Examining the Feasibility of Sentinel-1 InSAR data for landslide monitoring and failure forecasting in western Canada.
Date
2024-01-03
Authors
Blenman, Peter
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Abstract
Landslides are geological hazards that significantly threaten human life, infrastructure, and biotic
habitat in areas with steep slopes. Precursory signs of a landslide can be undetectable or non-
existent, making the evacuation of residents unlikely. The ongoing climatic cycles and geological
triggers imposed on regions susceptible to landslides exhibit long-term ground movement
superimposed with accelerations due to seismicity or precipitation. Landslide monitoring and
forecasting aims to understand the structural dynamics of the slide accelerations to estimate
when there will be a catastrophic failure. The thesis explores the potential of InSAR technology
for monitoring slope movement in the western Canadian Cordillera. The study takes a two-
pronged approach: first, investigating the capability of the technique to detect movement on
slopes that have already undergone previous landslide activity, focussing on the Garibaldi
Volcanic Complex (GVC) as a case study, and second, analyzing five sites that have recently
experienced landslides to determine if InSAR technology could have forecasted the failures.
The InSAR results presented in the thesis show that ground displacement occurred on the slopes
of all the study sites, which corresponded with previous landslide activity. However, InSAR
results collected during winter months were less detailed and frequent than those collected using
a seasonal approach. The forecasting study discovered that all the sites displayed signs of
preceding movement on the slopes, which were successfully detected by InSAR. Furthermore,
each site encountered extreme weather conditions, resulting in catastrophic failure. The Elliot
Lake and Ecstall River sites experienced seismic activity the same afternoon as the landslide
events, potentially connected to glacial loss and retreat. Results obtained during snowfall were
less reliable than the summer acquisitions.
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The results from the thesis demonstrate that the Sentinel-1 mission's temporal resolution is
inadequate for creating a real-time monitoring system for landslide-prone slopes in western
Canada. Factors that trigger landslide acceleration, such as precipitation, seismicity, and
geological processes, can occur over decades or hours. Hence, the primary role of Sentinel-1 in
landslide monitoring is identifying large-scale moving slopes. Future InSAR platforms could
provide a promising solution with high temporal resolution, making landslide forecasting and
monitoring a reality.
Description
Keywords
Risk assessment, Landslides, Climate change, InSAR, Remote sensing