初期弃流后板房屋面雨水污染物质量浓度衰减规律

为研究初期雨水弃流后不同降雨重现期条件下屋面雨水的污染物质量浓度变化规律，以板房屋面为例，采用3 mm的初期雨水弃流深度，基于暴雨径流管理模型(SWMM)，构建了板房屋面径流模型，在采用雨水收集箱中污染物质量浓度实测值对模型验证后，模拟分析了不同降雨重现期板房屋面雨水的污染物质量浓度衰减规律。结果表明:雨水收集箱中污染物质量浓度衰减过程可分为骤降段、过渡段和稳定段3个阶段；衰减曲线符合一阶衰减指数函数分布，决定系数超过0.93；对于同一种污染物，雨水收集箱中污染物稳定质量浓度随降雨重现期增大而减小。

Attenuation rule of rainwater pollutant concentration on slab roof after split-flow of first flush runoff

In order to study the variation law of the pollutant mass concentration of roof rainwater under different rainfall recurrence periods after split-flow of first flush runoff, taking the slab roof as an example, the 3 mm initial drainage depth was adopted, and the runoff model of slab roof was constructed based on the storm runoff management model. The attenuation law of pollutant concentration of roof rainwater in different rainfall recurrence periods was simulated and analyzed by using the measured pollutant concentration in rainwater collection tank. The results show that the pollutant mass concentration attenuation process includes three periods: rapidly-reducing period, transitional period and stable period, and the curve of pollutant mass concentration attenuation follows a ExpDec1 function with a correlation coefficient of 0. 93. On the same kind of pollutant, the stable pollutant mass concentration in the collection tank decreases with the increase of the rainfall recurrence period.