Geomorphological conditions of snow avalanches in the Tatra Mountains

摘要

Snow avalanches are substantial processes of the natural environment and the denudation system in high mountains, with their activity depending on topoclimate, relief and snow conditions. The aim of the present research was to recognise the geomorphological conditions for snow avalanche activity in the Tatra Mountains by analysing the relationship between relief and avalanche path features for the area encompassing the whole of the massif both the Polish and Slovak parts of the Tatras. Maps of snow avalanches that occurred in the recent past, aerial photos and a digital terrain model were used to make a map of avalanche paths, with the starting zone, avalanche track and accumulation zone specified within each snow avalanche path. For each type of designated unit of snow avalanche track, a morphometric analysis was performed, taking into account slope aspect and inclination. More than 3,770 avalanche paths were identified whose number, morphometric features and altitudinal range differ between individual parts of the Tatra Mountains, corresponding to relief. The length of avalanche paths reaches up to 3,138 m, with paths located about 200 m higher in the High Tatras than in other parts of the massif. The average area of the starting zone in the High Tatras is half the size of that in the Western Tatras, while the number of accumulation zones is double the size. Based on a statistical analysis, the interrelations between slope exposure, slope inclination and length of avalanche path, as well as size of starting zones, were established. It was found that the length of avalanche tracks and the size of avalanche starting zones both decrease with increasing slope inclination.