Research Article
Spatiotemporal Variation Characteristics of Water Pollution and the Cause of Pollution Formation in a Heavily Polluted River in the Upper Hai River
Table 6
Results of the seasonal Mann–Kendall test and the seasonal Mann–Kendall test of flow-adjusted concentrations.
| Monitoring site | Water quality parameters | SMK test | SMK test of flow-adjusted concentrations | r | a (%) | Trend | R2 | a (%) | Trend |
| G5 | CODCr | −4.300 | 0.14 | Significant downward | 0.150 | 9.27 | Downward | BOD5 | 1.100 | 0.09 | Significant upward | 0.087 | 3.44 | Upward | NH3–N | −1.587 | 0.00 | Significant downward | 0.127 | 0.03 | Significant downward | TP | −0.110 | 0.00 | Significant downward | 0.277 | 0.00 | Significant downward | F− | −0.067 | 0.39 | Significant downward | 0.184 | 17.52 | No trend (trendless) |
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r: decline rate; a: significance level; R2: correlation coefficient of the flow regulation formula. |