Preonzo, Switzerland: In Preonzo, Switzerland, local authorities used Leica Geosystems’ Deformation Monitoring solution GeoMoS to save several lives. On May 14, 300,000 m3 of rock broke off the Valegion mountain and crashed down 1,000 m to the valley floor. Local authorities used GeoMoS to evacuate the valley’s industrial zone and to close the A2 highway and several cantonal roads at an early stage.
The Cantonal Forestry Office has been watching the danger zone since 1998, and has been relying on automatic monitoring systems from Leica Geosystems AG for the past two years. Cantonal geologist Giorgio Valenti said, “We have regularly experienced small movements over the years, especially in spring time. Since the end of April of this year, the movements measured have increased to several millimetres per hour, which made the safety measures necessary.”
The automatic monitoring system provided continuous information about every movement in the affected zone. Two years ago a Leica TM30 Monitoring Sensor was installed on a stable pillar below the slide area and connected to the Leica GeoMoS monitoring system. Since then the sensor has monitored 15 observation points located inside and outside the danger zone every hour, 24/7. The results are automatically forwarded to an FTP server in the Forestry Department and then analysed by experts.
The experts were kept informed by SMS about the movements. As their speed continued to increase, it became clear that the rock would soon break off.
Source: Leica Geosystems