Oversair

An overburden is a sediment transport in mountain rivers (torrents) with an often area-wide deposition of solids (stones, rubble, coarse rubble and debris flow material ) outside the channel . Over-surfing occurs only in dynamic floods in sloping terrain with high flow speeds, so that the water can also transport larger stones. In addition to the channel, the high flow velocity also creates great erosion and high drag force . The stream often breaks out of its channel due to a blockage or insufficient drainage capacity. The material is usually deposited in the area of alluvial cones , where the flow rate decreases again. An over-solar system occurs after heavy rainfall and lasts only a few hours.

Some of the rubble is deposited according to grain size. The grain size decreases with increasing distance from the exit point.

One example is the Übersarung of 1831 on the Lütschine .

Web links

• Natural hazards glossary
• Documentation of natural events, p. 20 (PDF file; 3.03 MB)