NAME OF PRESENTER: KINGA OWCZAREK (SRI)
TITLE
Study on Rainwater Retention Effect of Extensive Green Roofs
KEY WORDS
Green roof, Stormwater management, Retention, Runoff
1.1 INTRODUCTION
Green roofs are roofs on which vegetation is intentionally grown. The installation of a green
roof has the potential to bring environmental, economical and aesthetical benefits such as
reduction and delay of storm water runoff, improvement of the storm water runoff quality,
mitigation of the heat island effect, air quality improvement, enhancement of biodiversity,
energy savings, and provision of recreational and agricultural spaces, if carefully designed to
specific climate conditions.
This work concentrates on reduction of the storm water runoff (rainwater retention) effect
of extensive green roofs.
1.2 OVERVIEW OF METHODOLOGY
The investigation of the retention effect is based on continuous monitoring program of nine
different green roof configurations (on site experiment) and five different green roof designs
(laboratory experiment). Researched green roofs are constructed varying parameters such as
depth of the substrate and drainage layer as well as vegetation and material type.
1.3 PRELIMINARY FINDINGS
The results show that the extensive green roofs can reduce runoff by retaining more
rainwater daily, monthly, yearly or per an individual rain event in comparison to conventional
roof. Rainfall time and intensity as well as substrate moisture content influence significantly
rainwater retention. Storm water runoff reduction is greater for the roofs of greater substrate
depth. Further analyses of data series are in progress.