201. Hydrologic Performance of an Extensive Green Roof under Intense Rain Events: Results from a Rain-Chamber Simulation
- Author
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Jacopo Gaspari, Elena Giacomello, and Giacomello E., Gaspari J.
- Subjects
green roof ,010504 meteorology & atmospheric sciences ,Geography, Planning and Development ,Green roof ,lcsh:TJ807-830 ,lcsh:Renewable energy sources ,010501 environmental sciences ,Management, Monitoring, Policy and Law ,01 natural sciences ,soil sealing ,NBS-nature based solutions ,intense rain event ,water management ,sustainably built environment ,rain chamber ,medicine ,water retention ,water detention ,runoff coefficient ,rain peak ,peak discharge ,cumulative curve ,lcsh:Environmental sciences ,0105 earth and related environmental sciences ,Hydrology ,lcsh:GE1-350 ,Renewable Energy, Sustainability and the Environment ,lcsh:Environmental effects of industries and plants ,Water storage ,Substrate (marine biology) ,Water retention ,Runoff coefficient ,lcsh:TD194-195 ,Environmental science ,medicine.symptom ,Scale (map) ,Surface runoff ,Intensity (heat transfer) - Abstract
The water storage capacity of a green roof generates several benefits for the building conterminous environment. The hydrologic performance is conventionally expressed by the runoff coefficient, according to international standards and guidelines. The runoff coefficient is a dimensionless number and defines the water retention performance over a long period. At the scale of single rain events, characterized by varying intensity and duration, the reaction of the green roof is scarcely investigated. The purpose of this study is to highlight how an extensive green roof—having a supposed minimum water performance, compared to an intensive one—responds to real and repetitive rain events, simulated in a rain chamber with controlled rain and runoff data. The experiment provides, through cumulative curve graphs, the behavior of the green roof sample during four rainy days. The simulated rain events are based on a statistical study (summarized in the paper) of 25 years of rain data for a specific location in North Italy characterized by an average rain/year of 1100 mm. The results prove the active response of the substrate, although thin and mineral, and quick draining, in terms of water retention and detention during intense rain events. The study raises questions about how to better express the water performance of green roofs.
- Published
- 2021