Quantifying Evapotranspiration Rates for New Zealand Green Roofs
Publication: Journal of Hydrologic Engineering
Volume 15, Issue 6
Abstract
Green roofs are an emerging storm-water management tool that has predominantly been analyzed for runoff volume reduction and peak flow mitigation. Little research has been completed on evapotranspiration (ET) in green roofs. Sedum mexicanum (Mexican stonecrop) and Disphyma australe (New Zealand iceplant) in a New Zealand designed, pumice- and zeolite-based substrate were analyzed to determine daily and hourly ET rates under both water-abundant and drought-stressed conditions. Water loss, and thus storage recovery of the substrate, was greatest in the first 9 days. Transpiration by S. mexicanum contributed up to 48% of total ET (2.19 mm/day) and D. australe contributed up to 47% of total ET (2.21 mm/day). After the initial rate of rapid water loss, plants conserved water and ET was not significantly different from evaporation from unplanted substrate. S. mexicanum had a greater ability to conserve water and thus a greater longevity of life than D. australe under harsh drought conditions.
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Acknowledgments
The research team thanks the Auckland Regional Council for project funding and Earl Shaver for overall support. Additional thanks go to the University of Auckland postgraduate researcher Chunsen Tang and Landcare Research technicians Chris Winks and John Dando for their continued assistance.
References
Antlfinger, A. E., and Dunn, E. L. (1979). “Seasonal patterns of CO2 and water vapor exchange of three salt marsh succulents.” Oecologia, 43(3), 249–260.
Berghage, R. D., et al. (2007). Quantifying evaporation and transpirational water losses from green roofs and green roof media capacity for neutralizing acid rain, Penn State University, University Park, Pa.
Center for the Study of Carbon Dioxide and Global Change. (2009). CO2 science, Center for the Study of Carbon Dioxide and Global Change, Tempe, Ariz.
Dando, J. (2008). Moisture release characteristics of field zeolite mix, Landcare Research, Palmerston North, New Zealand.
Del Barrio, E. (1998). “Analysis of the green roofs cooling potential in buildings.” Energy Build., 27(2), 179–193.
Durhman, A. K. (2005). “Evaluation of crassulacean species for extensive green roof applications.” MS thesis, Michigan State Univ., East Lansing, Mich.
Fassman, E. A., and Simcock, R. (2007). Extensive green roof design for new and retrofit application in the Auckland Region, Univ. of Auckland, Auckland, New Zealand.
FLL. (2002). “Guidelines for the planning, execution, and upkeep of green-roof sites.” Rep. No. 3253115, Forschungsgesellschaft Landschaftsentwicklung Landschaftsbau, Bonn, Germany.
Hilten, R. N., Lawrence, T. M., and Tollner, E. W. (2008). “Modeling storm-water runoff from green roofs with HYDRUS-1D.” J. Hydrol., 358(3–4), 288–293.
Jarrett, A. R., Hunt, W. F., and Berghage, R. D. (2007). “Evaluating a spreadsheet model to predict green roof stormwater management.” Proc., 2nd National Low Impact Development Conf., Environmental and Water Resources Institute of ASCE, Wilmington, N.C.
Lazzarin, R. M., Castellotti, F., and Busato, F. (2005). “Experimental measurements and numerical modelling of a green roof.” Energy Build., 37(12), 1260–1267.
Levallius, J. (2005). “Green roofs on municipal buildings in Lund—Modeling potential environmental benefits.” MS thesis, Lund Univ., Lund, Sweden.
Munsell Colour Division. (1972). Munsell colour charts for plant tissues, Munsell Colour Company, Baltimore.
Neales, T. F., Fraser, M. S., and Roksandic, Z. (1983). “Carbon isotope composition of the halophyte Disphyma clavellatum (Haw.) Chinnock (Aizoaceae), as affected by salinity.” Aust. J. Plant Physiol., 10(5), 437–444.
NIWA Science. (2000a). Mean monthly rainfall, National Institute of Water and Atmospheric Research, Auckland, New Zealand.
NIWA Science. (2000b). Summary climate information for selected New Zealand locations, National Institute of Water and Atmospheric Research, Auckland, New Zealand.
NIWA Science. (2007). The climate of New Zealand: Northern New Zealand, National Institute of Water and Atmospheric Research, Auckland, New Zealand.
Rezaei, F., and Jarrett, A. R. (2006). “Measure and predict evapotranspiration rate from green roof plant species.” Proc., Penn State College of Engineering Research Symp., Penn State Univ., University Park, Pa.
Rezaei, F., Jarrett, A. R., Berghage, R. D., and Beattie, D. J. (2005). “Evapotranspiration rates from extensive green roof plant species.” Proc., 2005 ASAE Annual Int. Meeting, American Society of Agricultural Engineers, Tampa, Fla.
Sailor, D. J. (2008). “A green roof model for building energy simulation programs.” Energy Build., 40(8), 1466–1478.
Snodgrass, E. C., and Snodgrass, L. L. (2006). Green roof plants: A resource and planting guide, L. L. Snodgrass, translator, Timber, Portland, Ore.
VanWoert, N. D., Rowe, D. B., Andresen, J. A., Rugh, C. L., Fernandez, R. T., and Xiao, L. (2005a). “Green roof storm-water retention: Effects of roof surface, slope, and media depth.” J. Environ. Qual., 34(3), 1036–1044.
VanWoert, N. D., Rowe, D. B., Andresen, J. A., Rugh, C. L., and Xiao, L. (2005b). “Watering regime and green roof substrate design affect Sedum plant growth.” HortScience, 40(3), 659–664.
Information & Authors
Information
Published In
Journal of Hydrologic Engineering
Volume 15 • Issue 6 • June 2010
Pages: 395 - 403
Copyright
© 2010 ASCE.
History
Received: Dec 1, 2008
Accepted: Apr 2, 2009
Published online: May 14, 2010
Published in print: Jun 2010
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