流溪河水质的动态特征

Dynamics of water quality of Liuxihe River

流溪河是广州市的一条重要河流,广州市60%的供水都来自于该河。为探讨流溪河水质的动态特征,沿河设立7个监测断面,于2003年1～12月,每月进行一次采样,对主要水质参数进行了分析。结果表明,上游良口断面全年的水质状况明显好于下游的南岗断面。除pH值外,全年南岗断面的溶解氧、高锰酸盐指数、BOD5、氨氮和总磷均不同程度地超二类水标准,其中以溶解氧超标最为严重,最高值仅为4.94mg·L-1。污染源分布较多的河段,其枯水期的水质要较丰水期差。从良口断面到南岗断面,pH值和溶解氧呈下降趋势,高锰酸盐指数、BOD5、氨氮和总磷呈上升趋势,表明流溪河下游水质较差,有机污染较严重。

Liuxihe River was one of the most important rivers in Guangzhou and about 60% drinking water of Guangzhou city was supplied by this river. In order to investigate the water quality of Liuxihe River, seven sampling sites were set along the river and water quality parameters were analyzed monthly in 2003. The water quality status in the upstream site Liangkou was much better than that in the downstream site Nangang throughout the year. Most of the parameters in Nangang had exceeded the water quality standard Ⅱ including DO, CODMn, BOD5, NH3-N and TP. Among these parameters, DO was the worst item and the maximum value of it was only 4.94mgL. Water quality was worse in dry season than that in flood season. From Liangkou to Nangang, the pH and DO declined gradually while CODMn, BOD5, NH3-N, TP increased. The results showed that water quality in the downstream of Liuxihe River had been polluted by organic matter.