Approaches to Multi-Hazard Landslide Risk Assessment: Fid-Bau Portal

Approaches to Multi-Hazard Landslide Risk Assessment

Zhang, L. M. / Zhang, S.

Assessment of multi-hazard risk is a new area being explored recently. This paper provides a brief review of approaches to multi-hazard landslide risk assessment and discusses several key issues in such assessment. We illustrate the importance of hazard interactions through several examples of cascading landslide events, and review the methodologies to include hazard interactions in multi-hazard risk assessment. Multi-hazards prevail in landslide events. Rock falls, topples, soil or rock slides, debris flows, landslide dams, and dam breaching may occur when triggered by an earthquake or a storm. One initiation event can trigger one or several hazards; the interactions among these hazards may generate additional tertiary hazards. The vulnerabilities of the elements at risk to these hazards are also closely related. The vulnerability may come to a break point when several hazards compound. Conventional risk assessment deals with each type of hazard separately and the total risk is taken as the sum of all the individual risks. The interactions among the multiple hazards and the impact of the presence of one hazard on the vulnerabilities to other hazards are often not considered. Such assessment is obviously inadequate. New multi-hazard risk assessment methods including hazard or vulnerability interactions have been proposed. Yet efforts must be made to quantify the physical mechanisms and processes of such interactions within the life cycle of the hazards. A systematic approach is needed for multi-hazard mitigation, which is an emerging topic.