Zoning of snowiness and avalanching in the mountains of western Transcaucasia

Abstract

AbstractIn the mountains of the moist-subtropical zone of Western Transcaucasia seven zones of snowiness are distinguished, depending on the heights from sea level to the tops of mountain ranges. Data are taken from 17 years of snow-avalanche observations. In a legend of a map the quantitative characteristic of the avalanching conditions for each zone is given. Interannual variability of snow depth is up to 100 cm in low mountains and about 600 cm in the middle belt of mountains The inversion of snow accumulation is registered. The frequency cycles of heavy-snow (3–4 years) and of especially heavy-snow (10–12 years) winters are determined. The avalanche danger is provoked not by the total depth of the snow, but by the stormy snowfalls. The particular conditions of creation and development of nival processes are distinguished here: dry avalanches on the crests of mountains, wet avalanches in the middle mountains and slushflows in the low mountains. Despite low avalanche activity, avalanche risk is high due to the factor of unexpectedness.