In response to projected global warming, nearly half of the Fraser River basin, Canada’s largest Pacific watershed, is expected to transition from one that is snow-dominated to a primarily rain dominated regime by the end of this century, according to a new hydrology study based at the University of Northern British Columbia.
The research reveals that the Fraser River basin transitions from one where peak annual streamflow results from spring snowmelt to one where the peak stream flow is often caused by extreme rainfall.
Dr. Stephen Déry, a UNBC Environmental Science Professor and Dr. Siraj Ul Islam, a UNBC Environmental Science Research Associate, ran a hydrological model for 150 years, from 1950 to 2099 using future climate projections from 21 global climate models.
The projections show in a future, warmer climate that as the ratio of snow to rain declines, river flows peak earlier in the year with reduced volume. Runoff in the cold season (fall and winter) at the outlets of the Fraser River and its major tributaries increase substantially and its year-to-year variability more than doubles compared to the historical time period.
Continue reading at University of Northern British Columbia.
Image via University of Northern British Columbia.