Monitoring snow conditions to predict avalanches is very difficult as the starting locations are often hard and dangerous to access. In collaboration with Quest University we developed an avalanche surveying program to support the Ministry of Transportation Infrastructure in British Columbia to more effectively manage avalanche hazards. An important benefit of using RPAS is that they provide high-resolution images making spatially accurate surveillance of avalanche terrain possible throughout the winter season. Furthermore, by using RPAS there is less need for avalanche professionals to go out under adverse mountain conditions and reduce the deployment of costly helicopters.
A key aim is to remotely measure snow depth by comparing digital elevation models (DEMs) of the summer (barren ground) and winter. This is a challenging task due to the harsh environmental conditions in winter and the long range required to reach the more remote sites. After trying a variety of different RPASs we achieved snow depth estimates to decimeter accuracy when using a PPK enabled VTOL RPAS. This level of snow depth accuracy can provide valuable insight to guide avalanche control decisions. Additional aims are facilitating remote inspection of avalanche events (e.g. the crown line in the start zone) and estimating the volume of the debris post avalanche. The data is visualized and shared through a custom developed online portal.
A DEM of an avalanche chute covering 1.2 km vertical distance and 2.0 km horizontal distance (left column). Right column, shows a 3D view of the orthomosaic of the top of the chute (top panel) and details of structures (centre panel). An example of snow depth in a grid is given in the right bottom panel.