Insights into small landslides inducing major disasters in the Wumeng Mountain area from the Liangshui landslide

The Wumeng Mountain area in China is highly susceptible to landslides due to tectonic movements, heavy monsoon rains, and human activities. Despite their small size, these landslides can cause significant damage. The 2024 Liangshui landslide, with a volume of about 70,000 m³, resulted in 44 fatalities and marked the third major winter geological disaster in the Zhenxiong range in recent years. Comprehensive research on this landslide is crucial for understanding its triggers and failure mechanisms. Using the Rapid Mass Movement Simulation dynamic model and remote sensing data, we analyzed the dynamic evolution of the Liangshui landslide, following a thorough survey of its characteristics and potential failure mechanisms. Our findings indicate that landslide-prone strata, fractured rock, and steep source areas provided the necessary material and mechanical foundation. Seepage of fracture water after a prolonged precipitation softened the rock mass and decreased slope stability. A sudden drop in temperature and snowfall caused frost heave, leading to the expansion of rock fractures and ultimately triggering the landslide. This research provides insight into how small landslides can induce major disasters in the Wumeng Mountain area, as well as those triggered by prolonged rainy (or snowy) conditions in Zhenxiong County.