模糊综合评价法在广州市水质分析评价中的应用

Analysis of the Comprehensive Evaluation of Water Quality in Guangzhou Based on the Fuzzy Comprehensive Evaluation Method

针对广州市境内2002—2016年中数据完整分布合理的12个站点,对境内增江流域、流溪河流域以及广州市中心网河区近15 a各个站点的水质监测数据进行了统计分析,探讨了全流域内水体污染物浓度变化的时空变异特征。结果表明:(1)21个水质检测项目中影响水质的主要因子分别是溶解氧、氨氮、高锰酸盐指数、硫酸盐、氯化物、五日生化需氧量、硝酸盐;(2)街口、增城和麒麟咀三个断面的水质相对较好,基本维持在Ⅱ类水;黄埔断面水质较差,虽经过治理后有明显好转,但大多数年份仍为Ⅳ-Ⅴ类水;其他断面水质基本维持在Ⅲ-Ⅳ类;(3)2005年和2011年是突变年,多个断面水质综合评价出现好转并持续良好水质至今。广州市未来需要继续严格实施水环境综合治理,落实最严格水资源管理制度。

For the 12 sites with complete data and reasonable distributions within the territory of Guangzhou City from 2002 to 2016,statistical analysis is made to the water quality monitoring data from every site of the basins of Zengjiang,Liuxi River,and the city s central river areas in the past 15 years.The characteristics of temporal and spatial variation on the water pollutant concentration in the whole basin are discussed,providing the basis for the city s water pollutant control,water environment protection,and ecological rehabilitation.The results show that:①Using principal component analysis method to analyze 21 principal components which affect water quality in the test,defined in The Standards of Surface Water Environment Quality(GB 3838-2002),based on weight values,the principal factors that affect water qualities are DO,NH 3-N,MnO-4,SO 2-4,Cl-,BOD 5,NO-3 by screening;②Applying the fuzzy comprehensive evaluation method to the evaluation of the annual water quality data from the 12 sections,in comparison with single factor evaluation method,the former method is more likely to reflect the reality;The results calculated by fuzzy comprehensive evaluation method shows that the water quality evaluation grade of Jiekou,Zengcheng and Qilingzui sites have been relatively well maintained in level 2;Huangpu site s water quality has been worst in these 15 years,although after treatments it has improved significantly,but it still keep staying above level 4.Other sections of water quality remained in class 3-4;③Implementing Mann-Kendall test method to the analysis of trend behind the water pollutant concentration variation and the exploration on the pattern of the water pollutant concentration s time variation,research shows years 2005 and 2011 are break years,sustainable improvements in the water quality concentration can be observed until now,it is necessary for Guangzhou to maintain strict water environment governance.