A new study by UNBC researchers details the impacts of a rapidly declining mountain snowpack on streamflow timing of the Fraser River Basin.

The study, a collaboration between UNBC Environmental Science Professor Dr. Stephen Déry and UNBC post-doctoral fellow Siraj ul Islam, was published on Jan. 27, 2016 by the Nature Publishing Group in their journal Scientific Reports. The paper is available (open access) at: http://www.nature.com/articles/srep19299

They found that although the total amount of annual precipitation in the Fraser River Basin has remained nearly stable between 1949 and 2006, changes in the type of precipitation and the timing of it, coupled with warmer air temperatures, have led to a significant decline in peak seasonal snowpack accumulation.

“Over our study period of 1949 to 2006, the contribution of snow to Fraser River flows declined 19 per cent,” said UNBC Environmental Science Professor Dr. Déry. “This large decrease has led to an average 10-day advance of recent spring snowmelt pulses in the river. It also has resulted in a more rapid transition to lower flows during the summer. This can lead to warmer water temperatures that are possibly unfavorable to migrating salmon.”

Flows on the lower Fraser River can also be predicted by simply tracking observed data upstream at the Fraser River at Shelley and the Thompson River near Spences Bridge.

The paper, entitled Impacts of a Rapidly Declining Mountain Snowpack on Streamflow Timing in Canada’s Fraser River Basin, studied the trends in the daily streamflow of the Fraser River’s main stem and six of its major tributaries over 1949-2006 when air temperatures rose by 1.4 degrees Celsius while annual precipitation amounts remained stable.

Identification of the sub-basins driving the Fraser River’s most significant changes provides a measure of seasonal predictability of future floods or droughts in a changing climate.

The research team also included Do Hyuk “DK” Kang, a former post-doctoral fellow at UNBC who is now a post-doctoral fellow at the NASA Goddard Space Flight Centre; Huilin Gao, Assistant Professor, Texas A&M University; and Xiaogang Shi, Research Scientist at the Commonwealth Scientific and Industiral Research Organisation (CSIRO) Land and Water.

This research is directly funded by the Natural Sciences and Engineering Research Council (NSERC). The Research Support Fund, a tri-agency initiative of the Social Sciences and Humanities Research Council (SSHRC), NSERC, and the Canadian Institutes of Health Research (CIHR), assists Canadian post-secondary institutions and their affiliated research hospitals and institutes with the expenses associated with managing the research funded by these three federal research granting agencies. The University of Northern British Columbia recognizes the value of this support and appreciates this ongoing research investment.