|STEIN, OTTO - MONTANA STATE UNIVERSITY
Submitted to: Water Resources Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/19/2002
Publication Date: 12/19/2002
Citation: ALONSO,C.V., BENNETT,S.J., STEIN,O.R. PREDICTING HEAD CUT EROSION AND MIGRATION IN CONCENTRATED FLOWS TYPICAL OF UPLAND AREAS. WATER RESOURCES RESEARCH. 2002. v. 38. p. 1303.
Interpretive Summary: The formation and upstream migration of headcuts in rills, row-crop furrows, and ephemeral gullies is an important factor in soil losses and sediment yield from agricultural lands. Improvements in soil erosion predictions are predicated upon better characterizations of these processes. Recent experimental research has added new insights on erosion due to migrating headcuts. It was observed that once steady state is reached, headcut migration rate, scour-hole geometry, and sediment yield remain constant. Within individual experiments, the morphology of the headcut did not vary significantly during its migration once steady-state conditions were achieved; a behavior that is interpreted as the headcut exhibiting self-similarity properties. The present analysis takes advantage of the observed self-similarity properties to develop a mathematical model of headcut erosion and migration. Computed results yield acceptable comparisons with measured values. This work is relevant to ARS, other federal and state agencies, and to the US farming community because it allows us to make improved predictions of how much soil erosion will occur on agricultural lands.
Technical Abstract: Soil erosion due to headcut development and migration can devastate agricultural lands yet current prediction technology does not address this erosion process. Here an analytical model of this important erosional phenomenon is presented. Realistic, physically-based approximations to the laws governing mass, momentum, and energy transfer in the neighborhood of the scour hole result in closed-form predictive algorithms for plunge pool erosion and headcut migration. The model introduces a special treatment of nonventilated overfall conditions, is limited to homogeneous, unbounded soil layers, and is validated by available experimental measurements.