Kinematic slope stability assessment using UAV-based photogrammetry at Gunung Geulis Cinanjung Tanjungsari, Sumedang Regency, Indonesia

A rapid and accurate slope stability assessment method is crucial for reducing human and economic losses associated with slope failures. This study evaluates the kinematic stability of the Gunung Geulis slope and determines the dominant structurally controlled failure mechanisms. A UAV-based photogrammetric and kinematic approach was applied to assess slope instability. More than 170 high-resolution images were processed in ShapeMetriX to generate a 3D surface model from which discontinuity orientations, spacing, and persistence were extracted. These structural attributes were grouped into representative Joint Sets and investigated the likelihood of Planar Sliding (PS), Wedge Sliding (WS), and Flexural Toppling (FT). The results indicate that, under a slope dip of 70°, dip direction of 359°, and friction angle of 25°, WS is the dominant kinematically feasible failure mode, affecting 26.35% of joint intersections. Furthermore, the likelihood of PS and WS increases markedly with slope dip angle, whereas FT exhibits minor variation.