For the most part, a warmer Earth will be a wetter Earth and this has the potential to cause substantial changes to Canada's rivers. Increased frequency and magnitude of flood flows will increase the hazard to structures, buildings and humans. The effects of predicted climate change will be superimposed on, and may amplify, the existing impact of human activity on rivers.

Map 4 larger image [GIF, 69.7 kb, 716 X 541, notice]

Map 4 summarizes the regional sensitivity of rivers to predicted climate change in Canada. The most sensitive regions include the Atlantic coast and the Great Lakes-St. Lawrence Valley regions. This is a result of the shift to more intense rainstorms (rather than snowmelt) as the main flood generator. Small streams in urban areas may be particularly problematic. Flows are also likely to increase in the Southern Cordillera and eastern slopes of the Rocky Mountains. This will affect large Prairie streams while smaller Prairie-fed streams risk flooding from increases in thunderstorm activity. While the most direct effect of predicted climate change will be to increase flood and river erosion hazards, the impact will extend to the use and value of rivers for recreation, habitat, fisheries, water supply, and transportation.

Contact:

Peter Ashmore
Department of Geography
University of Western Ontario
London, ON
N6A 5C2
519-661-2111 ext.85026
Email: pashmore@julian.uwo.ca