崇明岛主要河道水质评价及时空变化特征

Water quality evaluation and temporal-spatial variation characteristics of main rivers in Chongming Eco-Island,Shanghai City

地表水是崇明岛重要的环境要素之一,为了解崇明生态岛十年建设以来主要河道水质变化情况,基于崇明岛主要河道2010~2020年间5个主要评估年份的监测数据,采用单因子水质标识指数法、综合污染指数法、主成分分析法等,对崇明岛主要河道水质时空变化特征进行分析。结果表明:①崇明生态岛十年建设期间,主要河道水质维持在Ⅱ~Ⅲ类,TP潜在超标性强。②水质主要影响因子的贡献程度从大到小排序为:高锰酸盐指数(I_(Mn))、五日生化需氧量(BOD_(5))、化学需氧量(COD)、总氮(TN)、氨氮(NH_(3)-N)、总磷(TP)、溶解氧(DO)。③水质随时间变化趋势无显著意义,岛域南部河道水质优于北部。基于分析评价结果,建议后期进一步加强水系沟通,加强农业面源污染治理,实施分区管理等。

Surface water is one of the important environmental elements of Chongming Eco-Island,Shanghai City.In order to analyze the characteristics of main rivers in Chongming Eco-Island in past decade,based on the monitoring data of 5 major assessment years from 2010 to 2020,we use single-factor water quality labeling index method,comprehensive pollution index method,and principal component analysis,etc.,to analyze the water quality characteristics and the trend changes of main rivers in Chongming Eco-Island.Results showed that:①During the ten-year construction of the Chongming Eco-Island,the water quality of main rivers remained at categoryⅡ-Ⅲ,and TP had a potential to exceed the standard.②The contribution of the main influencing factors of water quality was ranked as follows:I_(Mn)、BOD_(5)、COD、TN、NH_(3)-N、TP、DO.③The trend of water quality changes over time had no significant meaning,and the water quality of the southern section was better than that of the northern section.Based on the analysis results,it was recommended that the water system communication should be further improved,the treatment of agricultural non-point source pollution should be strengthened,and the partition management should be implemented.