Landslides are a significant geological hazard with substantial socio-economic and environmental consequences, particularly in northwestern Sichuan, SW China, where complex geological and climatic conditions contribute to their occurrence. This study examines 1629 recorded landslide events, including 240 active landslides that have undergone substantial changes over the past two decades. By analyzing multi-temporal satellite imagery, this research investigates the relationship between landslide occurrence and key environmental factors such as annual rainfall and the Normalized Difference Vegetation Index (NDVI). The results reveal that landslides are most frequent on southwest-, south-, east-, and southeast-facing slopes, where the Föhn effect interacts with rainfall and vegetation patterns, thereby increasing landslide susceptibility. Rainfall intensity is identified as a critical factor, with landslide areas expanding significantly when annual rainfall exceeds 650 mm, while minimal changes are observed when rainfall is below 550 mm. The relationship between the NDVI and landslide occurrence is non-linear; higher vegetation cover does not necessarily correlate with reduced landslide frequency. Notably, landslide expansion is more pronounced when NDVI values are below 0.82, with a suppression effect occurring beyond this threshold. A threshold model based on the interaction between the NDVI and rainfall provides valuable insights into landslide dynamics, offering a framework for improved risk management. Slope characteristics are crucial in landslide evolution, with steeper slopes leading to greater vertical drops and more frequent events, making slope zone identification key for predicting future expansion.

Clarifying the dynamic evolution patterns of landslides is crucial for landslide disaster prevention. Focusing on the northwestern region of Sichuan, analyzing 240 typical cases of actively deforming landslides over the past twenty years, examining the impact of various environmental factors such as vegetation, and rainfall on the dynamic development of landslides. Research indicates that vegetation coverage is a crucial factor influencing the development of landslides. Areas with high vegetation coverage tend to contribute more significantly to landslide activity. This phenomenon may be attributed to the excessive weight of root systems and increased rainfall interception, which negatively impact slope stability. In contrast, regions with high rainfall experience a more considerable increase in both the area and frequency of landslides. However, the annual average rainfall over a 20-year period shows minimal correlation with the frequency of landslide activity. This suggests that short-term intense rainfall events may play a more critical role in triggering landslide occurrences. By integrating the dynamic evolution patterns of landslides, targeted disaster prevention measures formulated can effectively enhance the region’s proactive disaster prevention capabilities.