PCIC Scientists in Atmosphere-Ocean Special Issue on the Columbia River

The journal Atmosphere-Ocean has just released a special issue focused on the Columbia River, which includes an article by PCIC hydrologists: Arelia Werner, Markus Schnorbus and Rajesh Shrestha. Their work involved using a hydrologic model that included a simple representation of glaciers, run by statistically-downscaled output from global climate models, in order to come up with projected changes to evaporation, precipitation, runoff, snow, soil moisture and  temperature in the Canadian portion of the Columbia River Basin. Using more sophisticated emissions scenarios and newer models, they find a greater decrease in summer precipitation and a greater increase in annual precipitation than was found by earlier studies. Also, their projections suggest that the Canadian portion of the Columbia Basin will respond to climate change differently than the rest of the Columbia Basin, with larger decreases in summer streamflow and larger increases in annual streamflow. Lead author Arelia Werner says that, "[a]nnual streamflow is expected to increase by 11 to 27 percent in 2071-2098 in the Columbia and Kootenay rivers north of the Canada/US border versus average conditions for 1961-1990. This annual increase will come from increasing flows in winter and spring. Decreased flows are projected in the summer months in both basins, with up to a 55 percent decrease in August in the more southern Kootenay river basin due to higher evaporation rates."

Other articles in the issue examine future projections of river flows and climate extremes in the Columbia Basin, the effect of water and environmental management behaviours on water resources and vulnerabilities, the effect of climate oscillations on year-to-year variation in river flows and the glacier monitoring programme in the upper Columbia.

Draining an area of 670,000 square kilometres, the Columbia River runs for 2000 kilometres, from the Rocky Mountains in BC, through Washington and along Washington's border with Oregon where it empties into the Pacific Ocean. It is heavily dammed, being the largest hydroelectric-producing river in North America, and supports forestry, agriculture, fisheries, and recreation, as well as providing water to 145,000 people.

For more information on this issue, see this press release or view the special issue of Atmosphere-Ocean, here.