Movement of cobbles in a gravel-bed stream during a flood season

摘要

In a gravel-bed perennial stream in western Wyoming, 159 cobbles were tagged and placed on the stream bed. Thirty-five percent were recovered after one flood season during which the peak flow was 34 m3/s. Sixty-one percent of those recovered had been buried. The b axis of the tagged rocks ranged from 34 mm to 116 mm. The distance transported ranged from 0 to 420 m; 95% of the recovered cobbles had moved. There is no clear relationship between particle size and distance transported; distance of transport seems to be more closely related to position (stream edge or center) at time of entrainment. Susceptibility to burial seems to be related to both particle size and position at time of entrainment.