Numerical Simulation of Landslide Dam Deformation by Overtopping Flow

• Published in: International Journal of Erosion Control Engineering Vol. 7; no. 3; pp. 85 - 91
• Main Authors: AKAZAWA, Fumiaki, IKEDA, Akikazu, HAYAMI, Satoshi, HARADA, Norio, SATOFUKA, Yoshifumi, MIYATA, Shusuke, TSUTSUMI, Daizo
• Format: Journal Article
• Language: English
• Published: Japan Society of Erosion Control Engineering 2014
• Subjects: field experiment; inertial debris flow; landslide dam; numerical simulation; overtopping
• ISSN: 1882-6547; 1882-6547
• DOI: 10.13101/ijece.7.85

Recently, climate change has resulted in an increasing number of heavy rainfall events. Heavy rainfalls tend to cause large-scale landslides and create large landslide dams. Large landslide dams retain a large amount of water and often burst causing floods and catastrophic damage in the downstream area. Therefore, the study of landslide dam deformation is essential for predicting potential floods to implement effective flood risk management. To understand the landslide dam deformation process and dam outflow discharge characteristics, we carried out field experiments of landslide dam erosion by overtopping flow. In the field experiments, we observed the landslide dam deformation process directly. In a third experimental case, small slope failure occurred and we found that small slope failure affects the outflow discharge. In addition, we developed a numerical model to simulate landslide dam erosion by overtopping flow. To improve the prediction of the outflow discharge, we incorporated the inertial debris flow model, the side bank erosion model, and the slope collapse model into our numerical model. The resulting proposed model is tested by comparing the results of simulation with observation. The numerical model is capable of predicting outflow discharge by landslide dam burst.