Artificial Avalanche Release above Settlements

In the Swiss Alps avalanche control with triggering by explosives is widely used in ski areas and also along traffic routes. New methods for artificial avalanche release have been developed during the last years. Autonomous devices allow remote triggering of avalanches independently of visibility and with a good detonation effect. In Switzerland the standard methods for protecting settle- ments are snow supporting structures and earth dams. Some endangered settlements or group of houses still have no protection with structural defence measures due to high costs. At some of these locations, artificial avalanche release has been applied successfully since the 1950s. Local avalanche control services are interested in improving the safety measures. Therefore the application of artificial avalanche release for the protection of settlements is also discussed for new locations. In general, artificial release above settlements should be applied with extreme caution and should remain an ex- ception. The main risk of artificial release above settlements is triggering a too large avalanche caus- ing damage. For such applications the avalanche situation must be studied in detail. Important points are the evaluation of the terrain features in regard to the effectiveness of artificial avalanche release, the potential for triggering secondary avalanches and the existing damage potential. We developed a technical guideline which defines the most relevant factors for evaluating the safety aspects.