Table 3 Descriptive statistics of water quality variables in Huzhou city between 2001 and 2007.
Mean | Minimum | Maximum | Standard Deviation | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Parameters | Low water | Normal water | Flood | Total | Low water | Normal water | Flood | Total | Low water | Normal water | Flood | Total | Low water | Normal water | Flood | Total |
pH | 7.56 | 7.48 | 7.47 | 7.50 | 6.02 | 6.38 | 6.26 | 6.02 | 8.95 | 8.9 | 8.87 | 8.95 | 0.37 | 0.35 | 0.40 | 0.25 |
DO | 8.04 | 7.24 | 5.16 | 6.84 | 0.25 | 0.55 | 0.51 | 0.25 | 13.53 | 15.2 | 12.54 | 15.2 | 2.88 | 2.66 | 1.96 | 1.72 |
CODMn | 4.53 | 4.24 | 4.38 | 4.38 | 0.41 | 0.33 | 0.48 | 0.33 | 13.5 | 13.1 | 15.8 | 15.8 | 1.61 | 1.69 | 1.62 | 0.73 |
BOD | 3.25 | 3.29 | 2.95 | 3.17 | 0.23 | 0 | 0.16 | 0 | 19.1 | 16.3 | 23.2 | 23.2 | 2.02 | 1.95 | 1.92 | 1.68 |
NH3-N | 1.11 | 1.18 | 0.93 | 1.08 | 0.01 | 0.01 | 0.01 | 0.01 | 16.8 | 8.91 | 8.79 | 8.91 | 1.62 | 1.53 | 1.17 | 0.56 |
ArOH | 0.00 1 | 0.001 | 0.001 | 0.001 | 0.001 | 0.001 | 0.001 | 0.001 | 0.008 | 0.007 | 0.003 | 0.008 | 0.00 | 0.00 | 0.00 | 0.00 |
Petroleum | 0.10 | 0.09 | 0.07 | 0.09 | 0.005 | 0.01 | 0.01 | 0.005 | 1.52 | 1.88 | 0.862 | 1.88 | 0.14 | 0.15 | 0.10 | 0.05 |
DTP | 0.16 | 0.16 | 0.16 | 0.16 | 0.004 | 0.004 | 0.003 | 0.003 | 1.29 | 1.6 | 2.24 | 2.24 | 0.18 | 0.21 | 0.21 | 0.13 |
TN | 3.57 | 4.24 | 3.10 | 3.61 | 0.36 | 0.49 | 0.27 | 0.27 | 17.2 | 13.7 | 10.7 | 17.2 | 2.73 | 2.48 | 1.82 | 0.76 |
