Research Progress on Rapid Hazard Assessment of Landslide Dams Caused by Landslides and Avalanches

Landslide dams usually formed by river blockages with massive amounts of materials from avalanches, landslides caused by earthquake, rainfall, and volcanic eruption. The formation and breaching of landslide dams caused by landslides or avalanche normally have characteristics of sudden occurrence, sudden breach and high risks, posing great threats to people and infrastructure upstream and downstream. The study of rapid hazard assessment of landslide dams is of great significance for emergency risks management. At present, rapid hazard assessment of landslide dams mainly focuses on four aspects, i.e., the possibility of dam formation, stability, longevity, and breaching flood. This paper first reviewed the influencing factors and efficient discriminant formula study of landslide dam formation. Then, the definition, affecting factors and rapid evaluation model of the stability and longevity of landslide dams were specifically summarized. Finally, the failure modes, affecting factors and quick prediction models of dam breaching flood were analyzed in detail. The present research showed that the formation of landslide dams was mainly affected by the topographic conditions, solid material sources and water sources, and the stability, longevity, and breaching parameters were mainly influenced by the geometrical characteristics, materials, structures, and hydrological characteristics of landslide dams. The evaluation models based on the influencing factors can estimate the formation, stability, longevity, and breaching parameters quickly, but the accuracy of results still needs to be improved. On this basis, five directions are proposed for further research: 1) large-scale model tests on the occurrence and migration process of landslides or avalanches under different factors (e.g., earthquake, rainfall) should be carried out, so as to establish the rapid assessment model of dam formation; 2) new methods to obtain the dam materials and internal structural quickly should be studied; 3) prediction research on breaching degree of landslide dam should be carried out to analyze the risk of residual landslide dam; 4) quick assessment model of dam breaching flood should be established from the perspective of watershed to guide water dispatching and engineering construction; 5) dynamic risk assessment of the impact of disaster chain on the whole river basin should be carried out to provide important reference for disaster prediction and emergency treatment. © 2021, Editorial Department of Advanced Engineering Sciences. All right reserved.