Abstract: ObjectiveTaking the "9·03" mining slag debris flow event in Jinyue Ravine, Xining , in 2024 as an example, the effect and cascading mechanisms of historically accumulated mining slag on channel erosion was elucidated in eastern Qilian Mountains under changing climatic conditions.Methods Through field investigations and laboratory experiments, the Iverson debris-flow initiation model, hydrodynamic analysis, and the FLO-2D model were employed to conduct a comparative analysis of disaster processes in the Jinyue Ravine under two scenarios (i.e., with and without mine waste deposits). By integrating multiple typical mining area cases in the eastern Qilian Mountains, the amplification mechanism of cascading hazards induced by mine waste accumulation in the region was revealed.Results Under the conditions of loose structure of the abandoned silica ore heap the low shear strengthand the extreme rainfall conditions, thee silica ore heap became instable and landslide occurred. The landslide body that poured into the channel led to the extrusion of the flood channel and provided a large amount of loose material source for the debris flow, leading to increased flow bulk density by about 20 %. The dilute flow changed from in the natural state to the sub-viscous flow with stronger destructive power. The change of topography and provenance led to the increase of debris flow intensity. The flow velocity was 43 % higher than that in the natural state, and the flood peak flow was increased by 58.84 %. The flood range of debris flow was expanded under extreme rainfall events and the high-risk area was dominant.Conclusions The mine residues became instable and the disasters were developed and amplified under extreme rainfall event in the eastern Qilian Mountains, providing a typical example of disaster chain processes in areas disturbed by anthropogenic mining activities. It is recommended that mitigation strategies for mine residues be optimized based on the disaster amplification process of residue-induced ravine erosion, and that debris flow risk prevention and control engineering be strengthened. These findings provide a theoretical foundation for disaster prevention and control as well as ecological security barrier construction in the eastern Qilian Mountains and other regions with similar geological and climatic backgrounds. Keywords : slag heap material；ravine erosion；disaster amplification；FLO-2D simulation；eastern section of Qilian Mountains