Abstract: In order to understand the pollution situation of the rivers in the main urban area of Chongqing and provide some data basis and support for their future remediation work, eight secondary rivers in the main urban area of Chongqing were selected for water quality assessment with comprehensive water quality identification index method, taking CODMn, TP, TN, NH3-N, and DO as assessment indicators. The research results show that: the water quality of Huaxi River, Xiaojia River, Kuxi River, Huangxi River and Panxi River is within or superior to class V water quality standard of surface water in GB3838-2002, whereas that of the Qingshui Stream, Gailan Stream and Taohua Stream is inferior to class V, with poor overall water quality, but not yet to black smelly level. Moreover, it is confirmed that the river pollution is mainly caused by the eutrophication of TN, NH3-N and TP, in which the rivers with TN exceeding the water quality standard in the effluent functional area account for 100%, the rivers with NH3-N exceeding the standard account for 50%, and the rivers with TP exceeding the standard account for 37.5%.

Key words: environment engineering, water quality assessment, integrated water quality indentification index, secondary rivers of the Yangtze River

摘要： 为了解重庆市主城区河流的污染情况并为其今后的整治工作提供一定的数据依据及支撑，选取重庆市主城区内的8条次级河流，以CODMn、TP、TN、NH3-N、DO作为评价指标，采用综合水质标识指数法进行评价。研究结果表明：花溪河、肖家河、苦溪河、黄溪河和盘溪河水质均达到或优于GB 3838-2002中地表水Ⅴ类水质标准，而清水溪、溉澜溪和桃花溪为劣Ⅴ类水质水体，总体水质较差，但尚未形成黑臭。此外，研究证实河流污染主要是由TN、NH3-N和TP超标导致的富营养化，其中TN超出水功能区水质标准的河流总数比为100%，NH3-N超标的河流占比为50%，TP超标的河流占比为37.5%。

关键词: 环境工程, 水质评价, 综合水质标识指数法, 长江次级河流