Harvey, S., Rhyner, H., Dürr, L., & Henny, H. M. (2018). To go or not to go: decision making at individual slope. In International snow science workshop proceedings 2018 (pp. 1346-1350).
The holistic assessment and decision framework «3 x 3» is well established for ski and snowboard tours. Whereas difficult decisions can be postponed in the first two filters, «planning» and «local evaluation», a final decision is necessary in the third filter «individual slope». At that point, we can only decide 'to go' or 'not to go'. So far, an approach asking the right questions and answering them systematically was missing. The latest edition of the popular leaflet «Caution Avalanches» now includes a risk-based scheme for decision making at the individual slope. Three elements of avalanche risk assessment are considered: the avalanche triggering probability, the consequences of being caught and the behaviour, i.e. measures to reduce the risk. Three colours (blue, pink and orange) corresponding to the three elements guide the user through the decision-making process. In a first step, important questions have to be asked related to each of these topics. The answers can then visually be combined with the help of a diagram to estimate the avalanche risk. The scheme suggests an explicit decision 'go' or 'no go' and helps not to forget anything essential. In addition to the established methods, such as the «graphical reduction method» or thinking in «avalanche problems», the presented tool is an aid to reflect important factors for making decisions at the individual slope. It especially applies to slopes steeper than 30° and to slopes that are either not obviously critical or unproblematic. We demonstrate how to apply this risk-based approach to make better decisions at the individual slope.