Impacts of green roofs on storm water management and urban climate

几个世纪以来，绿色屋顶一直被用于隔离建筑物和美化城市环境。欧洲国家，尤其是德国，已经在现代建筑中采用了绿色屋顶，这有助于提高人们对绿色屋顶许多潜在好处的认识。绿色屋顶已被证明：有效地减少和过滤雨水，从而减轻城市下水道系统的负担；提供隔热和降低屋顶表面温度，从而减少建筑能源负荷和相关的碳排放；并通过减少引起屋顶损坏的温度波动来延长屋顶的寿命。考虑到绿色建筑可以减轻雨水径流的负面影响，减少供暖和制冷需求，由于我们的极端气候，在加拿大使用绿色屋顶可能会被证明是非常有益的。然而，在北美城市环境中，绿色屋顶的实施仍然没有得到充分利用，部分原因是缺乏适合气候的绿色屋顶设计指南。在这个项目中，绿色屋顶的使用将在加拿大的三个城市进行研究，形成全国各地经历的天气条件的代表性样本。这包括寒冷的冬季和干燥的夏季（卡尔加里，AB），中间的冬季和潮湿的夏季（伦敦，ON），温和的冬季和高降水事件（哈利法克斯，NS）。在每个场地，将使用不同的植被类型、屋顶坡度和生长介质深度，并测量重要参数，以评估这些变量对绿色屋顶性能的影响。该项目将支持六名暑期学生、六名研究生和一名博士后建造绿色屋顶，收集必要的数据，表征加拿大环境下的绿色屋顶性能，并开发一个数值模型来优化绿色屋顶设计。这项研究将提供有价值的工具，以采取更严格的方法进行绿色屋顶设计，并量化加拿大使用绿色屋顶的好处。因此，这项研究将导致加拿大更多地使用绿色屋顶，从而产生许多经济、环境和健康效益，并改善加拿大的城市环境。

Green roofs have been used for centuries to insulate buildings and beautifyurban environments. European countries, especiallyGermany, have adopted green roofs for use in modern buildings, helping raise awareness of their manypotential benefits. Green roofs have been shown to: effectivelyreduce and filter stormwater therebydecreasing the burden on urban sewer systems; providing insulation and lowering roof surface temperature leading to a decrease in building energyload and associated carbon emissions; and extending the life of a roof bydecreasing the temperature fluctuations which cause roof damage. Given that green buildings can mitigate against the negative impacts of storm water runoff and reduce the heating and cooling demands, use of green roofs in Canada might prove extremelybeneficial due to our climate extremes. However, the implementation of green roofs in North American urban environments remains underused, in part due to a lack of climate appropriate green roof design guidelines. Inthis project, the use of green roofs will be studied in three cities in Canada, forming a representative sampleof weather conditions experienced across the country. This includes cold winters and drysummers (Calgary, AB), intermediate winters and humid summers (London, ON), and mild winters and high precipitation events (Halifax, NS). At each site, different vegetation types, roof slopes, and growth medium depth will be used and important parameters will be measured to assess the impact of these variables on green roof performance. The project will support six summer students, six graduate students, and one postdoctoral fellow to construct the green roofs, collect the necessarydata, characterize green roof performance in Canadian environments, and develop a numerical model to optimize green roof design. This studywill provide valuable tools to take a morerigorous approach to green roof design and quantifythe benefits of green roof use in Canada. As a result, this studywill lead to an increased use of green roofs in Canada, resulting in manyeconomic, environmental, and health benefits and the improvement of Canadian urban environments.