Climate and hydrological circumstances antecedent to selected landslide events in southeastern British Columbia
Title | Climate and hydrological circumstances antecedent to selected landslide events in southeastern British Columbia |
Publication Type | Conference Proceedings |
Year of Conference | 1991 |
Authors | Toews, D. A. |
Conference Name | 59th Annual Western Snow Conference |
Series Title | Proceedings of the 59th Annual Western Snow Conference |
Date Published | April 1991 |
Publisher | Western Snow Conference |
Conference Location | Juneau, Alaska |
Keywords | British Columbia, Mass washing |
Abstract | Debris torrents and debris avalanches in southeastern B.C. are usually associated with snowmelt. The hydroclimatic circumstances and possible influence of forest harvesting on 6 landslide cycles that occurred over a 10 year period are investigated in this paper. Slides appear to occur when a rain storm or a hot spell coincide with peak snowmelt at the particular elevation zone above an unstable slope. Melt may be due to either rain-on-snow or radiation and case studies of slides illustrating each circumstance are examined. The event that caused the largest amount of impact was a 90 mm rain-on-snow event on July 12, 13, and 14, 1983. This storm caused hundreds of debris torrents in watersheds with a significant area above 2000 m, the approximate snow line at the time of the slides. In 1988 at least 10 debris avalanches were associated with a radiation event in mid April, when the snow line was at a much lower elevation. Snowmelt data collected from a nearby lysimeter indicated peak snowmelt of 22 and 40 mm respectively in a forested and clearcut site. |
URL | sites/westernsnowconference.org/PDFs/1991Toews.pdf |