Catastrophic Debris Flow Hazards in Chile: The Case of the 2004 Flows in Lago Ranco
by
Sergio A. Sepúlveda
Departamento de Geología, Universidad de Chile, Chile
Coauthors: Sofía Rebolledo and Rodolfo Toro (Departamento de Geología, Universidad de Chile, Chile)

On 28 August 2004, around a dozen debris flows were triggered by heavy rainfall in a lapse of few hours in the Andes foothills next to Ranco lake, in the Southern Chile province of Valdivia. The event caused one fatality and significant damage in rural houses and several roads, including the recently inaugurated tourist “Lakes Route”. Although the level of damage was not extremely high due to the absence of large urban areas and because the flows took place in the low tourist season, their recurrence observed in Holocene deposits suggest that they pose an important hazard. For this reason, a hazard assessment of the area is now being conducted.

Much of the damage could have been prevented with appropriate land use planning and road design. This is a recurrent problem in Chile despite catastrophic debris flow events in the cities of Antofagasta and Santiago in 1991 and 1993, which caused dozens of casualties. A review of these cases and discussion of the impacts of debris flows in the country is presented.

Date received: November 22, 2004

Copyright © 2004 by the author(s). The author(s) of this document and the organizers of the conference have granted their consent to include this abstract in Atlas Conferences Inc. Document # caod-45.