Rainfall Interception by Mature Coastal and Interior Forests in British Columbia
Interception of rainfall by forest canopies and its evaporation back to the atmosphere is an important component of the hydrological balance. We quantify the influence of six mature forests at two coastal and one southern interior locations in British Columbia on interception loss. Drainage from the canopy was measured with throughfall troughs and stemflow collars that emptied into tipping buckets monitored by data loggers. Interception loss was evaluated on an event basis and summed to monthly and seasonal totals. The throughfall coefficients increased with a decrease in canopy volume with values of 0.3 for the south coast forest, 0.5 for the north coast forests, and 0.6 for the southern interior forests. The respective saturation capacities were 2.0, 1.1, and 0.6 mm. The average evaporation rates during events varied from 0.05 to 0.3 mm h-1 at all sites. Consequently, for large events, interception loss was dominated by evaporation and replenishment of water in storage during the event. Increasingn event size increased interception loss, which tended to plateau at large events. The coastal forests had throughfall 75±2 percent, stemflow 1±0.2 percent, and interception loss 24±2 percent of the May to November rainfall. The respective values for the interior forests were 72±3 percent, 0.05±0.05 percent, and 28±3 percent of the late May to October rainfall. The similarity between coastal and interior sites in the partitioning of the seasonal rainfall resulted from the differing distributions of event size and similar evaporation rates of intercepted water during events.
How to Cite
LicenseCopyright (c) 2023 Dave Spittlehouse, Dave Maloney
Submission of an original manuscript to the Journal will be taken to mean that it represents original work not previously published, that it is not being considered elsewhere for publication; that the author is willing to assign copyright to the journal as per a contract that will be sent to the author just prior to publication and, if accepted for publication, it will be published in print and online and it will not be published elsewhere in the same form, for commercial purposes, in any language, without the consent of the publisher. The author licenses the right of exclusive publication to Confluence for one year and agrees to cite the journal as the original publisher in all subsequent uses under the author's control or influence.
The journal takes the stance that the publication of scholarly research is meant to disseminate knowledge and, in a not-for-profit regime, benefits neither publisher nor author financially. It sees itself as having an obligation to its authors and to society to make content available online now that the technology allows for such a possibility.
Authors who publish in Confluence: Journal of Watershed Science and Management agree to release their articles under the Creative Commons Attribution-Noncommercial-No Derivative Works 2.5 Canada Licence. This licence allows anyone to copy and distribute the article for non-commercial purposes provided that appropriate attribution is given. For details of the rights an author grants users of their work, please see the licence summary and the full licence.