Roof Runoff Control by Using the Green Blue Roof and Blue Roof in the Urban Area

This study addresses the role of green (vegetated) blue roof and blue roof in the stomwater management in urban area. Green-blue roof and blue roof were constructed at two different location in Seoul, Korea. These two roofs can retain, delay the rainfall runoff and can also reduce the peak flow which are very helpful to avoid the flash flooding in urban areas. This study evaluated performance for rainfall runoff management of the Blue roof and Green blue roof comparing monitoring data measured at two LID facilities and control roof. The data used for this research were collected during the actual rainfall events of more than 30 mm/hr and 60 mm/hr rainfall intensity in July and September 2014 at green blue roof and blue roof respectively. Through this process, the runoff and peak flow reduction on the roofs have been analyzed. Result indicated the runoff outflows reduction were 1.55 l/s to 0.45 l/s in blue roof and 0.3 l/s to 0.1 l/s in green blue roof respectively. It is also indicated that the green blue roof are more effective in case of big storm events, whereas the blue roof are less expansive for small runoff control.