Abstract
The avalanches represent a significant and very dynamic process within the Tatra high-mountain landscape. Undoubtedly avalanche run-out distances play a key role in land use planning within avalanche prone areas.
The Ziarska valley in Western Tatra Mts. and PrednE Medodoly valley in Belianske Tatra Mts. are considered as one of the most avalanche prone valleys in the whole area of Carpathian Mountains. This environment represents an excellent opportunity for studying and modelling extreme avalanche run-outs.
The valley is frequently visited by backcountry skiers and several roads and cabins are located there as well. This requires a detailed land use planning with regards to the extreme avalanche run-out.
Primarily avalanche release zones were estimated by using an existing model proposed by Hresko (1998). This model was modified and calibrated with the use of avalanche data extracted from a database maintained by Slovak Centre for Avalanche Mitigation.
The alpha-beta regression model developed in Norway has been used to estimate avalanche run-outs. This model is calibrated for use in Western Tatra Mts. and Belianske Tatra Mts.
Topographical parameters from well known extreme avalanche paths have been collected using GPS. Data processing and model calibration have been elaborated in geographic information system (GIS) environment.
Avenue script for ArcGIS was written to perform automated run-out estimation based on alphabeta regression model. Model managed to estimate run-outs on some slopes while it failed to model run-ups.
Finally the results were visualized by creating the fly-through simulations and 3D views. Winter season 2008/2009 with disastrous avalanches showed the importance of avalanche run-out modelling.
Numbers of installations have been damaged due to improper land use planning without respect to extreme avalanches. Comparison between model calculation and avalanche cadastre showed correlation.