Characteristics of a Recent and Prehistoric Landslides in the Pine River Valley, BC: a Mapping Effort

Abstract:

Spreads and other low gradient landslides are common in glacial lake sediments in north eastern British Columbia. Both pre and post glacial lake sediments, largely derived from shale bedrock are susceptible to low-gradient landslides. Bank erosion by rivers and streams and high pore pressures, have contributed to the landslides. We used LiDAR for mapping the extent of the glaciolacustrine sediments and map and characterise landslides in the Pine River valley, near Chetwynd, British Columbia. We included metrics such as travel angle, length, area, and elevation to distinguish rotational and translational landslides. We mapped 45 landslides in the Pine River valley distinguishing between rotational and translational landslides. The rotational landslides commonly have a smaller area and smaller travel length than translational landslides. Most rotational slides involved overlying alluvial fans, while most translational slides involved terraces.