This study focuses on composite hazards of high-position rock avalanche-induced impulse waves, considering the sliding surface inclination angle θ₁ at the source area and the slope angle θ₂ along its movement path. A two-dimensional generalized physical model was developed to simulate rock avalanche‑impulse wave interactions, with θ₁ and θ₂ as key geometric variables. The granular flow movement and impulse wave characteristics under different combinations of θ₁ and θ₂ were analyzed. Additionally, grey system analysis was applied to evaluate the sensitivity of the initial wave peak to θ₁ and θ₂. Experimental results show that: (1) Under the same θ₂ condition, a larger θ₁ results in a shorter total movement duration Tₜₒₜ of debris particles. When θ₁ exceeds the repose angle φ_r of the test particles by about 10°, further increasing θ₁ does not cause a reduction rate of Tₜₒₜ greater than 20%. (2) Under the same θ₁ condition, when θ₂ is greater than the internal
friction angle of the test particles by 10°~20°, or when θ₂ is only less than 10° larger than φ_r, the formation area of the impulse wave expands, causing the sharp attenuation area to shift backward. (3) The grey correlation degrees for the sensitivity of  θ₁ and θ₂ to the initial wave peak are [θ₁ θ₂]^T=[0.942 0.406]^T,
indicating that the sliding surface inclination angle profoundly dominates over the slope angle in the initial wave peak formation.
 

High-position rock avalanches; Sliding angle; Physical experiment; Impulse wave; Grey correlation degree