兰州市城区不同集流面雨水径流水质分析

Analysis on Rainwater Runoff Quality of Different Catchment Surface in Lanzhou City

针对兰州市水资源匮乏和供需矛盾,为充分利用雨水资源,进一步推行节水型园林绿地建设,本文通过对兰州市区具有代表性的屋面、庭院混凝土路面、机动车道沥青路面雨水径流及蓄雨罐中的雨水水质进行不同时间段化验分析。结果表明:不同集流面雨水径流初期污染物浓度较高,随着降雨历程,浓度有所下降;同一场降雨屋面雨水径流水质最好,其次为混凝土路面径流,二者均可直接用于绿地浇灌,沥青路面雨水径流各阶段固体悬浮物(SS)浓度较高,对园林植物危害较大,不宜直接回用。同时,提出了园林绿地雨水利用的初步建议,为兰州市园林绿地雨水资源的有效利用提供了理论依据。

In view of the scarcity of water resources and imbalance between supply and demand in Lanzhou City, the rainfall quality in rainfall runoff of the typical roof, courtyard pavement, main road surface of motor vehicle of Lanzhou City and rain storage tank was analyzed at different time periods in order to make full use of rainfall resources and promote the construction of water-saving landscaping. The result shows： the pollutant concentration at the initial stage of rainfall runoff in different catchment surface is higher, which will be reduced with rainfall erosion; the water quality of roof runoff is the best for the same rainfall while the courtyard concrete pavement runoff is secondly. Both runoffs could be used for green irrigation directly. Moreover, the concentration of SS in each stage of rainfall runoff of asphalt pavement of motor vehicle is higher, which is harmful to garden plants so that it should not be used directly. Meanwhile, preliminary suggestions on rainfall utilization in garden green space has been proposed in this paper, which provides a theoretical basis for the effective utilization of rainfall resources in Lanzhou garden green space.