IAHR, founded in 1935, is a worldwide independent member-based organisation of engineers and water specialists working in fields related to the hydro-environmental sciences and their practical application. Activities range from river and maritime hydraulics to water resources development and eco-hydraulics, through to ice engineering, hydroinformatics, and hydraulic machinery.
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You are here : eLibrary : IAHR World Congress Proceedings : 36th Congress - The Hague (2015) ALL CONTENT : Flood risk management and adaptation : Comparison of green roof performance in stormwater mitigation
Comparison of green roof performance in stormwater mitigation
The impervious surfaces in urban areas often increase overland flow and river discharge leading to flooding issues.
Green roof, being one low impact development technique, can potentially facilitate stormwater management and advert
flooding problems. Although there are a number of studies examining the hydrologic behaviour of green roof, they are
often limited to the monitoring periods which may not involve extreme rainfall events. They are also specific to the
rainfall conditions of the study areas, making it difficult to transfer the knowledge to other countries. This study uses
numerical models to quantify the hydrological behaviour of green roof and to examine the effectiveness of green roof in
stormwater management. In particularly, it compares its performance in extreme rainfall events of different countries. A
one-dimensional variably-saturated flow model is used. The calibrated model is subjected to the rainfall conditions of a
few cities (i.e., Hong Kong, Singapore, Nagoya and London) of two-year return period. The reduction and the delay of
the peak discharge, and the fraction of water retained are compared. The green roof performances (e.g., peak reduction,
rainfall retained) vary due to the differences in rainfall characteristics (e.g., temporal pattern, total rainfall volume). The
modeling results from different countries allow a consistent comparison, generating insights that might facilitate the
transfer of results across countries. Overall, this study improves our understanding of hydrological behaviour of green
roofs for stormwater management, in particularly benefiting the interpretation of green roof hydrological studies
performed at rainfall conditions different from the area of interests.
File Size : 454,782 bytes
File Type : Adobe Acrobat Document
Chapter : IAHR World Congress Proceedings
Category : 36th Congress - The Hague (2015) ALL CONTENT
Article : Flood risk management and adaptation
Date Published : 13/08/2015
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