Comparison of Evapotranspiration Computation by FAO-56 and Hargreaves Methods
Publication: Journal of Irrigation and Drainage Engineering
Volume 142, Issue 8
Abstract
In an urban environment, vegetated roofs are sustainable systems that provide a variety of valuable benefits, such as the reduction of stormwater volumes and the mitigation of urban heat islands strongly linked to their evaporative processes. The evapotranspiration (ET) is one of the most important processes of the hydrological cycle, but it also represents one of the most difficult hydrological phenomena to quantify because of the complex interaction between the ground surface, vegetation, and atmosphere. However, an accurate computation of ET from vegetated roofs is essential to properly predict the benefits of such systems. The aim of this paper is to evaluate and compare three ET models for the prediction of ET from a green roof: a combination model and two temperature-based models under Mediterranean climate conditions. The study was carried out on an experimental green roof, located at University of Calabria, Italy, by using the onsite data with a time step of 5 min and a monitoring period ranging from September 2013 to June 2014. The study demonstrated that the two temperature-based models produced results that were in good agreement with those obtained from the combination model when onsite data from an extensive green roof located in a Mediterranean area were used.
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Acknowledgments
The study was cofunded by the Italian National Operative Project (PON), Research and Competitiveness for the convergence regions 2007/2013-I Axis “Support to structural changes” operative objective 4.1.1.1, “Scientific-technological generators of transformation processes of the productive system and creation of new sectors,” and Action II: “Interventions to support industrial research.”
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Published In
Journal of Irrigation and Drainage Engineering
Volume 142 • Issue 8 • August 2016
Copyright
© 2016 American Society of Civil Engineers.
History
Received: Jun 19, 2015
Accepted: Jan 20, 2016
Published online: Apr 7, 2016
Published in print: Aug 1, 2016
Discussion open until: Sep 7, 2016
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