Innovation Winter 2025/26

Rockslide monitoring tools: benefits and limitations

Technology

Benefits

Limitations

• High-resolution 3D mapping of terrain • Effective in vegetated areas via bare-earth DTMs • Reveals subtle morphological features of landslides • Detects millimeter-scale ground deformation • Useful for identifying slow-moving landslides • Operates in all weather and lighting conditions • Increasing temporal resolution with newer satellites • Non-invasive subsurface imaging • Detects voids, fractures, and buried features. • Real-time data acquisition in the field • Wide area coverage and frequent updates • Enables change detection and inventory mapping • Useful for inaccessible or hazardous terrain

limitation that we kind of are forced to live with: it is very difficult to image the subsurface. GPR can only be used in a limited number of earth materials. It typically does not tell you much on rock slopes, but it can give you penetrations, structure, and some soil materials down to about 20 or 30 metres.” Generally, GPR struggles in clay-rich, wet, or saline environments where radar signals are absorbed, reducing penetration depth and clarity. Another limitation is that high-frequency antennas offer better resolution but shallow penetration, while low-frequency antennas reach deeper but with less detail. This trade-off can hinder detection of deep-seated fractures or voids. • Limited depth in conductive or saturated soils • Requires close surface contact as terrain and vegetation can hinder use. • Interpretation is complex and resolution decreases with depth. • Optical sensors depend on weather and daylight • Lower resolution than LiDAR or InSAR • May miss subsurface features without integration with other tools • Limited penetration through dense vegetation, snow, or water • Accuracy depends on point cloud density and processing algorithms • Older datasets may miss recent changes • Susceptible to atmospheric noise and decorrelation • Limited by satellite revisit intervals and data availability • Requires complex processing and interpretation

LiDAR (Light Detection and Ranging)

InSAR (Interferometric Synthetic Aperture Radar)

GPR (Ground- Penetrating Radar)

Remote Sensing (optical, photogrammetry, UAV, satellite)

and generate high-resolution 3D models of terrain, vegetation, and built environments, crucial for mapping landslide-prone areas with precision. LiDAR can scan an area more frequently than InSAR satellites can, and LiDAR sensors can be attached to drones, increasing their usefulness. However, because LiDAR leverages light to measure an environment, it is limited to surface observation. “Right now, InSAR and LIDAR data are more accurate than installing extensometers, but they just scan the surface; they don’t provide any subsurface information to us,” Amini said. GPR can be a solution to that problem, but only if subsurface conditions allow for it, Clague said. “That’s a

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Winter 2025/26

Innovation