东莞不同下垫面降雨径流污染输移规律研究

摘要

基于同沙水库集水区代表性功能区降雨径流水量、水质的监测,评价分析了东莞降雨径流污染输出过程、污染状况及初始冲刷效应等污染特征,根据径流污染负荷分配规律探讨了初期雨水截留参考标准,并应用主成分分析得出影响降雨径流污染负荷的主要因素.研究结果表明,同沙水库集水区降雨径流污染浓度值接近典型生活污水的浓度值,污染负荷较高,对同沙水库水质有严重的影响.降雨径流污染输出有较显著的时间特征且受降雨特征因素的影响,存在中等的初期冲刷效应.影响污染负荷的主因子是最大雨强、雨前干期长度、不透水率.采用FF40作为初期径流截留参考值,截留初期40％的径流比截留整场降雨径流更为经济、有效.%Based on runoff water quantity and quality monitoring of representative of different land use in Tongsha Reservoir catchment, pollution output process, pollution situation and first flush effect in Dongguan city were analyzed. According to distribution regulations of runoff pollutant loads, the first flush interception reference criteria had been discussed. And principal component analysis was applied to conclude main factors influencing on runoff pollutant loads. The results eventually showed that the runoff pollution concentration of the reservoir catchment was close to the concentration value of typical sewage, pollutant loads were high, resulting in a serious effect to the water quality of the reservoir. Rainfall runoff output had significant features of time, and the common first flush had occurred. The main factors of pollution loads include maximum rainfall intensity, antecedent dry days and waterproof rate. Using FF40 as the reference value of early period runoff retention, intercepting the early 40% of runoff volume would be more effective and economical than intercepting the whole.