title: Quantitative analysis on the urban flood mitigation effect by the extensive green roof system.
abstract: Extensive green-roof systems are expected to have a synergetic effect in mitigating urban runoff, decreasing temperature and supplying water to a building. Mitigation of runoff through rainwater retention requires the effective design of a green-roof catchment. This study identified how to improve building runoff mitigation through quantitative analysis of an extensive green-roof system. Quantitative analysis of green-roof runoff characteristics indicated that the extensive green roof has a high water-retaining capacity response to rainfall of less than 20 mm/h. As the rainfall intensity increased, the water-retaining capacity decreased. The catchment efficiency of an extensive green roof ranged from 0.44 to 0.52, indicating reduced runoff comparing with efficiency of 0.9 for a concrete roof. Therefore, extensive green roofs are an effective storm water best-management practice and the proposed parameters can be applied to an algorithm for rainwater-harvesting tank design.
authors.affiliation: KIST (Korea Institute of Science and Technology), Gangneung Institute, Gangnueng 210-340, South Korea. juyounglee@snu.ac.kr
authors.forename: J Y
authors.initials: JY
authors.lastname: Lee
authors.forename: H J
authors.initials: HJ
authors.lastname: Moon
authors.forename: T I
authors.initials: TI
authors.lastname: Kim
authors.forename: H W
authors.initials: HW
authors.lastname: Kim
authors.forename: M Y
authors.initials: MY
authors.lastname: Han
mesh_terms: D002947:Cities; D003247:Conservation of Natural Resources / Q000379:methods*; D004323:Drainage, Sanitary; D052918:Environmental Restoration and Remediation / Q000379:methods*; D055868:Floods; D006798:Housing; D011891:Rain; D013696:Temperature; D014872:Water Movements; D014881:Water Supply
keywords: BMP; Catchment efficient; Extensive green roof; Mitigate urban runoff; Water retaining capacity