2:45 PM - 3:00 PM
[HCG35-15] A numerical model for predicting alluvial cover in clast-rough and clast-smooth bedrock channel
Keywords:Bedrock river, Fluvial geomorphology, Modeling, Sediment transport
The numerical results show that: 1) the cover fraction is smaller when the bedrock relative roughness is smaller; 2) when bedrock roughness is larger than alluvial roughness (clast-rough bedrock), the cover fraction gradually increases with sediment supply; 3) in the case of clast-rough bedrock with high sediment supply, mixed alluvial-bedrock alternate bars form, and a meandering thread of alluvial material migrates downstream; 4) when bedrock roughness is smaller than alluvial roughness (clast-smooth bedrock), a fully exposed bedrock channel requires a relatively large sediment supply before any alluvial patch is formed, and as supply increases, rapidly transitions to a fully alluvial channel; 5) in the case of clast-smooth bedrock, the transition between a fully exposed bedrock channel and a fully alluvial channel has hysteresis.