Snow Avalanche Hazard Mapping for Different Frequency Scenarios, The Case of the Tatra Mts., Western Carpathians
Abstrakt
Snow avalanche hazard mapping is an important tool for land-use planning and safety assessment. It has proven to be the one of the most efficient and the most cost effective hazard mitigation measures.
This study represents a fundamental shift from past research, which has focused on large catastrophic events. Small to medium scale events are more frequent and therefore pose constant and persistent problems to hazard mapping experts.
Based on historical databases and investigations of small and medium scale avalanches, we found new solution strategies to hazard mitigation problems that are now typically solved by evaluating a "worst case" scenario. "Worst case" solutions can be applied when analyzing catastrophic events, but lead to cost-inefficient results for frequent avalanches. First of all, the study describes a new automated approach for the delineation of different frequency avalanche release areas, which seems to be the crucial step in avalanche hazard mapping process.
Based on climatological data from Polish and Slovak meteorological stations we calculated potential fracture heights for different frequency scenarios. This information, combined with generated release areas, was the main basis for calculating potential avalanches' volumes.
Dynamic calculations were prepared using Swiss RAMMS system, implementing the standard Voellmy-Salm (VS) approach. The results of new hazard mapping procedures were confronted with historical avalanches extents of different return period and scale, mapped in both Polish and Slovak areas of the Tatra Mountains.