A predictive model for the geometry of landslide dams in V-shaped valleys
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ORIGINAL PAPER
A predictive model for the geometry of landslide dams in V-shaped valleys Dongyang Li 1 & Tingkai Nian 1
&
Hao Wu 1 & Fawu Wang 2 & Lu Zheng 3
Received: 3 September 2019 / Accepted: 27 April 2020 # Springer-Verlag GmbH Germany, part of Springer Nature 2020
Abstract Landslide dams are formed mostly in V-shaped valleys, with poor stability and a high risk of failure. Once landslide dams fail, they may cause floods or debris flows that endanger lives, property, and infrastructure downstream. Therefore, it is important to evaluate the stability immediately once a landslide dam is formed. The geometry of a landslide dam is the most critical to its stability assessment. However, the complex terrain and geomorphological conditions in the disaster area often make field surveys difficult. Aerial photography and satellite imagery technology are usually limited by poor weather conditions, which bring severe restrictions to the timely acquisition of the geometry of a landslide dam. In this paper, a discrete element simulation model was proposed and verified by two experiments, and then a series of numerical simulations were performed to investigate the geometry and formation process of landslide dams under different topographic factors including the motion path dip-angle, the river bed inclination, and the angle between valley slopes (valley angle). The results show that the geometry and formation process of landslide dams are significantly affected by the topographic factors. According to the results of comprehensive numerical analysis, a simple predictive model for landslide dam geometry in V-shaped valleys was established, and two landslide dams with data collected from early events were employed to validate the predictive model. Based on the easily accessible topographical factors, the proposed model accomplished the fast prediction of landslide dam geometry. This research provides a vital basis for the stability evaluation of landslide dams and can be used for the disaster emergency response before the dams break. Keywords Landslide dam . Geometry . Formation process . Discrete element method . Predictive model
Introduction * Tingkai Nian [email protected] Dongyang Li [email protected] Hao Wu [email protected] Fawu Wang [email protected] Lu Zheng [email protected] 1
School of Civil Engineering and State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology, Dalian 116024, Liaoning, China
2
Department of Geoscience, Shimane University, Matsue 690-8504, Japan
3
College of Civil Engineering, Fuzhou University, Fuzhou 350108, China
Landslide dams are formed by landslides that obstruct river channels or valleys (Korup and Tweed 2007; Xu et al. 2009). Statistics show that more than 90% of such disasters occur in mountainous areas with deep narrow valleys because the landslide mass rushing into the V-shaped valley can reach the other side of the river easily resulting in a complete blockage of the river channel (Yan 2006; Yuan 2012). As soon as
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