• Rocky Mountain Research Station
• 240 West Prospect
• Fort Collins, CO 80526
• (970) 498-1100

Objective Mapping of Bedrock Landslides Using Lidar

Most large slides move very slowly and often support a forest on their surface. This makes them quite difficult to detect and investigate using traditional remote sensing or field-based techniques, despite their large size. It is also extremely expensive and time-consuming to use traditional geotechnical engineering methods to evaluate the level of activity of a landslide and estimate its sensitivity to changes in land use, such as road building or timber harvesting.

Researchers at the Boise Aquatics Sciences Laboratory have used new analyses of very high resolution digital terrain models to detect and objectively map large landslides, even when they are obscured by a full coniferous forest canopy. The terrain models are produced from high density airborne lidar (light detection and ranging) data and the models are analyzed by both statistical and spectral analysis methods. We have demonstrated that patterns of topographic roughness seen in the terrain models allow us to map the slides and begin to evaluate their mechanics and recent level of activity. Work is now on-going to link our observations of surface roughness with physical and numerical models of slide mechanics and investigate the effects of slide material mechanical properties.

Using these techniques, forest managers will be able to quickly map large landslides over extensive areas, objectively evaluate their activity and likely response to land use and climate change, and adjust management plans accordingly. Managers will also have another tool to help them understand the spatial and temporal patterns of the physical controls on aquatic habitat.

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