that the shallow groundwater in the Tan-Lu fault zone (Anhui section) was weakly alkaline, with dominant anions and cations of HCO, Ca and Na, respectively, and the hydrochemical types were mainly HCO-Ca·Mg and HCO-Na·Ca.

[Hydrochemical Characteristics and Control Factors of Surface Water and Groundwater in Huainan Coal Mine Area].

To clarify the hydrochemical characteristics and control factors of surface and underground water in Huainan mining area, 115 groups of groundwater and 30 groups of surface water samples were collected, and the hydrogeochemical characteristics of surface water and groundwater in Huainan mining area were analyzed. Additionally, the hydrochemistry evolution law was discussed by comprehensively using mathematical statistics, the Piper triangular diagram, Gibbs diagram, mineral stability field diagram, and ion ratio relationship, etc. The results showed that the groundwater and surface water in the study area were weakly alkaline, the dominant anion was HCO, and the dominant cations were Ca and Na.