Monitoring of avalanche prone locations and using a modern system for controlled avalanches
The area below the peak Todorka in the National Park Pirin is characterized with steep mountain slopes and abundant snow precipitation. A recent study undertaken by a team from the Forestry University in Sofia looked at the avalanche activity on the north-western slope of peak Todorka and its influence on forests. They discovered that 7% of the forests were destroyed by avalanches repeatedly or during the last 50 years. The avalanches shaped out the structure and the composition of the ecosystem, affecting primarily the stationary species growing above the average snow-depth, such as trees and high shrubs. This in turn affected indirectly the small plants, the animals and the insects. To tackle with the problems created by the avalanches the administration of National Park Rila recently implemented a system for control of avalanches on the west slope of peak Todorka. The system consists of four exploders (tubes) positioned in avalanche starting areas and connected by pipelines to a central gas unit (shelter or mini-shelter). The avalanches prone area is monitored on a 24/7 bases from the office of the park administration. The high-resolution cameras and sensors on the spot provide the experts with real-time information about the thickness of the snow cover, the temperature and the moisture of the snow. If the data indicate a potential for an avalanche, the system automatically activates the explode automatically activates the exploders placed on the dangerous slope.
A system including monitoring sets and four exploders may cost between 1 and 1.5 million euro depending on the complexity of the terrain and the remoteness of the area. The funds can be provided by the operating programmes of the European Union or the budget a particular region.
Evidence of success
The system was implemented by the administration of National Park Pirin 5 years ago. Up to now there were more than 500 controlled avalanches. It is reported that more than half of the damaged areas, including formations of Siberian juniper (Juniperus sibirica) included in the Red Book, Chamaecytisus (Chamaecytiseta absintioides) also incl. in the Red Book, and Cranberries (Vaccineta vitis-idaeae) were recovered.
No challenges were encountered during the implementation of the system.
Potential for learning or transfer
The implementation of an avalanche monitoring system is used for a long time. The particular technology used in the Pirin park provides for ecological solution of the problem while in the same time guarantees safe use of the exploders, on time activation of avalanches and very effective results.