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Rockfall hazard zones in Austria. Experience, problems and solutions in the development of a standardised procedure
Author(s) -
Mölk Michael,
Rieder Benedikt
Publication year - 2017
Publication title -
geomechanics and tunnelling
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.317
H-Index - 18
eISSN - 1865-7389
pISSN - 1865-7362
DOI - 10.1002/geot.201600065
Subject(s) - rockfall , outcrop , natural hazard , geology , human settlement , hazard , settlement (finance) , hazard analysis , stage (stratigraphy) , mining engineering , geography , geotechnical engineering , geomorphology , landslide , computer science , engineering , archaeology , paleontology , chemistry , organic chemistry , oceanography , aerospace engineering , world wide web , payment
The Österreichische Raumordnungskonferenz (ÖROK) set up a partnership in 2011 to deal with ”Risk management for gravitational natural hazards in landuse planning“. As gravitational natural hazards have a decisive influence on development in the Alpine Region, standard procedures were developed for the assessment of the relevance of these processes for landuse planning. This paper describes the recommended procedure for the assessment of hazards affecting permanent settlements from rockfall in a top‐down approach. The first step to define potential conflicts between the maximum run‐out of rockfall processes and the presence of settlements is a conservative empirical assessment based on rock outcrops serving as potential detachment zones and the maximum reach of such rockfalls, leading to a hazard indication map. This approach is only based on existing cartographic information, field investigations are not necessarily involved at this stage. To ensure conservative results, the use of a high‐resolution 1 m ground model to identify rock outcrops is re commended. The next step includes a thorough examination of those areas in the hazard indication map with conflicts between the maximum reach/run‐out of falling blocks and settlements. This stage includes field investigations with mapping of maximum reach blocks, block size distributions, underground conditions of the transit zone and the condition of rock outcrops that act as potential detachment zones. All this information is subsequently integrated into a 3D rockfall simulation. As a result the modelling enables a delineation of areas out of reach (no rockfall hazard), areas with potential impact energies ≤ 100 kJ (low intensity) and areas with potential impact energies > 100 kJ (high intensity).