To reveal the impact of slope angle change on toppling deformation, this paper takes the dam toppling deformation of Gushui Hydropower Station based at Lancang River as an example, based on which three groups of models with different slope angles are conceptualized and designed. Through the centrifuge test, the evolution of toppling deformation of a counter-tilt layered slope under different slope angles was simulated. The research results show that: (1) The steeper the slope angle, the shorter the cumulative time required for such deformation is, the larger the toppling deformation will be, and it is more likely that multi-stage fracture zones will occur during the toppling process. (2) The toppling deformation process can be summarized as four stages. (3) The toppling deformation mainly occurs above the datum surface of the toppling fracture; the angle between the datum surface and the normal of the layer is between 12° to 16°. This value shall not change as the slope angle changes. (4) The lesser the slope angle is, the more likely the toppling deformed slope will be experience overall slipping instability. while the steeper the slope angle is, the greater the possibility of collapse after the rock mass falls.

Reservoir impoundment imposes a significant triggering effect on bank landslides. Studying the early identification of landslides and their stability concerning reservoir water levels and rainfall is vital for guaranteeing the safety of residents and infrastructure in reservoir regions. This study proposed a method for establishing a dynamic inventory of active landslides at large hydropower stations using integrated remote sensing techniques, demonstrated at Lianghekou Reservoir. We employed interferometric stacking synthetic aperture radar (stacking-InSAR) technology, small baseline subset interferometric synthetic aperture radar (SBAS-InSAR) technology, and optical satellite images to identify and catalogue active landslides. Moreover, we conducted field investigations to examine the deformation characteristics of landslides. Finally, Pearson’s correlation analysis was employed to evaluate the response between deformation values, reservoir water levels, and rainfall. The results revealed 75 active landslides, including 12 long-term active landslides before impoundment and 63 new landslides after impoundment, which were primarily concentrated in the Waduo and Yazho–Zatou regions. The correlation coefficient between landslide deformation values and the reservoir level was high (0.93), while the correlation coefficient with rainfall was low (0.57). The results of this research offer a crucial foundation for preventing and mitigating landslides in reservoir areas.