SPATIAL MODELLING OF AVALANCHE HAZARD IN THE BORZHAVA MOUNTAIN MASSIF USING QGIS TOOLS

Abstract

Snow avalanches represent one of the most significant natural geomorphological hazards in the Carpathians, posing a direct threat to tourism, transport infrastructure and human safety on mountain slopes. The Borzhava mountain massif, a popular recreational area in Zakarpattia Oblast, is characterised by considerable elevation, extensive open subalpine meadows (polonyny), and intense winter tourism, all of which necessitate detailed avalanche hazard zonation. The study aims to assess comprehensively and spatially model avalanche hazard across the Borzhava massif by integrating morphometric relief parameters and land cover characteristics using GIS technologies. Digital elevation models SRTM and ASTER GDEM (30 m resolution) and multispectral Landsat 8/9 satellite imagery were used as primary data sources. All processing was performed in QGIS 3.x using the GDAL/Processing module and SAGA module. Five key morphometric factors influencing avalanche formation were analysed: absolute altitude, slope steepness, aspect, plan curvature, and profile curvature. Land cover type was classified using the ISO Cluster Unsupervised Classification algorithm (QGIS/GDAL) from Landsat imagery using the Spatial Analysis Toolbox plugin. Each class of each factor was assigned a weighted avalanche hazard coefficient (0–3). An integrated risk index was computed using a multiplicative formula that accounts for the additive contribution of morphometric parameters and the amplifying role of slope steepness and surface roughness. The highest avalanche hazard is concentrated in the ridge-crest zone above 1,400 m a.s.l., where steep slopes of 30–45°, southern aspects, and absence of forest cover coincide. High-hazard zones cover approximately 15 km2 (4 % of the massif area), while safe and low-hazard territories account for over 80 %. Forest stands act as a key natural stabiliser of snow cover, substantially reducing risk on lower slopes. The results are consistent with dendrochronological reconstructions of avalanche activity in adjacent Eastern Carpathian massifs and confirm the effectiveness of GIS-based modelling for preliminary avalanche zonation in the mid-mountain terrain of the Ukrainian Carpathians. The produced maps can serve as a scientific basis for adjusting tourist routes, restricting access to hazardous zones during winter, and justifying engineering protection measures.