Water Stewardship Information Sources

Citation Thompson, B. 1998. Terrain attribute study: slope failure frequencies following logging in coastal British Columbia. In: Hogan, D.L., P.J. Tschaplinski, and S. Chatwin (Editors). B.C. Min. For., Res. Br., Victoria, B.C. Land Manage. Handb. No. 41.
Organization FLNRO
URL https://www.for.gov.bc.ca/hfd/pubs/docs/Lmh/Lmh41.htm
Abstract/Description or Keywords The identification of terrain that will be subject to
slope failures following logging or road building is a
high priority for forest management in coastal
British Columbia. This information can be used at
the planning level to ensure that annual allowable
cuts (AAC) calculations reflect the land base truly
available for harvest, and at the development stage
to ensure that environmentally sensitive areas are
not damaged.
There is a need for a more objective and quantitative
approach for the prediction of post-logging
slope stability. This approach requires the collection
of data on the frequency of slope failures following
logging, so that the reliability of the criteria used by
mappers for slope stability assessments can be
improved.
An empirical approach, applied to a representative
sample of landscape units over a wide geographical
area, has potential for quantifying the
likelihood of landslide occurrence. The objectives of
the study are two-fold:
1. to characterize steepland terrain types that are
subject to slope failures following conventional
clearcutting and road building, and those which
are not; and
2. to develop a multi-factor terrain-based stability
classification system that addresses the likelihood
and frequency of slope failures occurring following
conventional clearcutting and road building.
The study area involves a number of large contiguous
land units within the western portion of the
Insular Mountains of Vancouver Island, and the
Cascade Mountains and southern Coast Mountains
on the British Columbia mainland. The study is
ongoing; data acquisition is completed for the
Vancouver Island portion, and data acquisition for
the Cascade and Coast mountains will begin this
field season.
Methodology, including data collection and
analysis, were presented. An example of results of
analysis of a limited set of data was also presented.
Information Type abstract
Regional Watershed Coast Region
Sub-watershed if known
Aquifer #
Comments
Project status complete
Contact Name
Contact Email