Influence of dam and erodible bed material composition on landslide dam failure and induced morphological changes: an experimental study
(2024) Bulletin of Engineering Geology and the Environment — Vol. 83, n° 2, p. 21 (2024)
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- Abstract
- Landslide dam failure and induced morphological changes are dependent on the material composition. A bimodal material composition is observed in landslide dams and riverbeds, but its influence on dam failure and morphological changes is poorly understood. In this study, we experimentally investigate landslide dam failure and its effect on local morphology by varying both dam and bed material composition. The results show that the peak discharge and final breach size increase, while the upstream residual water level decreases with increasing fine material (sand) content in the dam material. The effect of the bed material is limited and the whole dam failure process is rather controlled by the dam material. However, erosion surface slope and final erosion depth vary with changes in both dam and bed material. Sediments are deposited unevenly on the erodible bed, resulting in the formation of sandbars after dam failure. Similar topographies are observed with different erodible beds, while the deposition area and the anisotropy of deposition depth increase with increasing sand content in the dam material. The influence of bimodal material on dam failure and morphological changes is related to the incipient motion and transport of sediments, leading to the formation of armour layer and non-uniform bedform after dam failure. A dam failure pattern is proposed by considering the variation of the erosion surface slope caused by the change in erosion rate and the occurrence of deposition during dam failure. This study improves the understanding of landslide dam failure and induced morphological changes, and further aids the hazard management.
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Yang, J., Shi, Z., Soares Frazao, S., Zheng, H., & Shen, D. (2024). Influence of dam and erodible bed material composition on landslide dam failure and induced morphological changes: an experimental study. Bulletin of Engineering Geology and the Environment, 83(2), 21. https://doi.org/10.1007/s10064-024-03556-6 (Original work published 2024)