Large Avalanches in Forested Terrain in Pirin Mountains – Tree-ring and Numerical Simulations Analysis

Large avalanches in forested terrain occur more frequently and with greater magnitude in the Pirin Mountains, Bulgaria, than previously understood. Analysis of over 700 tree-ring cores reveals that these events have struck almost every decade, with widespread occurrences during the mid-20th century. Despite a perceived reduction in frequency in recent decades, deadly avalanches still pose significant risk, as demonstrated by the 2015 event near Yavorov Chalet. Numerical simulations using RAMMS::EXTENDED indicate that such avalanches could match the scale of historical damage, with parameters aligned to 100-year return period dry snow avalanches. This challenges the assumption that forested areas are inherently safer, underscoring the need for better risk assessment and protection strategies in regions like Pirin National Park, where tourism and endemic forests intersect.

Panayotov, M., Tsvetanov, N., Kotova, V., Balov, V., Bühler, Y., Bartelt, P., & Bebi, P. (2026). LARGE AVALANCHES IN FORESTED TERRAIN IN PIRIN MOUNTAINS – TREE-RING AND NUMERICAL SIMULATIONS ANALYSIS. Proceedings of the International Snow Science Workshop 2026, 1090–1098. https://doi.org/10.15788/1790098515