Settling of fine sediment in a channel with emergent vegetation

Authors
Citation
Ah. Elliott, Settling of fine sediment in a channel with emergent vegetation, J HYDR ENG, 126(8), 2000, pp. 570-577
Citations number
19
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Civil Engineering
Journal title
JOURNAL OF HYDRAULIC ENGINEERING-ASCE
ISSN journal
0733-9429 → ACNP
Volume
126
Issue
8
Year of publication
2000
Pages
570 - 577
Database
ISI
SICI code
0733-9429(200008)126:8<570:SOFSIA>2.0.ZU;2-N
Abstract
The potential for enhanced removal of sediment from flowing water in a chan nel by means of settling on vegetation was studied theoretically and experi mentally. Settling on vegetation was modeled as a distributed sink of sedim ent with vegetation spread throughout depth and length of the channel. Sedi ment-capture experiments were performed in a laboratory channel using model vegetation and well-sorted silt. The theory predicts that settling on vege tation has the potential to increase sediment-capture efficiency considerab ly, and this was demonstrated in the experiments. The enhancement of sedime nt removal was greater for artificial vines than for inclined strips. For t he runs with flow velocities >10 mm/s the sedimentation efficiency was less than predicted. The reduced efficiency could be related to bed destabiliza tion (which was observed in some runs), re-entrainment from the vegetation, or sediment sliding off the vegetation.