CGRG Bibliography of Canadian Geomorphology
Search Results
Author : Aylsworth, J.M.; and Egginton, P.A.
Date : 1994
Title : Sensitivity of slopes to climate change.
Publication : Mackenzie Basin Impact Study (MBIS), Interim Report 2 Proceedings of the Sixth Biennial AES/DIAND Meeting on Northern Climate & Mid Study Workshop of the Mackenize Basin Impact Study, Yellowknife, Northwest Territories, April 10-14, 1994. Edited by: J. Cohen. - Downsview, Ont. : Environment Canada,
Issue :
Page(s) : 278-283
Abstract
The Mackenzie Valley and Delta region is one of three areas in Canada selected by the Geological Survey of Canada as a focus for Global Change Research. As one of our activities within this area, we have compiled a landslide inventory for the Mackenzie Valley and adjacent mountains, from the Beaufort Sea south to the Territorial border. Within this area we have mapped some 3400 landslides. An area of this size includes a tremendous variety of physical conditions. The types of landslides and their mechanisms of failure vary accordingly. ... Although many landslides in this region are not related to climate, for example, those failures induced by earthquakes or river erosion, there are many landslides which are related to climatic or thermal factors. Ground ice is associated with many, perhaps most, landslides. Thermal instability in permafrost slopes can result from changes in proximity of warm waters or from the destruction of the insulating organic cover by fire. Other landslides are directly related to extreme climate events such as abnormally high precipitation events or high summer temperatures. Thus permafrost slopes can result from changes in proximity of warm waters or from the destruction of the insulating organic cover by fire. Other landslides are directly related to extreme climate events such as abnormally high precipitation events or high summer temperatures. Thus permafrost regions are sensitive to climate change and areas of icy sediment or massive ice will be highly susceptible. In the south, in the Fort Simpson area, with a simple 3 C warming of mean annual temperature over a 50 year period, some areas of permafrost will totally degrade. Further north only the active layer will thicken. In areas of permafrost both annual climatic variability and longer duration changes in climate must be a major consideration. Both are expected to change with global warming. ... In the Mackenzie Valley and adjacent regions the major impact of increased landslide activity in the case of global warming would concern infrastructure - primarily location, design, and construction of pipelines, roads, and bridges. River navigation might be affected in the event of a landslide dam on a river. As well, landslide dams could cause further thermal instability upstream, possibly promoting additional landslides. Increased landslide activity could also impact on fisheries through possible increased siltation in streams and rivers and possible destruction of spawning beds. (Author)
Bibliography of Canadian Geomorphology