OA2035. Rockfall hazards in Austria’s hiking network: A GIS-based spatial risk assessment

Abstract Issue/Problem Austria’s hiking network is increasingly affected by rockfall hazards, especially in areas with unstable geological conditions. These hazards pose a significant risk to hikers, contributing to injuries and fatalities. The ongoing effects of climate change, such as the thawing of permafrost, potentially increase the risk, making it more critical to assess and address rockfall dangers. Description The Austrian Road Safety Board (KFV) investigated the extent of rockfall risks across the hiking trail network in Austria. A GIS-based environmental data analysis has been employed to assess regions prone to rockfalls. A combination of OpenStreetMap data for hiking trails, hazard zone mapping, digital elevation model, and weather-induced hazard events was used to create a risk estimation model. By combining these data layers, the analysis highlights areas of potential rockfall risk and therefore allows risk identification and spatial mapping of hazardous areas along the hiking network. Results The findings show that over 760 kilometers of Austria’s hiking trails are located in areas classified as having high rockfall risk. These zones are especially concentrated in alpine regions above 1,500 meters, where unstable geological formations and increased exposure to weather extremes, such as heavy rainfall and freeze-thaw cycle, amplify the hazard potential. Between 2019 and 2023, an average of 61 injuries and 3 fatalities per year were linked to rockfall incidents, highlighting a persistent and serious threat to recreational trail users. Lessons The results underscore the need for a comprehensive follow-up analysis to systematically overlay the identified risk zones with existing safety infrastructure. This step is essential to determine the actual hazard exposure, identify critical trail sections where mitigation is lacking, and prioritize future safety investments. Key messages • Over 760 km of trails are located potential rockfall risk areas, with incidents causing injuries and fatalities. • The KFV report highlights that rockfall incidents predominantly occur at higher altitudes, particularly in regions above 1,500 meters, where the combination of unstable geological conditions and climate change-induced weather events, such as thawing permafrost, increases the risk. The report emphasizes the importance of using risk assessment tools like R.A.G.N.A.R. to better understand these hazards. Topic Rockfall risk, Hiking safety, Natural hazard events.