Effects of Inflow Rate and Channel Bed Slope on Noncohesive Landslide Dams during Overtopping Failure Based on Flume Tests

The sudden failure of landslide dams poses significant threats to human lives and downstream infrastructure. The dam breach mechanisms and associated breach parameters are strongly influenced by hydrological conditions. In this study, a series of flume experiments were conducted to investigate the effects of inflow rate and channel bed slope on breach evolution, outflow discharge, and residual dam parameters. The results indicate that dams fail through headcutting and backwards erosion under various inflow rates and channel bed slopes. Both peak discharge and scale amplification increase linearly with increasing inflow rate. Breach duration exhibits a linear increase during Stages I, II, and III, while showing no clear relationship in Stage IV. With increasing channel bed slope, peak discharge and scale amplification initially rise before subsequently declining. The durations of Stages I and II decrease, whereas the durations of Stages III and IV first decrease and then increase as channel bed slope increases. Residual dam height decreases with increasing inflow rate, while it initially decreases and then fluctuates with increasing channel bed slope. ... mehrFurthermore, the location of breach initiation gradually shifts from the downstream toe towards the dam crest with increasing inflow rate and channel bed slope. This study enhances the understanding of landslide dam failure mechanisms and provides valuable insights for hazard assessment under varying hydrological conditions.