Hofermühle Landslide Monitoring Site - Austria
Hofermühle Landslide Monitoring Site
The ENGAGE working group (Geomorphological Systems and Risk Research at the Institute for Geography and Regional Research, University of Vienna) has been running a long-term monitoring project to investigate landslides in Lower Austria since 2015 (NoeSLIDE project). Landslides play an important role in landscape development and can have impact on human life and property; in Lower Austria, landslides - especially sliding and falling processes - are concentrating in areas of respectively prone geology, namely the Flysch Zone (sliding) and the Northern Calcareous Alps (falling). Resulting from sporadic phases of activity it is essential to generate specific long-term measurement series, enabling the analysis of changes in both surface and sub-surface dynamics as well as potentially related triggering factors. The Hofermühle site is located in the district of Waidhofen a.d. Ybbs, Lower Austria. The site is located in the Flysch Zone, a geologically predestined zone known to be extremely prone to landslide processes in Austria. Within the 0.15 km² hydrological catchment of the Hofermühle torrent, landslide processes can be defined as complex, being constituted by shallow earth sliding in the middle and gently inclined part of the catchment nearby the torrent, accumulation of material and resulting earth flowing down the steepening torrent path. It can be defined as complex earth slide - earth flow, which has shown different phases of activity in the last 10 years on different parts of the landslide mass. Major activation occurred in 2011 (subsidence via sliding by 2 m in 2 weeks), re-activation in 2013 (formation of earth flow with 20m/h) and processes have slowed down significantly since then to only a few cm to dm per year on the parts affected by sliding – as far as known. To investigate both surface and sub-surface dynamics and potential interrelations, a varity of permant and individual measurement techniques are applied at the study site. Direct investigations include dynamic probing, percussion drilling and core sampling. Hydro-meteorological parameters are acquired via TDRs (time domain reflectrometry) probes, piezometers for groundwater estimation and a meteorological station (precipitation, temperature, snow height, wind, solar radiation). Sub-surface displacements are measured with both manual and automatic inclinometers. Surface dynamics are investigated via multi-temporal TLS (terrestrial laser scanning) and UAV-based SfM (unmanned aerial vehicle; structure from motion) data. Data from permanent installations is given in 5 min resolution (TDR, piezometer, meteorological station, inclinometer).
General Characteristics and Status