In mountainous regions, high-locality landslides have the characteristics of a latent disaster process with a wide disaster range, which can easily cause large casualties. Therefore, early landslide identification and dynamic stability evaluation are significant. We first used multi-temporal synthetic aperture radar data to detect potential landslides at Yezhi Site Area during the 2015–2020 period, identifying and mapping a total of 18 active landslides. The study area was found to have an average deformation rate between −15 and 10 mm/y during the period. Then, time series and spatiotemporal deformation characteristics of landslides were examined using interferogram stacking and small baseline interferometry techniques. The results show that the majority of the landslide deformations detected exhibit a periodic variation trend, and the study area was in a slow deformation state before 2017. Finally, combined with detection results, Google Earth optical images, and field investigations, it is concluded that the main factors affecting the time series deformation and spatial distribution of landslides in the study area are rainfall, geological factors, and engineering activities. The results of this study provide valuable technical references and support for early identification and dynamic stability evaluation of regional active landslides in complex terrain, especially for high-locality landslides.

High-position landslide debris flows triggered by earthquakes frequently occur in the southwest mountainous areas of China. The research on the high-speed and long-distance movement characteristics and mechanisms of such landslide debris flows is crucial for disaster early warning and prevention. This study focuses on the high-position rockfall-landslide debris flow in Luding County, Sichuan Province, and uses a combination of field investigation, rheological testing, and numerical simulation to reveal the rheological properties and catastrophic mechanisms of landslide debris flows under seismic loading. The results show that with increasing water content, the storage modulus (G′) and loss modulus (G′′) of the debris-flow soil significantly decrease, and shear-thinning is more pronounced at low water contents. High-frequency vibration (>10 Hz) suppresses the solid–liquid transformation of the soil, while low-frequency vibration (<1 Hz) accelerates its liquefaction. As frequency increases, the dependence of yield shear strain on water content decreases significantly. Also, as water content decreases, the dependence of yield shear strain on frequency lessens. Numerical simulation using RAMMS (Rapid mass movement simulation) shows a high overlap rate of 92.3% between the simulated debris-flow movement and the actual disaster-affected area, confirming the model′s reliability. The study indicates that seismic loading reduces the shear strength of the soil, increases pore-water pressure, and causes particle rearrangement, thus lowering the critical conditions for debris-flow initiation. The findings provide a theoretical basis for early warning and prevention of high-position landslide debris flows triggered by earthquakes.

Loess mudflows are typical geological hazards that undergo a dynamic solid-to-liquid transition, yet the yielding process remains poorly constrained. This study investigates the nonlinear rheological behavior of loess slurries with water contents of 28%, 32%, and 36% using large amplitude oscillatory shear (LAOS) and Fourier-transform rheology at frequencies from 0.1 to 10 Hz. Results show that the rheological response evolves from linear behavior to solid-like nonlinearity with a G″ overshoot, and finally to fluid-like behavior. Increasing frequency lowers the linear limit and nonlinear transition strain but raises the nonlinear limit and solid–liquid transition strain. Higher water content can increase the strain required for complete liquefaction; at 36% water content and 5-10 Hz, G′ remains above G″ and no solid–liquid transition occurs. The nonlinear coefficient Q remains nearly constant at small strains and decays with increasing strain and sensitive to strain, water content, and frequency, serving as an early indicator of structural change. SEM observations reveal that higher water content disperses the soil structure and weakens interparticle interactions, explaining the weaker nonlinearity and delayed fluidization. These findings provide a strain-resolved characterization of the solid–liquid transition in loess mudflows and offer theoretical support for hazard assessment and early warning.