CGRG Bibliography of Canadian Geomorphology
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Author : Dhakal, A.S.; and Alila, Y.
Date : 2003.
Title : Assessment of impacts of forestry practices on shallow landslides in Carnation Creek Watershed, British Columbia.
Publication : Canadian Geophysical Union. Annual Meeting, May 10 -14, 2003. Banff Centre, Banff, Alberta.
Issue :
Page(s) :
Abstract
The impact of forest management practices related to timber harvesting on slope movement was assessed in the Carnation Creek watershed (10 Km 2 ), Vancouver Island, British Columbia. Carnation Creek lies within the Coastal Western Hemlock Biogeoclimatic Zone where the forest harvesting initiated in 1977. Landslide locations were determined from existing information and the stereopairs of vertical aerial photographs taken at different periods. Using the multitemporal aerial photographs, approximate date of landslides occurrence was also established. Geomorphically significant rainstorms were extracted from the eighteen years of hourly precipitation records (1972 – 1990) to empirically relate the rainstorm characteristics associated with landslide occurrence. The spatial and temporal distributions of landslides were analyzed in GIS with respect to forest roads, major culverts, harvesting period, and harvesting method. The geo-environmental factors influencing landsliding were determined from the topographic factors derived from a digital elevation model, soil, vegetation, and, geology. This investigation intends to evaluate the spatial and temporal nature of forest management practices on landslide occurrences. Current qualitative method of terrain stability classification and mapping in British Columbia depicts existing landslide hazard based on subjective decision rules. Because landslides will be more likely to occur under conditions similar to those of past landslides, the study of site characteristics of landsides associated with forest practices provide opportunity of development of quantitative method of landslide hazard in order to assess the potential areas of future landsliding in the similar bio-geoclimatic regions.
Bibliography of Canadian Geomorphology