Лëд и снег (Sep 2021)
Performance evaluation of anti-avalanche measures at the «Krasnaya Polyana» ski resort
Abstract
For the first time, a qualitative and quantitative evaluation of the effectiveness of anti-avalanche measures was carried out for the territory of the «Krasnaya Polyana» ski resort, located in the Western Caucasus on the Aibga ridge. The following materials were used for this work: the results of field survey in 2019, which made it possible to map the resort's infrastructure exposed to possible snow avalanches and protected by existing preventive (anti-avalanche) measures, experience of similar studies from other regions as well as identification of the avalanche release zones by means of digital elevation model and analysis of remote sensing data, archive data on the snow avalanches regime at the site, and numerical modeling of the snow avalanches with different starting conditions. Modeling of the avalanches was performed in the RAMMS program basing on three scenarios: 1) taking account of the successful operation of existing anti-avalanche measures; 2) with regard for the failures in the work of existing anti-avalanche measures that were recorded earlier during the operation of the resort; 3) without considering any anti-avalanche measures, which corresponded to the conditions at the stage of the territorial planning of the resort. Differences in the impact of simulated avalanches on the resort infrastructure were interpreted as «high», «medium» and «low» effectiveness of existing antiavalanche measures. It was found that the dynamical characteristics of the local avalanches (run-out distance, volume, velocity, and pressure) had different importance for different types of the infrastructure with regard to the effectiveness of anti-avalanche measures. Under existing conditions of the relief, climate and vegetation of the investigated territory the artificial triggering (at the ski resort it is mainly made by the Gazex systems) is the most efficient. Snow-retaining structures often do not perform their functions, while dams and avalanche cutters can be successful only in combination with the properly functioning artificial triggering. It was found that there are areas where the run-out distance of artificially controlled avalanches is smaller than that of possible natural avalanches, and these areas can still be dangerous for the infrastructure of the resort due to the high values of the avalanche speed and pressure.
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