城区河涌水质随径流量变化的时间过程分析研究

Research on the Time Course of River Water Quality with Runoff in Urban Area

河涌水质在降雨期间出现恶化是水环境治理的难题,对其在降雨期间的变化规律进行研究有重要意义。选取广州市猎德涌广深铁路渠箱片区进行研究,采集降雨期河涌水样,检测各项指标数据,通过结合流量数据和无量纲曲线法建立径流-污染关系。结果表明,猎德涌不仅在前期受初始冲刷影响,还在中后期出现管渠冲刷污染,后者造成的污染程度是前者的2~5倍;COD、TN初始冲刷效应明显,TP、SS的情况较轻,但在管渠冲刷污染中4种污染物均比较突出;初始冲刷与管渠冲刷污染主要受降雨特征与水流条件变化的影响。

Deterioration of river water quality during rainfall is a difficult problem for water environment treatment,and it is of great significance to study its change rules during rainfall.Taking the canal area of Guangzhou-Shenzhen Railway in Guangzhou Liede River as the research object,this paper collects river water samples during the rainfall period,detects various index data,and establishes runoff-pollution relationship by combining flow data and dimensionless curve method.The results show that the Liede River is not only affected by first flush in the early stage but also polluted by pipe scouring in the middle and late stages.The pollution caused by the latter is 2~5 times that of the former;COD and TN at first flush is serious,and TP and SS are less,but the four pollutants in pipe scouring pollution are more prominent;pipe scouring pollution and first flush are affected by changes in rainfall characteristics and water flow conditions.