Slope-failure mechanisms, catastrophic mass flow processes and public perception of risk in British Columbia and Southern Patagonia.

NERC : Holly Chubb : NE/S007512/1

Mountainous environments present a variety of risks to human population in the surrounding communities. Damages resulting from triggered natural hazards can cost governments and individuals millions of pounds annually to restore public buildings, roads, and houses. Landslides in mountainous regions are a particularly deadly form of natural hazard due to their unpredictability and potential scale, resulting in thousands of deaths every year. Regions such as Canada and Chile have extensive mountainous ranges in the form of the Canadian Rockies and the Patagonian Andes respectively, placing higher populations at-risk; but this risk is often not well understood. There is still debate in the scientific community about the different factors that cause an area to be at risk of a landslide, as well as a lack of research into how to accurately communicate the posed risk to affected communities.

Climate change is one of the greatest challenges that humans as a species have faced in modern history, inflating the risk of natural disasters in both frequency and magnitude with landslides being no exception. As the planet warms, ice and snow from ice sheets and glaciers is decreasing. This is an important factor as ice helps to stabilise mountain slopes by acting as a cement between rock particles. Ice loss results in large areas of unstable and weakened mountain slopes that no longer have a sufficient amount of ice to keep them intact. A small trigger, such as a day of intense rainfall or a minor earthquake, can result in the collapse of huge areas of rock creating a landslide as it progresses down slope. Research into predicting these failures and understanding how we can determine the size of a failure is essential to protect communities that live within mountainous regions. This research aims to use satellite imagery, alongside primary surveying data and sediment sampling, to help further understand this hazard. By looking at previous landslide events on satellite imagery it will be possible to identify pre-conditioning factors such as cracks, faults, or minor rock falls, that precede a movement. This information can be applied to slopes that we already understand to be unstable to monitor their deformation and predict future catastrophic failure. Sediment samples from previous landslide events will also inform us of the behaviour and dynamics of previous landslide events which could help to predict the area that a future event may affect, assisting in hazard mitigation strategies.

Both the Mount Meager Massif and Southern Patagonian Ice field have experienced ice loss at an unprecedented rate in the 21st century as a consequence of climate change, which makes it highly likely that their communities will continue to suffer from increased and more frequent landslide events. Populations are also increasing in these areas, further extending the impact of landslide risk. It is therefore important that any research undertaken in this field is communicated to local people in an understandable and informative manner. This requires investigation into the existing perception of risk from landslides and how individuals would like both scientific organisations and research teams, as well as governments, to communicate this risk to them. It is only through geographical and social research, combined with effective communication strategies, that this risk can be effectively mitigated.