Citation | Fannin, J, Bonin, D and Dunkley, D. 2008. Quantitative back-analysis of partial risk: Jamieson Creek debris flow. In: In : J. Locat, D. Perret, D. Turmel, D. Demers et S. Leroueil, (2008). Proceedings of the 4th Canadian Conference on Geohazards : From Causes to Management. Presse de l’Université Laval, Québec, 594 p. |
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Organization | UBC |
URL | http://www.geohazards.ggl.ulaval.ca/evaluation/fannin.pdf |
Abstract/Description or Keywords | Storm precipitation during November 1990 caused a debris slide within a forest clearcut in the Jamieson Creek watershed. The debris slide progressed to a debris flow as it moved over the logged terrain, then entered and resulted in sedimentation of Jamieson Creek. Post-event analysis of the factor of safety of a potential failure plane at the point of origin in the cutblock suggests the probability of a specific hazardous landslide occurring, in this case the debris slide, to be 0.26. The slope stability analysis is based on measured soil properties, interpretation of groundwater monitoring data, and some assumed geotechnical parameters. Attributes of the slope below the point of origin indicate the probability of the resulting debris flow entering Jamieson Creek to be certain or 1, given the occurrence of the debris slide. The travel distance analysis is based on a consideration of slope angle, and a flow behaviour that was unconfined for most of the travel path. Accordingly, the post-harvesting back-analysis shows that the partial risk to Jamieson Creek from a debris slide initiating near the top of the cutblock and the resulting debris flow entering the creek to be 0.26. |
Information Type | conference article |
Regional Watershed | Lower Fraser |
Sub-watershed if known | |
Aquifer # | |
Comments | |
Project status | complete |
Contact Name | Jonathan Fannin |
Contact Email | [email protected] |