IAHR, founded in 1935, is a worldwide independent member-based organisation of engineers and water specialists working in fields related to the hydro-environmental sciences and their practical application. Activities range from river and maritime hydraulics to water resources development and eco-hydraulics, through to ice engineering, hydroinformatics, and hydraulic machinery.
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You are here : eLibrary : IAHR World Congress Proceedings : 36th Congress - The Hague (2015) ALL CONTENT : Sediment management and morphodynamics : Flow structure and bed evolution after weir removal
Flow structure and bed evolution after weir removal
Author : SUMIDA HIDEYUKI(1), MUTO YASUNORI(2) & TAMURA TAKAO(3)
ABSTRACT
River crossing structures have contributed to flood control and irrigation. However, they adversely affect the riverí»s biota
and sediment transport. Recently methodology of full or partial removal of a weir in order to eliminate discontinuity of the
river is under consideration. Nevertheless, impact on bed morphology and channel development due to the removal has
not been fully explored.
In this paper flume experiments were conducted to study effects of partial removal of a weir on bed morphology in its
upstream. Detailed velocity measurements were conducted in order to clarify a mechanism of bed evolution process
after the weir removal. The depth and width of the removed part were systematically changed.
It is found that a channel formed from the removed part toward the upstream induces flow concentration and strongly
affects cellular secondary flow structure after the removal. Velocity distributions in several cross-sections clearly shows
that cellular secondary flow structure has close relation with sandbar formation. In addition shape of the channel near
the weir, which is changed after the removal, is different in accordance with the removal shape. The shape is deemed to
affect strongly the flow concentration, and eventually sandbar formation in a whole flume.
File Size : 1,272,285 bytes
File Type : Adobe Acrobat Document
Chapter : IAHR World Congress Proceedings
Category : 36th Congress - The Hague (2015) ALL CONTENT
Article : Sediment management and morphodynamics
Date Published : 13/08/2015
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