长江下游取水口水源水质变化特征分析

Characteristics Analysis of Water Quality Variations in the Downstream of Yangtze River

利用单因子指数法和内梅罗指数法相结合的方法，对2006-2013年长江下游仪征市取水口水源水质监测数据进行了分析。结果表明，（1）由于水温、流量、泥沙及污染物含量等要素的季节性变化，单因子指数及内梅罗指数的年内变化具有一定的规律性，但可能是由于三峡水库以丰补枯的调节作用，年内水质变化趋于平稳；（2）年际间溶解铁含量呈明显减小趋势，特别是近两年水质均基本符合饮用水源水水质标准的要求，但是六价铬含量呈增加明显趋势，需要采用措施控制含铬废水的排放。

Based on the water quality data from 2006 to 2013, the paper discussed the characteristics and causes of water quality variations of the Yangtze Rive at Yizheng intake with the single factor index method and Nemerow index method. The results showed that, （1） the intra-annual changes of the single factor index and Nemerow index possessed obvious regularity because of the seasonal related factors＇ changes, such as water temperature, flow, sediment and pollutant concentration, but those changes were small as the runoff regulation of Three Gorges Reservoir improved water quality during the dry season; （2） Inter-annual changes of water quality showed a gradually improving tendency because of observably decreasing of iron concentration, especially in the last two years, the water quality basically met the quality standard for drinking water source. But the hexavalent chromium concentration was increasing gradually, therefore it was urgent to adopt measures to control the discharge of chromium the wastewater contained