The upper Yellow River canyon on the northeastern margin of the Qinghai-Tibet Plateau has experienced numerous giant paleolandslide-dammed lake-outburst flood disaster chains. Understanding their formation and evolution is essential for hazard assessment and risk mitigation (Guo et al., 2015). Taking the Dehenglong giant paleolandslide as a representative case, this study develops a depth-averaged landslide-damming model coupled with an outburst flood model incorporating sediment transport and erosion–deposition processes. Simulations reproduce the complete evolution of the disaster chain, including landslide motion, river blockage, lake formation, and dam breaching. The results show that the Dehenglong landslide had a volume of 3.50 billion m³, reached a peak average velocity of 44.5 m/s, and completed its movement within 120 s. The landslide formed a 234-m-high dam, impounding a giant lake with an area of 280 km² and a storage capacity of 23.23 billion m³. The dam breach lasted approximately 100 h and generated a peak discharge of 238 300 m³/s. The resulting flood propagated about 900 km downstream along the Yellow River and reached a maximum water depth of 158 m. Although the landslide itself traveled only a limited distance, the resulting disaster chain extended over approximately 1 000 km of the river channel, demonstrating a remarkable disaster amplification effect. These findings improve the understanding of giant landslide-dammed lake-outburst flood disaster chains and provide scientific support for hazard assessment and disaster prevention in the Yellow River Basin.

depth-averaged models,giant landslides,disaster chain,full-process simulation