Li Jun-Sheng, Yin Hai-Wei, Kong Fan-Hua, Chen Jia-Yu, Deng Jin-Ling
International Institute for Earth System Sciences, Nanjing University, Nanjing 210023, China.
School of Architecture and Urban Planning, Nanjing University, Nanjing 210093, China.
Huan Jing Ke Xue. 2019 Apr 8;40(4):1803-1810. doi: 10.13227/j.hjkx.201809050.
Increasingly frequent urban waterlogging disasters, which are mainly caused by the increase in impervious surfaces due to rapid urbanization, have attracted public attention. Green roofs are conducive to increasing the urban pervious surface area to control sources of runoff, which has great significance for the ecological environment. This study uses the green roof of the administrative building of Jinling Primary School in Nanjing as the study area. 76 rainfall-runoff events collected over 17 months (2016-06-2017-10) were used to calculate the comprehensive runoff control ability and factors influencing the green roof in the context of the site scale. Based on life cycle assessment theory, the benefits of stormwater regulation over its 30-year life cycle were quantitatively evaluated. The results show that:① The average retention of the green roof was 62.7%, which could have a significant impact on runoff and peak flow, reducing the runoff time and delaying the flood peak. ② The green roof has a strong ability to retain runoff during small and medium rainfall; however, this ability becomes low when the retention capacity is saturated or not fully recovered, even in small rainfall-runoff events. ③ The main factors affecting the retention ability of the green roof are the total rainfall, rainfall intensity, and water content of the growth substrate soil. ④ The green roof has great economic benefits, with a construction cost of about 12.51 yuan·m and a return on investment of 0.41. The results of this study can provide an important scientific basis and decision-making reference for the planning and construction of green roofs and the promotion of related policies.
日益频繁的城市内涝灾害主要是由快速城市化导致的不透水表面增加引起的，已引起公众关注。绿色屋顶有利于增加城市透水表面积以控制径流源头，对生态环境具有重要意义。本研究以南京金陵小学行政楼的绿色屋顶为研究区域。利用2016年6月至2017年10月17个月内收集的76次降雨径流事件，在场地尺度背景下计算绿色屋顶的综合径流控制能力及影响因素。基于生命周期评估理论，对其30年生命周期内的雨水调节效益进行了定量评估。结果表明：①绿色屋顶的平均截留率为62.7%，对径流和峰值流量有显著影响，可减少径流时间并延迟洪峰。②绿色屋顶在中小降雨期间具有较强的截留径流能力；然而，即使在小降雨径流事件中，当截留能力饱和或未完全恢复时，这种能力也会变低。③影响绿色屋顶截留能力的主要因素是总降雨量、降雨强度和生长基质土壤的含水量。④绿色屋顶具有很大的经济效益，建设成本约为12.51元·平方米，投资回报率为0.41。本研究结果可为绿色屋顶的规划建设及相关政策的推广提供重要的科学依据和决策参考。
