Research Article
Hydrogeochemical Evolution and Control Mechanism of Underground Multiaquifer System in Coal Mine Area
Table 1
Sample indexes-descriptive statistics.
| Parameters | The Cenozoic aquifer | The Permian aquifer | The carboniferous aquifer | Min | Max | Mean | Skewness | Min | Max | Mean | Skewness | Min | Max | Mean | Skewness |
| K++Na+ (mg/L) | 111 | 202.47 | 152.71 | 0.26 | 578.6 | 1550.27 | 1036.94 | 0.05 | 168.65 | 813.98 | 398.6 | 0.48 | Ca2+ (mg/L) | 79.55 | 124.73 | 99.89 | 0.24 | 1.13 | 63.15 | 25.59 | 0.63 | 2.42 | 447.56 | 202.17 | 0.09 | Mg2+ (mg/L) | 28.81 | 81.12 | 54.93 | 0.09 | 1.17 | 38.66 | 13.73 | 0.8 | 5.53 | 323.69 | 121.44 | 1.09 | Cl− (mg/L) | 91.98 | 144.67 | 115.43 | 0.15 | 56.46 | 354.16 | 171.91 | 0.82 | 82.98 | 188.91 | 143.39 | -0.37 | SO42− (mg/L) | 207.06 | 417.26 | 283.62 | 1.01 | 833.2 | 2524.69 | 1668.09 | 0.45 | 1001.36 | 1770.6 | 1404.92 | -0.16 | HCO3− (mg/L) | 279.83 | 541.86 | 419.79 | -0.35 | 164.21 | 692.17 | 435.72 | -0.14 | 129.91 | 340.89 | 240.28 | 0.29 | TDS (mg/L) | 899.23 | 1239.45 | 1058.24 | 0.22 | 2023.48 | 5005.01 | 3371.35 | 0.32 | 2020.85 | 3088.47 | 2534.47 | 0.02 | PH | 7.3 | 8.4 | 7.57 | 2.39 | 7.79 | 8.32 | 7.94 | 1.96 | 7.1 | 8.3 | 7.68 | -0.6 |
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