Headcut is a vertical or near-vertical drop in the channel bed. The migration of headcut induces channel bed and bank instabilities, worsens erosion, and increases the sediment load delivered to downstream reaches. The headcut migration process was simulated at NCCHE using three-dimensional models. The fluvial erosion due to the jet impingement below the headcut was calculated, considering the effects of pressure fluctuation, pressure gradient, bed slope, downward flow, and turbulence intensity. The mass failure was determined by a time-averaged model that treats the discontinuous event as a continuous mass wasting process. The simulated headcut migration speed, and scour hole profile below the headcut are in good agreement with experimental measurements.
Headcut Migration in Natural Streams (after USDA-ARS NSL)
Simulated Headcut Migration Process in Bennett et al’s (1997) Experiment
Measured and Calculated Breakpoint Migration Distances with Timein Bennett et al’s (1997) Experiment
