城区屋面径流水质特征与初期径流量研究

Research on Water Quality Characteristics of Urban Roof Runoff and Initial Runoff Amount

研究城区屋面径流水质变化特征和初期径流量,可为有效利用城市雨水、控制非点源污染等提供依据。对新乡市2010年城区屋面3场降雨～径流的水文水质过程进行采样分析,结果表明:①屋面径流系数在0.92～0.98之间,径流形态与降雨过程线类似,二者波动幅度相对较小;②各指标标准差率呈SS>COD>DO>pH值的趋势,这与各自含量变化过程的指向性一致;③径流中主要污染物SS、COD变化趋势基本一致,即随着降雨历时的持续其含量逐渐降低,并趋于一个稳定值;④径流中SS与COD之间的相关性较好,而DO与其之间的相关性较差;⑤场次降雨屋面初期径流量为1～3mm的降雨量或前15～20min的径流量。

The Study on the water quality characteristics of urban roof runoff and initial runoff amount can provide the basis for effectively using urban rainfall and controlling non-point source pollution, and so on. The hydrological and water quality process of three rainfall events on urban roof was sampling and analyzing in 2010 in Xinxiang City, Henan Province. The result showed that： ①The runoff coefficient of urban roof was 0. 9240.98, the shape runoff curve was similar with the rainfall process, both of them fluctuate lightly.②The standard deviation rate of water quality indicator was in the order of SS〉COD〉DO〉pH, which is consistent with directivity of these indicators＇ concentration variation.③Along with the duration of rainfall, the variation trend of main pollutant index SS, COD in runoff was similar and tends to a steady value. ④The correlation between SS and COD was good in the runoff, but that between DO and these pollutants was bad. ⑤The initial runoff amount of urban roof was equivalent to 1-3 mm rainfall or run- off in former 15-20 rain.