Early detection system for avalanches and debris flows

 

　　

Measurement fence made from thinned wood from Akita Sugi          　　 　 Measurement sensor unit

 

sensor bracket

 

　　Under certain conditions, when weather and snow cover steep slopes, an avalanche occurs. It can reach protective fences. If a collapse of these fences causes an avalanche to occur and arrives at a roadway, then traffic would be hindered. Predicting the occurrence of avalanches is important, but it has not been implemented. To avoid and resolve difficulties caused by avalanche and debris flow hazards, we measured the snow pressure using the magnitude of the voltage to assess danger during a snowfall period at an avalanche protective fence. We developed a piezoelectric limit sensor and a piezoelectric vibration sensor for detecting avalanches by converting the avalanche load and vibration, as well as the pressure and shock received by the device as electrical signals. This measurement system is fixed with a dedicated mounting bracket so that pressure and vibration measurements related to snowfall at the time of avalanche occurrence can be measured at the main structural part of the avalanche defensive fence. In addition, this measurement fence is designed to withstand pressure imposed by 3–5 [t/m²] snowfall using wood supports.

 

 

Piezoelectric limit sensor

 

 

Mounting test of measuring fence (outdoor test)

　　A measurement fence was installed on the slope in the mountains of Noshiro City, Akita Prefecture.
For about a year and a half from a remote location, we continued to measure with the piezoelectric limit sensor.