Global losses from landslides associated with dams and reservoirs

Abstract

The 1963 Vajont disaster represents by far the largest landside-related accident associated with a dam or reservoir in recorded history. Since then, those involved in planning and constructing large dams and reservoirs have taken measures to ensure that this event is not repeated. In general this has been successful, with no events with losses on a similar scale. However, landslides have continued to present a substantial challenge to those involved in the design and construction of large dams. In the first part of this paper, a brief review is provided of the impacts of landslides on dam projects, highlighting that although losses of life from landslides on reservoir banks have been low, mass movements have frequently caused problems for dam foundations and abutments. Unidentified landslides or areas of potential instability have required very expensive mitigation works when identified after dam construction had started, and they have caused substantial environmental impacts. The second part of this paper examines losses of life from landslides associated with dams and reservoirs in the period 2003-2012 inclusive. It is shown that during this time 500 lives have been lost in landslides associated with dams and reservoirs in 37 separate events. Almost all of these landslides have occurred in East and South Asia, with the majority affecting India and China. These landslides have mostly killed people involved in the construction of dams, either at construction sites or in landslides affecting workers’ accommodation. In the mountainous regions of Asia, a very large number of dam construction projects are proposed, planned or under construction. This suggests that losses will continue to rise in the years ahead unless substantial measures are taken to address the causes.