In the municipality of Hörbranz, Vorarlberg, Austria, extensive rainfalls with a culmination on the 28th of April 2023 triggered a large‐scale, rapid moving landslide that destroyed a farmhouse and five residential buildings. Although a similar event has not been recorded in the past, geomorphological evidence suggests that the area must have been unstable a long time ago. The current slope movement represents a cascading process: Highly disintegrated and weathered soft rock from a rockslide in the upper slope reactivated an ancient mudslide in the lower slope including a total volume in motion of approximately 400,000 m 3 . The setup of a monitoring and exploration program significantly improved the understanding of the governing processes and provided essential insights into their mechanics. The hereby gained knowledge enabled to implement effective mitigation measures, which mainly aimed to reduce high pore‐water pressures. Through the implemented measures, the slope movements slowed down significantly, thus preventing the destruction of additional buildings.
Sausgruber et al. (Wed,) studied this question.