绿化屋面的水文水质特征分析

通过人工搭建绿化屋面装置,重点研究了绿化屋面的径流削减率、产流过程和出水水质3个方面。结果表明,绿化屋面的径流削减率符合一定的阶段性计算公式;绿化屋面产流过程中的径流总量、前期削减量和后期削减量三者与基质层高度呈现不同的线性相关性;绿化屋面能够有效降低雨水中的总氮浓度和COD浓度,但氨氮浓度和总磷浓度有所升高;最后,综合水文和水质两方面,建议绿化屋面基质层高度范围是10—20cm。

Characters of Hydrology and Water Quality of Green Roof

Green roof is capable of significantly reducing rainwater volume and purifying rainwater quality. It has become one of the important strategies to solve urban floods. This study investigated the ratio of runoff retention, effluent process and effluent water quality by building pilot scale facilities. Results from the experiment confirmed that the ratio of runoff retention is accordance with a certain periodic formula; the total runoff volume, the amount of previous reduction and later reduction have different linear correlations with the thickness of substrate layer; and green roof is capable of significantly reducing the concentrations of TN and COD, but the concentrations of NH₄-N and TP in runoff from green roof are higher relatively. Finally, this study recommends that the optimal range of the thickness of substrate layer is 10-20 cm by integrating the two aspects of hydrology and water quality.