Rainfall Interception in an Urban Environment: Results of UBC Tree Canopy Research published




Urban Trees Intercept More Rainfall Than Trees in Forested Environments

During the period 2005 through 2010, the City of North Vancouver, District of West Vancouver, District of North Vancouver, Water Balance Model  Partnership, University of British Columbia (UBC), Metro Vancouver, Ministry of Community & Rural Development, Real Estate Foundation of British Columbia, and Canada Water Network collaborated to fund and implement the North Shore Tree Canopy Interception Research Project.  A network of 60 tree canopy climate stations was installed across the North Shore region.

The purpose of the Project was to quantify the proportion of rainfall intercepted by the tree canopy in an urban forest. The Project can inform urban planning by providing a science-based understanding regarding the benefits of maintaining a tree canopy in the urban environment.

“We applied a unique methodology for measuring rain/throughfall under  different urban trees using a system of PVC pipes hung beneath the canopy to capture the throughfall where it drained into a rain gauge attached to a data logger,” states Yeganeh Asadian, the UBC researcher who undertook the study under the direction of Dr. Markus Weiler and Dr. Hans Schreier.

“To ensure that the study adequately captured the range of throughfall variability, trees were selected to sample different landscape sites (streets, parks, and natural forested areas), elevations, tree type, health condition and species, including Douglas-fir, Western red cedar, Bigleaf maple, Oak, Copper beech, Horse chestnut,  Cherry, and Poplar.”

“The results showed that urban trees intercept and evapotranspire more rain than trees in forested environments. Together with the delay in runoff trees can act as an effective rainwater management tool on individual properties,” concludes Yeganeh Asadian.


To download a copy of the Master of Science thesis completed by Yeganeh Asadian at the University of Britsh Columbia, click on Rainfall Interception in an Urban Environment


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