三峡水库蓄水前后重庆段整体水质变化分析

随着三峡水库的形成和不同水位的蓄水，水环境发生了很大的变化。通过对三峡水库重庆段2003～2009年主要代表监测断面水质监测数据的统计分析，采用单因子评价方法对蓄水前后整体水质进行评价，以各月水质类别占全年比例的变化来反映水质变化特征。结果表明：不考虑粪大肠菌群，三峡库区重庆江段总体水质良好，各个监测断面水质类别大多为Ⅲ类（含优于Ⅲ类水），少数断面个别年月总磷、高锰酸盐指数和石油类超标较严重。干流2003~2009年Ⅲ类水质类别所占比例为58.9%~80.56％，且比重呈上升趋势，变化幅度平缓；支流2004~2009年Ⅲ类所占比例为80.3％~96.96％，年变化趋势平缓。三峡水库蓄水6 a来，库区江段总体水质呈向好趋势。

Analysis on general variation of water quality in Chongqing reach after impoundment of Three Gorges Reservoir

Through statistical analysis on water quality monitoring data of main monitored sections in the Three Gorges reservoir from 2003 to 2009,the general water quality of the reservoir before and after impoundment is evaluated with single factor method and the change characteristics of water quality is reflected through the ratio of monthly water quality classification to annual water quality classification.The analysis results show that if fecal coliform is not considered,in general,the water quality in Chongqi...