Technical and Human Aspects of Historic Rockslide-Dammed Lakes and Landslide Dam Breaches

Abstract

The historical presentation of some 12 major landslide dam cases in the Alps which occurred between the first century AD and the present time, and for which significant information is available, allows the formulation of specific conditions which are generally met with respect to the development of the phenomena, their direct and indirect consequences on the population and the possible prevention and mitigation actions that can be carried out. Three major recent cases in Switzerland and South America, in which human preventive action was essential to save many lives and property, are then briefly commented, especially with respect to the need for timely and well-coordinated action by the Civil Defence, the Army and the local authorities, in order to avoid more dramatic consequences due to the formation and subsequent breaching of the landslide dam lake. This analysis points out the necessity of assessing the potential landslide scenarios and the related risks properly so as to limit the possible consequences of such dramatic events in the future.