Volume 82, September 2015, Pages 66–80
Hydrological performance of a full-scale extensive green roof located in a temperate climate
Highlights
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- We investigated the hydrological performance of a extensive green roof.
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- The roof is a full-scale system installed in 2007 in Leeds, United Kingdom.
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- The monitoring took place over a 20 month period.
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- The green roof was found to effectively retain and detain rainfall during storm events.
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- Retention was found to correspond significantly with rainfall depth, duration, intensity and prior dry weather period.
Abstract
Increasing
recognition is being given to the adoption of green roofs in urban
areas to enhance the local ecosystem. Green roofs may bring several
benefits to urban areas including flood mitigation. However, empirical
evidence from full-scale roofs, especially those that have been
operational for more than several years is limited. This study
investigates the hydrologic performance of a full-scale extensive green
roof in Leeds, UK. Monitoring of the green roof took place over a 20
month period (between 30th June 2012 and 9th February 2014). The results
indicate that the green roof can effectively retain and detain rainfall
from the precipitation events included in the analysis. Retention was
found to correspond significantly with rainfall depth, duration,
intensity and prior dry weather period. Significant differences in
retention values between the summer and winter seasons were also noted.
Regression analysis failed to provide an accurate model to predict green
roof retention as demonstrated by a validation exercise. Further
monitoring of the green roof may reveal stronger relationships between
rainfall characteristics and green roof retention.
Abbreviations
- CSOs, combined sewage overflows;
- SUDS, Sustainable Urban Drainage Systems;
- BMPs, best management practices;
- LIDs, low-impact developments;
- SUWM, Sustainable Urban Water Management Projects;
- ADWP, antecedent dry weather period (h);
- ET, evapotranspiration;
- AWS, automatic weather station;
- NCAS, National Centre for Atmospheric Science;
- TR, total rainfall depth (mm);
- R, total runoff depth (mm);
- PR, retention (%);
- RD, rain duration (h);
- i, rainfall mean intensity (mm/h);
- Rp, rainfall peak intensity (mm/h);
- LG1, lag-time (1) (min);
- LG2, lag-time (2) (min);
- WFD, Water Framework Directive
Keywords
- Urban drainage;
- Storm water management;
- Green roof;
- Retention;
- Urbanisation
- Corresponding author. Tel.:
+44 113 34 31596.
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