Landslide risk evolution and the adequacy of risk evaluation criteria

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Landslides in Canada are responsible for an average of four fatalities each year and cause ~$200 million of damage annually. Landslide management depends on government resources, and risk levels are evaluated through Factor of Safety, Probability of Failure, risk rankings or quantitative risk assessments. These risk levels can vary with time, and if their variability is not adequately understood and quantified, the likelihood of slope failures and their negative consequences can increase. Risk variability is attributed to the level of knowledge about the landslide, progressive degradation of materials, and external factors (particularly weather); however, limited studies address the fundamental processes behind risk variability with time. My previous work focused on the development of frameworks for quantifying landslide risk considering uncertainty for a variety of parameters. These frameworks were developed under the current state of knowledge regarding risk variability and were practical in nature. The proposed work will now advance the fundamental study of landslide risk variation with time, particularly in light of climate change, and assess the adequacy of landslide risk acceptability criteria. To the best of my knowledge, this research will generate new knowledge in the physics of landslide evolution, which will inform the development of practical approaches toward landslide risk management. The first objective is to understand the fundamental processes in landslide risk variation for two sites with different types of landslides: a compound landslide and a slope prone to rock falls. This work will develop a framework for estimating risk variations with changes in landslide deformation patterns and external factors, particularly in the context of climate change, and develop numerical realizations of the compound landslide to adapt the landslide risk analysis process to estimate seasonal and long-term risk variability. The second objective is to quantify the impact of model uncertainty when analyzing a cut-slope within a reservoir and to assess the adequacy of evaluation criteria at different stages of the life of a cut-slope (design, construction, operation, long-term). This work will monitor the slope through remote sensing coupled with in-situ instrumentation to faciliatate the development of an approach to evaluate uncertainty reduction and develop a numerical approach to estimate changes in slope behaviour in the long term to assess the most adequate slope risk criteria at different stages of the life of a cut-slope. The research program will train two PhD students and a Research Associate and will advance the fundamental understanding of seasonal and long-term changes in landslide risk, particularly associated with climate change. This will provide the basis for addressing current and future changes in landslide risk to assure continuous and sustainable economic development in terms of public and environmental safety.