ABSTRACT

We examined the performance of ecoroofs with different substrate depths (75 mm, 125 mm) as well as a conventional roof using rainfall and runoff data collected between 2014 and 2017 in Portland, Oregon, USA. The two ecoroof plots exhibited similar effectiveness in retaining storm runoff across all storm size categories, and both ecoroofs retained the most stormwater during small storms. Retention ratio (RR) was highest during the dry season and the lowest in the early and middle of the wet season. RR was also positively associated with antecedent dry weather period (ADWP) with significantly higher retention when ADWP was longer than 3 days. Together, event storm size and ADWP explain approximately 50% of RR variation in middle and late-wet seasons. Overall, these findings indicate that environmental parameters such as storm frequency and size had a greater influence on greenroof performance than an additional 50 mm of substrate.

摘要

我们使用2014年至2017年在美国俄勒冈州波特兰市收集的降雨和径流数据，研究了不同基材深度（75 mm，125 mm）的生态屋顶以及常规屋顶的性能。这两个生态屋面在保持所有暴风雨大小类别的雨水径流方面显示出相似的效果，并且两个生态屋面在小暴风雨期间都保留了最多的雨水。保留率（RR）在干旱季节最高，而在雨季的早期和中期最低。当ADWP超过3天时，RR也与干旱前期（ADWP）呈正相关，且保留率明显更高。事件风暴的大小和ADWP共同解释了中湿季和后期湿季的RR变化的大约50％。总体，