Author(s): Robert R. Wells; Sean J. Bennett; Carlos V. Alonso
Linked Author(s): Carlos V. Alonso
Keywords: No Keywords
Abstract: Headcut erosion can severely accelerate soil loss in upland concentrated flows and lead to significant soil degradation in agricultural areas. Previous experimental work has demonstrated that actively migrating headcuts display systematic morphodynamic behavior, and impinging jet theory can provide an excellent theoretical foundation for this erosional phenomenon. This research sought to examine systematically the effect of an upstream sediment inflow on the morphodynamics of actively migrating headcuts in upland concentrated flows. Using a specially-designed experimental facility, actively migrating headcuts were allowed to develop, and then they were subjected to an upstream sediment load composed of sand. As the upstream sediment feed rate increased, the size and migration rate of the headcut decreases markedly, but sediment discharge is less affected. The headcut erosion process is arrested as sediment inflow rate increases above a threshold value. This research suggests that headcut erosion can be greatly modulated by an upstream sediment source, further complicating the prediction of soil erosion on upland areas.
Year: 2009