SETTLING OF FINE SEDIMENT IN A CHANNEL WITH EMERGENT VEGETATION

The potential for enhanced removal of sediment from flowing water in a channel by means of settling on vegetation was studied theoretically and experimentally. Settling on vegetation was modeled as a distributed sink of sediment with vegetation spread throughout depth and length of the channel. Sediment-capture experiments were performed in a laboratory channel using model vegetation and well-sorted silt. The theory predicts that settling on vegetation has the potential to increase sediment-capture efficiency considerably, and this was demonstrated in the experiments. The enhancement of sediment removal was greater for artificial vines than for inclined strips. For the runs with flow velocities greater than 10 mm/s the sedimentation efficiency was less than predicted. The reduced efficiency could be related to bed destabilization (which was observed in some runs), re-entrainment from the vegetation, or sediment sliding off the vegetation.

Language

  • English

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Filing Info

  • Accession Number: 00797203
  • Record Type: Publication
  • Contract Numbers: 59890200, BD-2775/93, 604/11/13093
  • Files: TRIS
  • Created Date: Aug 7 2000 12:00AM