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Effect of initial step height on headcut development in upland concentrated flows
Author(s) -
Bennett Sean J.,
Casalí Javier
Publication year - 2001
Publication title -
water resources research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.863
H-Index - 217
eISSN - 1944-7973
pISSN - 0043-1397
DOI - 10.1029/2000wr900373
Subject(s) - surface runoff , hydrology (agriculture) , erosion , sediment , geology , sorting , sediment transport , geotechnical engineering , geomorphology , ecology , computer science , biology , programming language
Experiments were conducted to examine the effect of initial step height on growth, development, and upstream migration of headcuts in concentrated flows typical of rills, crop furrows, and ephemeral gullies. In a laboratory channel, packed soil beds were constructed with preformed headcuts ranging in height from 5 to 50 mm. Each bed was subjected to the same simulated rain, which produced a protective surface seal, followed by an overland flow, which caused soil erosion exclusively at the headcut. After a brief period of bed adjustment, migration rate, scour hole geometry, and sediment yield reached asymptotic values, but the time and length required to reach these asymptotes decreased as the initial step height increased. Steady state headcut dimensions, sediment yield, and the slope of the sediment deposit increased as initial step height increased, but sediment sorting patterns downstream of the migrating headcut remained unchanged.