Embedded Files
Snow Avalanche Risk Management Framework. Adapted from Technical Aspects of Snow Avalanche Risk Management─Resources and Guidelines for Avalanche Practitioners in Canada (C. Campbell, S. Conger, B. Gould, P. Haegeli, B.Jamieson, & G. Statham Eds.). Revelstoke, BC, Canada: Canadian Avalanche Association 2016.
Purpose and Need
Purpose and Need
Terrain catalogs are built to aid in terrain identification and are compiled during the planning phases of operational risk management. Map creation and photo taking can also occur during operations and then be assembled as needed to augment the catalog overtime. A large mechanized guide operation’s catalog may take years to complete in order to account for every zone in a tenure. A highway avalanche atlas or ski area route catalog will look quite different and focus on specific paths and starting zones that affect the element at risk. An avalanche education provider might find it useful to include specific teaching areas in their catalog where a group can be stationary for long periods of time. This is similar to the way a public utility might manage a worksite for employees who need to repair a piece of infrastructure. The catalog is used during operational meetings to assist with terrain selection for a given day’s objectives and appropriate coding is assigned to specific runs or zones.
At the end of this section, there is a Terrain Catalog Exercise to assist you in creating a terrain catalog entry based on route, run, or slope scale descriptors.
Catalog Content
Catalog Content
Maps let you easily see things like big-picture avalanche terrain, aspect, elevation bands, distances and maybe some limited insight into vegetation.
Multiple photos from oblique angles allow for analysis of slope scale features like smaller terrain characteristics plus vegetation and potential terrain traps, in addition to giving you a more specific idea about where avalanches have run.
The creation of a robust catalog is aided by the proliferation of digital tools to complement photos. This is done from a desktop and can then be further ground-truthed during field operations. Google Earth and websites like GaiaGPS and Caltopo offer myriad tools and can interface with each other to create high-fidelity products for operational use.
Common terms you will come across during your exploration and creation of a catalog:
Route: A line that you draw on a computer that is based on where you think an uptrack, access road, or ski run might be likely to go.
Polygon: A shape you draw on a computer that defines a zone or area of where you might go or play. It can also show the boundaries of a known avalanche path.
Track: a real-world recording of where you went as tracked by a GPS unit like a watch, phone or handheld.
.GPX file: A common file type for tracks and routes that is used by GPS software .
.KML file: A common file type for tracks, routes, and ploygons used by Google Earth
A slope angle shading function commonly found on these applications can aid your route planning to compare the steepness of various slopes and help to identify what is avalanche terrain and what might be avalanche-resistant terrain. While slope angle shading is an excellent tool for planning it should never be used as an absolute for decisions when it comes to choosing what is and what is not avalanche terrain. Different digital elevation models, mapping errors and smaller features that are still steep enough to slide can be "hidden" within the contour lines. Slope shading tools also tend to underestimate slope angle. Use the shading as a guide and update your maps with notes of anything you ground truth. Never rely on digital tools to eliminate all of the terrain uncertainty before going out. Leave enough of a margin to be able to reduce the uncertainty through on the ground verification. Avalanche fatalities have been associated with people putting too much trust and weight into slope-angle shading and satellite imagery to preview terrain.
Terrain Catalog Excerpt Examples
Terrain Catalog Excerpt Examples
Guiding operation topo map and photo with runs and names indicated.
Ski area route list using Google Earth and photo to indicate paths and shot placement.
Guiding operations using Google Earth polygons to delineate zones for ski touring or snowmobiling.
Avalanche atlas with photo and topo map indicating paths that affect the highway.
Education provider using terrain imagery and topo to indicate teaching areas.
Terrain Catalog Exercise
Terrain Catalog Exercise
There are times when it is helpful for the terrain cataloging to be done at a detail that describes key features and characteristics of a slope, path, route, or run.
Download the Terrain Catalog Worksheet and print it off. Use the checkboxes to indicate when a route, run, or path meets one of the criteria listed for elevation, aspect, and slope scale descriptors.
Download, or open the Terrain Catalog Exercise Materials and use the photos and maps to assist you in filling out the worksheet.
The worksheet can be saved in your library and used in any setting. You can use the Answer Key below to check your work after you complete the exercise.
Terrain Catalog Worksheet_20211014.docxTerrain Catalog Worksheet
Terrain Catalog Worksheet
PRO Terrain Catalog Exercise.pdfExercise Materials
Exercise Materials
Terrain Catalog Worksheet_20211014_Answer Key.pdfAnswer Key
Answer Key
Operational Area Considerations
Operational Area Considerations
During the PRO 2, you will be asked to develop a small operational area (mountain to drainage scale). This flows forth naturally from the terrain cataloging component of the course. Students will be given parameters for the development and provided a context for the operation (motorized, human-powered, ski area, etc). This will be a combination of desktop work, using mapping software such as Caltopo and/or Google Earth, and field work where the course will visit the terrain, gather photos, and other important information. The following is an example of one deliverable that could be used for the assessment component, where students consider their collection of materials and map out specific features of the mock operational area. Using the slider, you can swap the maps that show elements such as emergency access, ATES segmentation, weather stations, and infrastructure.
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