城市屋面降雨冲刷污染物变化模型模拟研究

Simulation Model of Rainfall Wash-off Pollutant on Urban Roof

城市屋面降雨径流污染是受纳水体质量恶化的主要影响因子。以典型屋面作为汇水单元,开展天然降雨情况下雨水径流水文水质过程监测试验,水质指标包括SS、COD、TN。利用雨水径流产流负荷替代降雨强度校正了传统冲刷模型,研究有效降雨深度与径流水质之间的相关函数关系,构建了雨水径流污染物浓度变化模型,对相关参数进行求解。模型模拟的SS、COD、TN的浓度变化过程精度较高,纳什效率系数均在0.87以上。表明模型的实用性较好,可为城市雨水资源高效利用、面源污染控制技术与措施制定、海绵城市建设等提供依据。

Rainfall runoff pollution from urban roof is one of the major influencing factors for the deterioration of receiving water body. With the typical urban roof as the catchment unit,in this research we conducted series of experiments to monitor the hydrology and water quality change of rainwater-runoff under natural rainfall conditions. Water quality monitoring indicators included SS,COD,TN. Using the rainfall runoff generation load instead of rainfall intensity to correct the traditional erosion model,we analyzed the function relationship between runoff water quality and effective rainfall depth,and developed the rainfall-runoff pollutants concentration change model and calibrated the relevant parameters. The accuracy of SS,COD and TN concentration variation process was higher in model simulation,and the Nash efficiency coefficients were over 0. 87. It turned out the model is practical which can provide evidence for effectively utilizing urban rainfall resources,non-point source pollution of management technologies and measures,sponge city construction and so on.