NEW UPDATES OF PCIC

PROJECT AND RESEARCH UPDATES IN PCIC

Project Spotlight: Rivers Climate Change Indicators

In August of 2017, interactive maps that show changes to the timing and volume of river flow, using data from analysis performed at PCIC, were published. These accompany updates to a British Columbia (BC) Ministry of Environment and Climate Change Strategy (MoECCS) report on climate indicators in BC, to which PCIC has also contributed. Rivers and the ecosystems that they support provide a variety of services to communities in the province. Changes to river flow can result in impacts, such as floods, that affect these services.

Seventeen stations—places where river flow data is recorded using gauges—were suitable for trend analysis, six with records extending back for about 100 years and 11 with records for about the last 50 years. Most stations showed significant increases in minimum daily flow and insignificant decreases in maximum daily flow over 1912-2012, while the magnitude and direction of change in mean aual and seasonal flow varied by river basin. Changes in river flow depends on a basin’s location, size, elevation, and flow regime. Changes in flow volume for the 55-year period, 1958-2012, were similar to those for the 1912-2012 period except that, in the latter period, decreases in mean and minimum summer flows occurred at all stations. Finally, the date by which half of the aual water volume has passed the gauging point came earlier by about a week at the majority of locations over both periods.

The updated report contains some discussion of factors that influence river flow and projected future changes to key rivers in BC. In particular, projections suggest that the aual flow volume of the Fraser, Peace and Upper Columbia Rivers may increase by the 2050s. Projections suggest seasonal changes that vary in their details between rivers, but all four of the rivers that the researchers examined, the Campbell, Fraser, Peace and Upper Columbia, show increased winter flows and decreased summer flows.

The results of this analysis are now available in an interactive online map at Environmental Reporting BC, and as a section in an updated report on climate change indicators in BC from the MoECCS. This update, and other climate indicator updates to which PCIC contributed in 2015 and 2016, can be found in the report below.

Paper on Hotter Summers Published

Increased summer temperatures can have impacts on human health, water quality and increase energy needs for cooling. Recent research on extremely warm summers, led by PCIC research associate Chao Li and co-authored by PCIC Director Francis Zwiers suggests that by the middle of the century, current record-breaking temperatures will be the norm. The work has been published in Earth’s Future and featured on both CBC News and UVic News, as well as local Victoria media.

Their research examines historical and projected changes to summer mean wet bulb globe temperatures (WBGT), an indicator that takes into account both air temperature and humidity, and is often used as a measure of potential heat stress on people. The authors’ results suggest that, at least half of all summers may exceed the current maximum summer average WBGT on record by the 2030s and by mid-century 95% of all summers may surpass it. In addition, they examine a number of regions comprising most of the Northern Hemisphere over the 1973-2012 period and find that the changes in summer mean WBGT caot be explained by natural influences alone.

Visit the website.

Read the original paper.