Analysis of movement and accumulation characteristics and dynamic process of the high-elevation landslide in Liangshui village, Wumeng mountain area

Small-scale landslides initiated at high elevations in the Wumeng mountain area often lead to servere geological hazards due to rapid conversion of gravitational potential energy into kinetic energy. This study investigate the deformation, movement, and accumulation characteristics of the Liangshui Village in Zhaotong, Yunnan Province, triggered on January 22, 2024, through field surveys, UAV-based aerial surveys, and high-precision image-based particle recognition techniques. Numerical simulations were conducted to reveal the post-failure dynamic behavior of the landslide. Results show that the landslide motion lasted approximately 50 seconds and evolved through four distinct phases: (i) initial acceleration following shear failure, (ii) rapid acceleration during disintegration and sliding, (iii) gradual deceleration caused by collisions and fragmentation, and (iv) final deposition and stablization. The sliding mass primarily exhibited a transition from dense to dilute flow regimes, reaching a peak velocity of 37.5 m/s, and traveling a maximum distance of 465 meters. It ultimately formed a fan-shaped deposit with a volume of 14.0 × 10⁴ m³, characterized by higher elevation in the southeast and lower in the northwest, with a maximum thickness of 12 meters. The particle size distribution within the accumulation zone exhibits distinct zoning characteristics. Microtopographic features along the landslide significantly influenced both the runout distance and the spatial distribution of deposit thickness.Simulation results are consistent with the field survey results. These results provide valuable insights for understanding the disaster characteristics of similar high-elivation landslide events and for improving risk prediction and assessment.