What are Lahars

Known to be one of the greatest volcanic hazards, lahars are the flow of debris or mudflow that are usually seen on slopes of a hill. Lahar consists of debris which may include rock fragments and water. The water content is usually high in lahar, and hence causes the debris flow. Lahar can be triggered by various causes. These causes that trigger lahar include -

1. Rainstorms which can cause debris of fragmented rock or mud to mix with flowing water.

2. Due to collapse of a debris dam or a landslide dam which may lead to catastrophic spillage.

3. Volcanic eruptions or volcanic landslides which may generate a debris flow of lava fragments, superheated gases and hot ash.

4. Avalanche which may cause a debris flow of water laden mud, soil, ice fragments and rock fragments.

Source - Google

Lahars travel at great speed up to 50 miles per hour. Since they travel downslope with great force, lahars can be considered to be one of the greatest hazards to life and property. Lahars are known to wipe out building, trees, roads, bridges, vehicles and barriers, since they travel at such great speed.

Few methods which are used to avoid major damage by lahar includes -

- Building of concrete structure.

- Detouring a lahar by constructing retention basins for collecting the mudflow.

- By creating alternate channels for the lahar to pass without maximum damage to property.

- By providing warning systems for precaution

- Evacuation.