基于单项指数法和模糊综合评价法对松花江吉林市段水质的评价

Application of Single Index Method and Fuzzy Comprehensive Method in Water Quality Evaluation of Jilin City Section of Songhua River

在松花江吉林市段布设了14个监测断面,对各监测断面BOD5、CODMn、氨氮、总磷及溶解氧等水质因子进行枯水期、平水期、丰水期的水质监测,运用单项指数法和模糊综合评价法对监测结果进行评价。单项指数评价结果表明枯水期水质为Ⅳ类,BOD5、CODMn为主要污染因子;平水期为Ⅴ类,BOD5为首要污染因子;丰水期水质Ⅳ类,首要污染物为BOD5、CODMn。模糊综合评价结果表明枯水期仅有F、I、L三个监测断面水质超过Ⅲ类水标准,且均隶属于Ⅳ类;平水期出现I、L两个隶属于Ⅳ类水的监测断面和一个隶属于Ⅴ类水的监测断面J;丰水期水质均达到Ⅲ类以上水质标准。对比两种评价方法,模糊综合评价法更适于松花江吉林市段的水质评价。

This study set 14 monitoring sections on Jilin City section of Songhua River to monitor water quality factors such as BOD5, CODMn, NH3 - N, TP, and DO, etc. of every section in the dry season, wet season and medium water season. Furthermore, fuzzy evaluation method and single index method was applied to evaluate the monitoring results. The evaluation results of single index method indicated that the water quality in dry season was Ⅳ class with BOD5 and CODMn as key pollution factors. The water quality in medium water season was V class with BOD5 as key pollution factor. The water quality in wet season was Ⅳ class with BODs and CODMn as key pollution factors. The fuzzy comprehensive evaluation results show that the water quality of only three monitoring sections （ F, I, L） were aboveⅢ class. They all belong to Ⅳ class in the dry season. In the medium water season, two monitoring section （I, L） above Ⅳ class and J monitoring section is at V class, beyond that all are overmatch Ⅲ class. Fuzzy comprehensive evaluation method is more suitable for evaluating the water quality of Jilin City section of Songhua River.