SEDIMER - Sediment-related Disasters and Hazards following the 2010 centennial eruption of Merapi Volcano (Indonesia)

We all know about the destructive power of volcanoes, yet did you know how much damage a simple word like Lahar can carry? Most widely used in Indonesia, it first described water-saturated mass flows of volcanic debris before being applied as a general term for rapidly flowing, high-concentration, poorly sorted sediment-laden mixtures of rock debris and water from a volcano.
Because they pose a constant threat to downstream villages and towns, lahars are one of the most destructive phenomena associated with composite volcanoes all around the world. What is more, despite their regular occurrence, the behavior and propagation of rain-triggered lahars are poorly understood, thus impeding any consistent assessment of their political and socioeconomic costs for local residents. Yet, that was before Prof. Lavigne set out to study one of the most active volcanoes in the world: Mt. Merapi in Indonesia.
Indeed, due to a devastating eruption in 2010, it is now crucial to determine what may happen in the next five years to the river valleys downstream from Mt. Merapi. Prof. Lavigne and his team are seizing this unique opportunity to compile a database on lahar occurrence thanks to a collaborative and multi-disciplinary study gathering experienced international experts and young scientists from seven countries including Indonesia. Their innovative methods rely on a combination of high-tech instrumentation and socioeconomic calculations to model and quantify the impact of lahars on local populations.
Thanks to this integrative approach, Prof. Lavigne seeks to obtain a comprehensive understanding of the occurrences and impacts of lahars with results which may immediately be used by policy makers for land use and emergency response planning. Eventually, his work might help reduce exposure and improve the resilience of local populations to threats from lahars.