Comparison of Flow Resistance Laws for Debris Flow by 1d Numerical Model (PAP014847)
Kaiheng Hu, Pu Li, Jinheng Zhao
Flood forecasting and early warning systems
Four frequently-used debris-flow resistance relationships (Bingham, Bagnold, Voellmy, and Turbulent) are examined by 1D depth-averaged Saint-Venant equations which are numerically solved with non-oscillatory central scheme for one-dimensional hyperbolic conservation laws. The scheme combined with Front-tracking method is suitable for capturing debris-flow surges that are often observed in nature. Comparison of the numerical simulation results with field data from eyewitness and measured by ultrasonic sensor at Jiangjia Ravine demonstrated that debris-flow surges display two kinds of flow-depth profiles in Lagrange and Euler reference frames. Furthermore, among the four resistance relationships, it is found that the turbulent resistance law has the best agreement with the event for the front velocities and stopping location. The Bingham law exhibits a sharper front profile than the other resistance laws although it gives a reasonable result for the runout distance. The Bagnold and Voellmy laws have a great deviation from the event for the runout distance and front velocities.