双台子河流域综合水质评价方法的对比研究

本研究利用双台子河2011年枯、丰、平水期的22个水文监测断面数据,并借助主成份分析法,确定主要污染因子和超标断面。分别采用综合标识指数、单因子、模糊评判、灰色关联四种评价法,选取DO、COD、NH3-N、TP、TN、BOD 6个评价因子,对河流水污染特性进行综合评价与分析。结果表明:以Bartlett球度检验,主成份因子负荷值较高的NH3-N、TP、BOD因子,累积方差贡献率91.97%,主要污染因子;超标断面的污染因子判别应考虑周边污染源的类型和河流上游的排放物浓度。模糊评判、灰色关联评价结果中均没有劣V类,两者的水质类别累积频率均在V类到达100%;考虑到单因子法在同一水质类别中不能判定多项因子共同对水体的综合影响,本文采用标识指数法为最佳评价方法。从枯、丰、平水期的劣V类和V类断面比重分析,枯水期>平水期>丰水期。从劣V类和V类数量与分布来看,盘锦市辖区控制单元的污染程度,比大洼县和盘山县污染较重。

Comparison of Water Quality Assessment Methods in Shuangtaizi River

The 22 monitoring sections were sited at Shuangtaiz River, and were monitored during low water period, high wa- ter - level period, and normal water period in 2011. The major pollution factors and quality distribution characteristics were distin- guished based on 6 evaluated factors by means of multivariate statistical analysis. The comprehensive analysis and evaluation of water pollution distribution and characteristics were contrasted with DO, COD, NH3 - N, TP, TN, BOD factors by identification index, single factor, fuzzy evaluation and gray correlation evaluation methods. These results show that 3 principal component fac- tors inspection are higher than others in Bartlett test, and this cumulative contribution rate is up to 82. 3%, therefore, the main pollution factors are NH3 -N, TP and BOD. These pollution sections exceed the standard provisions should be considered sur- rounding sources type and emission concentration in the upper reaches of the river. There is Class V in the classification results e- valuated by fuzzy evaluation, gray correlation, meanwhile, both of the cumulative frequency for water quality category reaches to 100% in Class V. Considering the synthesis effects of many factors, the paper identification index is used to assess water quality classification as the best evaluation method. At last, by analysis different period and proportion of lower Class V and Class V sec- tions, water quality in low water period is the worst and water quality in water - level period is bad. The quantity and distribution of the lower Class V and Class V in Panjin City control unit more seriously polluted than the Dawa unit and Panshan unit.