Measures to counter debris flow
The following measures avert or reduce the danger of debris flow:
- Avoid the vicinity of mountain torrents during spells of heavy precipitation. Note: debris flows can affect the areas along a channel as well as the channel itself!
- Be familiar with safe places and escape routes that are suitable for use during flood events (raised ground at a safe distance from the channel).
Technical / biological measures
- Streambed protection by means of torrent check dams, debris retention basins, diversion dikes and debris flow breakers.
- Protection forests can reduce the supply of debris into watercourses over large areas. On the other hand, if trees near to the banks get into the stream channel they can be the cause of debris jamming, contributing to triggering debris flow.
Spatial planning measures and object protection
- Install higher entrances.
- Avoid windows around deposition height.
- Use strengthened construction components to withstand impact (e.g. reinforced concrete).
- It is very difficult to have advance warning of debris flow, as precipitation events may or may not lead to the formation of debris flow for the same torrent. There are only a few minutes between the triggering of debris flow and its arrival on the mountain debris fan.