This study presents the results of tests conducted in 2009 and 2010 on experimental sites installed on the roof of the Science and Education Building of the Wroclaw University of Environmental and Life Sciences. The aim of the analysis was to determine the retention capacity of green roofs and the runoff delays and peak runoff reduction during rainfall recorded in Wroclaw conditions.
The research shows that green roofs allow to reduce the volume of runoff stormwater in comparison to conventional roofs, that they delay the runoff in time and influence the reduction of the maximum runoff intensity, and thus may limit the impact of stormwater on the stormwater drainage and combined sewage systems.
The article shows the need to take into account the principles of sustainable development in the field of the revitalization of space, and point out green roofs as a tool in this process. It is presented in the light of the green city concept, and the criteria of the European Green City Index. The article shows the ecological, social and economic benefits of green roofs (starting from the retrieval of green areas in the urbanized space, the reduction of heat island effects, up to the integration function of green roofs), which is illustrated by a few case studies of applying green roofs within revitalization projects. The article indicates also legal incentives, as well as programs directed to the development of green roofs around the world, pointing out a range of factors to consider also for Polish cities.