PERMANENT PROTECTION AGAINST SNOW AVALANCHES – SUCCESS OF MEASURES ABOVE AC HRUŠICA – VRBA (1993-2005)

Abstract

The threat of snowslides is in general underestimated in Slovenia, and very much underestimated in connection with the threat to traffic. According to a study, Risk Assessment of Slovenia from Snowslides, commissioned by the Protection and Rescue Agency RS and the Ministry of the Environment and produced in 1990 by Podjetje za urejanje hudournikov, at least 89 snowslides threaten main roads, at least 275 threaten regional roads and at least 303 threaten local roads. Protecting the motorway section Hrušica-Vrba pod Mežaklo is the largest example of integral protection from snowslides in Slovenia. The winter of 2005/06, when the height of the snow cover came very close to the maximum envisaged by antiavalanche measures, was very suitable for assessing the effectiveness of the system of protection from snow avalanches with anti-avalanche objects. Data were used in the analysis from the closest meteorological station of Planina pod Golica. Despite the highest by far recorded intensity of snowfall in this region and above average maximum levels of snow cover, the system of protective measures functioned as a whole according to expectations. No snowslides were triggered in the area of roads. In addition, there was fairly intensive overgrowing of objects of protected avalanche slopes. Traffic on the Hrušica-Vrba motorway, according to current knowledge and findings on conditions on the ground, is protected from snowslides, but nevertheless the constructed system of anti-avalanche support objects must be monitored and supplemented as necessary. After intensive winters, such as the winter of 2005/2006, urgent maintenance work must also be carried out.