Definition of Technical Term

Other Countries

Landslide dam

Landslide dam is formed by hillside landslides, rain, earthfall caused by earthquakes, landslides, debris flows and other circumstances. At times, it is also formed by a massive outwash from a main river to a tributary river.

When a landslide dam is formed, it yields an extreme amount of sediment, potentially causing extensive damage.

Therefore, if a landslide dam is formed, the first priority is to calculate the scale and kind of possible damage and establish proper countermeasures.

Generally speaking, the cause of a failure of a landslide dam is thought to be an overflow or piping. Emergency measures include founding a diversion tunnel, draining by pump, installing a cutoff, installing groundsill (a block, etc.) and other bed wall(s) to prevent downstream scouring, levee heightening in lower reach, and clearing debris from the sabo dam in the lower reaches.

Translated from Journal of Japan Sabo Association, Sabou to Chisui, Vol.163, pp.85, 2005