GIS-Based Rockfall modelling and risk-assessment in the low mountain ranges of Rhineland Palatinate, Germany

Geographic information systems are a valuable tool to assess the vulnerability of infrastructure posed by mass movements. Since 2014, the State-Geological Survey of Rhineland-Palatinate, Germany (LGB) recorded over 130 cases of rockfall and rockslides. Since only cases near vital infrastructure are recorded, the actual number is estimated to be much higher. The research presented here, makes use of the free to use algorithms of Q-, SAGA- and GRASS-GIS to create semi-automated workflows to identify endangered zones and infrastructure.  Based on high-definition LiDar-Digital Elevation Models Source Areas for the processes are calculated and used as start cells for Gravitational Path Models.  The start cells are calculated by looking for erosion contributing parameters such as exposure, insulation, surface runoff but also rock specific parameters like rock loosening and lithology. Through the precise identification of the rockfall source areas and further input data like vegetation and relief energy numerous cases exemplary in the area were modeled. Validation using the Mass-Movement Database of the Rhineland-Palatine Geological Survey and numerous ground checks show, that concrete rockfall events were simulated. By intersecting with real infrastructure data, it is possible to carry out risk assessments of specific sections of roads and railway lines. These coincide with the actual cases of damage and safety measures and can therefore be assessed as plausible and used for hazard zoning.