Analysis of rainfall response and graded warning for landslides

Rainfall-induced landslides are characterized by stochasticity and complexity, making the development of effective early warning models crucial for disaster prevention and mitigation. Focusing on creeping landslides in Zigui County within the Three Gorges Reservoir area, this study proposes a rainfall early warning method based on a displacement ratio model. By analyzing the response relationship between landslide displacement and cumulative rainfall, a time-phased exponential early warning model was established, along with four-level warning thresholds (78.3 mm, 160.1 mm, and 196.6 mm). The model, which uses cumulative rainfall as the core input variable, explains approximately 30-40% of the variation in landslide displacement. Validation using three landslide events in 2021 and historical extreme rainfall events shows that the model successfully issued warnings for all incidents (100% recall), albeit with an 8% false alarm rate. The proposed method features concise parameters and strong operability, offering a technical reference for landslide early warning in similar regions, though its applicability should be further validated in conjunction with specific geological conditions.