Determination of thresholds at the Aggenalm landslide (Bayrischzell, Germany) by time series analysis and numerical modeling

Within the framework of the alpEWAS project the Aggenalm landslide has been instrumented with a monitoring system, which monitors the slope's deformation as well as potential trigger factors, such as precipitation. All data collected within the project have been evaluated and interpreted holistically in terms of integration into an early warning system and the thereby accompanying definition of thresholds. Since it became clear that rainfall has a major influence on the slope's movements, the temporal offset between rainfall, pore water pressure, and increase in deformation has been analyzed by time series analysis. This made it possible to quantify the needed advance time for early warning between triggering event and movement of the slope. To analyze the slope's reaction to rainfall events beyond the ones observed so far, a numerical model was generated to simulate extreme events, thus allowing a better definition of threshold values for early warning.