281
Views
1
CrossRef citations to date
0
Altmetric
Research Articles

Annual discharge trends for Canadian rivers

ORCID Icon, &
Pages 423-434 | Received 16 Nov 2017, Accepted 15 Jul 2018, Published online: 29 Aug 2018
 

ABSTRACT

This investigation into trends in annual discharge of Canadian rivers focuses on long-term hydrometric stations having record lengths of at least 75 years. Eliminating stations with significant non-stationarities in mean annual discharge, and stations having evidence of a large diversion or a withdrawal, resulted in a final streamflow dataset of 113 Water Survey of Canada, WSC, hydrometric stations. In order to assist with the identification of potential factors contributing to a trend, at least one representative long-term climate station was selected for each long-term hydrometric station. A comprehensive trend assessment was completed on both annual discharge and precipitation (rainfall, snowfall, and total). Of the 113 long-term hydrometric stations, significant trend was identified at 21 sites: four associated with anthropogenic activities in the watershed, eight consistent with climate change (i.e. changes in annual rainfall, or annual snowfall or annual precipitation) and the remaining nine consistent with some combination of climate and anthropogenic activities. With respect to the climate stations, about 50% had a significant trend in total precipitation without a corresponding significant trend in annual discharge. The ratio of discharge stations with significant trend to climate stations with significant trend varied with ecoregion, from 0% to 40%. Factors contributing to this discrepancy include a possible compensating trend in evapotranspiration and a watershed that is relatively insensitive to small changes in precipitation.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by Canadian Defence Academy Research Program [grant number W4938-18-061].

Reprints and Corporate Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

To request a reprint or corporate permissions for this article, please click on the relevant link below:

Academic Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

Obtain permissions instantly via Rightslink by clicking on the button below:

If you are unable to obtain permissions via Rightslink, please complete and submit this Permissions form. For more information, please visit our Permissions help page.