Basic statistics of the chosen chemical parameters are listed in Table 1. In general, the dominant cation in groundwater was with median value of 340.1 mg/L, and the dominant anion was Na+ with median value of 153.1 mg/L. The coefficients of variance (CV) is the ratio of standard deviation to the mean value of a variable. CV shows the extent of variability in relation to the mean of variables, and is advantageous in allowing comparisons among variables that differ in units and ranges. Among these variables, showed the highest CV, which is probably affected by point contamination, whereas demonstrated the smallest CVs indicating the similar formation background of the groundwater in the study area. Correlation analysis results are shown in Table 2. EC was significantly correlated with most variables, with the highest correlation coefficient of 0.803 computed for Na+. Mg2+, Ca2+, and Sr2+ were highly and positively correlated, among which the correlation coefficient between Mg2+ and Sr2+ was greater than 0.9, possibly indicating their common source. No significant correlation was observed between Mg2+ and Sr2+, and Na+, which suggests that Na+ had a different source from the other major cations. As for the anions, were significantly correlated, whereas which is usually assumed to be a product of mineral weathering, was significantly and negatively correlated with Cl, and no obvious relationship was found between . Beyond certain limits, and UV254 are often regarded as indicators of anthropogenic pollution (Fenech et al. 2012); these two parameters were significantly and positively correlated in the study, with a correlation coefficient greater than 0.5.

Table 1

Descriptive statistics of hydrochemical parameters

ParametersMinimumMaximumMedianStandard deviationCoefficient of variance/%
EC, μs/cm 924.0 4,580.0 1,661.5 758.7 41.86
, mg/L 203.3 559.2 340.1 81.6 23.35
, mg/L 12.8 298.3 95.0 58.3 58.26
Cl, mg/L 27.9 418.2 98.0 75.8 63.50
, mg/L 0.3 222.0 2.4 40.6 219.97
F, mg/L 0.232 4.372 0.649 0.636 83.68
Ca2+, mg/L 30.6 173.9 83.4 33.1 37.71
Mg2+, mg/L 32.3 213.9 72.8 31.9 40.86
Na+, mg/L 37.8 578.9 153.1 117.8 65.70
K+, mg/L 0.396 6.983 1.69 1.320 66.10
SiO2, mg/L 8.9 21.4 17.31 3.2 19.08
Sr2+, mg/L 0.7 4.3 1.6 0.6 34.41
UV254 0.005 0.051 0.018 0.012 56.69
ParametersMinimumMaximumMedianStandard deviationCoefficient of variance/%
EC, μs/cm 924.0 4,580.0 1,661.5 758.7 41.86
, mg/L 203.3 559.2 340.1 81.6 23.35
, mg/L 12.8 298.3 95.0 58.3 58.26
Cl, mg/L 27.9 418.2 98.0 75.8 63.50
, mg/L 0.3 222.0 2.4 40.6 219.97
F, mg/L 0.232 4.372 0.649 0.636 83.68
Ca2+, mg/L 30.6 173.9 83.4 33.1 37.71
Mg2+, mg/L 32.3 213.9 72.8 31.9 40.86
Na+, mg/L 37.8 578.9 153.1 117.8 65.70
K+, mg/L 0.396 6.983 1.69 1.320 66.10
SiO2, mg/L 8.9 21.4 17.31 3.2 19.08
Sr2+, mg/L 0.7 4.3 1.6 0.6 34.41
UV254 0.005 0.051 0.018 0.012 56.69
Table 2

Results of bivariate correlation analysis

ECFClSO2−4HCO3Ca2+K+Mg2+Na+SiO2Sr2+NO3UV254
EC 1.000
F −0.564** 1.000
Cl 0.611** −0.340* 1.000
0.680** −0.337* 0.521** 1.000
0.127 0.142 −0.409** −0.121 1.000
0.464** −0.807** 0.286* 0.297* −0.216 1.000
0.110 −0.371** 0.315* 0.157 −0.165 0.240 1.000
0.610** −0.427** 0.234 0.358* 0.231 0.543** 0.082 1.000
0.803** −0.209 0.449** 0.523** 0.283* −0.008 −0.001 0.208 1.000
−0.618** 0.275 −0.498** −0.512** 0.054 −0.112 −0.119 −0.069 −0.670** 1.000
0.454** −0.400** 0.247 0.198 0.119 0.554** 0.126 0.878** 0.034 0.014 1.000
0.557** −0.627** 0.395** 0.396** −0.139 0.564** 0.346* 0.391** 0.280* −0.567** 0.283* 1.000
UV254 0.542** −0.617** 0.431** 0.503** −0.143 0.469** 0.380** 0.287* 0.349* −0.541** 0.161 0.652** 1.000
ECFClSO2−4HCO3Ca2+K+Mg2+Na+SiO2Sr2+NO3UV254
EC 1.000
F −0.564** 1.000
Cl 0.611** −0.340* 1.000
0.680** −0.337* 0.521** 1.000
0.127 0.142 −0.409** −0.121 1.000
0.464** −0.807** 0.286* 0.297* −0.216 1.000
0.110 −0.371** 0.315* 0.157 −0.165 0.240 1.000
0.610** −0.427** 0.234 0.358* 0.231 0.543** 0.082 1.000
0.803** −0.209 0.449** 0.523** 0.283* −0.008 −0.001 0.208 1.000
−0.618** 0.275 −0.498** −0.512** 0.054 −0.112 −0.119 −0.069 −0.670** 1.000
0.454** −0.400** 0.247 0.198 0.119 0.554** 0.126 0.878** 0.034 0.014 1.000
0.557** −0.627** 0.395** 0.396** −0.139 0.564** 0.346* 0.391** 0.280* −0.567** 0.283* 1.000
UV254 0.542** −0.617** 0.431** 0.503** −0.143 0.469** 0.380** 0.287* 0.349* −0.541** 0.161 0.652** 1.000

*Correlation is significant at the 0.05 level (two-tailed).

**Correlation is significant at the 0.01 level (two-tailed).

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