城市屋面雨水利用潜力分析——以南京市河西地区某小区为例

城市雨水利用是解决城市水资源短缺和减轻内涝灾害的手段之一。以南京市某小区为例，在分析南京市降雨特征的基础上，利用1〖DK〗∶500地形图资料计算了不同降雨保证率条件下该小区屋面雨水可收集量，分析了雨水收集利用在减轻城市内涝方面的作用，并提出了设置地面蓄水池的4条原则，在此基础上调查分析了该小区设置地面蓄水池的可行性。结果表明:在降雨保证率为50%时，通过屋面年可收集利用的雨量为114 272 1 m3；在日降雨量为500和955 mm（南京市多年平均年最大日降雨量）时，屋面雨水利用可减少214%和112%的地表径流；小区内可设置蓄水池的建筑屋面面积占总屋面面积的55%，其中住宅和其他类建筑中可设置蓄水池的建筑屋面面积比例占77%

ANALYSIS OF POTENTIAL OF URBAN ROOF RAINWATER UTILIZATION ——A CASE STUDY ON A COMMUNITY OF HEXI IN NANJING

Rainwater utilization is a means used to lessen urban water shortage and reduce waterlogging disasters.Based on a large scale of topographic map data(1∶500) and the rainfall data of Nanjing,the volume of available harvesting rainwater in a year with different guaranteed ratio of rainfall and the potential for surface runoff volume reduction are calculated in a community in Nanjing.Then,an analysis of cistern setting feasibility is performed under four principles.The results show that the annual collectable rainwater is approximate 114 272.1 m3 with the guaranteed ratio of rainfall at 50%.And urban waterlogging disasters could be effectively reduced by rainwater harvesting.21.4% and 11.2% of runoff volume could be reduced by roof rainwater utilization in two cases of 50 mm and 95.5 mm respectively(the average annual maximum daily rainfall).The roof area which is suitable to set cisterns is 55% of the total roof area,while the availability rate reached about 77% for residential and the other types of buildings’ roof areas.