Reliability of GBInSAR Monitoring in Ingelsberg Landslide Area (Bad Hofgastein, Austria)

The present work shows and discusses the GBInSAR measurements for the Ingelsberg area, where one of the most dangerous landslide of Salzburg region is located (Bad Hofgastein – Austria). It is a rockfall developing on an area of about 40000 m2 which is characterized by the outcropping of anti-dip stratified green and calc-mica schists. The GBInSAR monitoring campaign started on March, 2013 (scan time of about 5 minutes): data acquired by the radar instrument were integrated with those from other traditional monitoring systems consisting in 3 cameras placed near the slope and 5 extensometers placed in the landslide Head Area. In order to evaluate the reliability of GBInSAR monitoring, a comparison with displacement data from extensometers was made. During March-December 2013 at least 5 events were observed, the main of which occurred during April-May-June period (3 events), representing a key period for the landslides occurrence in this region. Taking as reference this period, the comparison of the two monitoring techniques showed a good correlation, indicating that the monitoring system of the Ingelsberg landslide is reliable and useful for further analysis, such as the application and checking of the techniques to predict the time to slope failure (TSF).