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ARS Home » Southeast Area » Oxford, Mississippi » National Sedimentation Laboratory » Watershed Physical Processes Research » Research » Publications at this Location » Publication #112494

Title: EFFECT OF RIPARIAN VEGETATION DENSITY ON STREAM FLOW VELOCITY

Author
item PIRIM, TANER
item Bennett, Sean
item BARKDOLL, BRIAN

Submitted to: American Society of Civil Engineers Water Resources Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 6/1/2000
Publication Date: N/A
Citation: N/A

Interpretive Summary: Stream restoration techniques generally focus on protecting or restoring aquatic, riparian, and floodplain habitat and habitat resources. This study focused on developing a methodology to systematically vegetate a straight, eroded stream corridor in order to improve habitat and habitat resources for fish and wildlife, and provide the processes necessary to cause stream meanders to form. A laboratory experiment was performed in a flume with simulated vegetation. The density of the vegetation zones was altered while all other flow characteristics were kept constant. A video technique was used to determine surface flow characteristics. Measurements revealed that as vegetation density increased, the tendency for the stream to meander also increased. This study established a methodology to induce sinuosity in straight, eroded channels using simulated vegetation. Such knowledge is important for action agencies involved in the rehabilitation of degraded streams and rivers.

Technical Abstract: River restoration is the most important recent advance in river engineering. Stream restoration techniques generally focus on protecting or restoring aquatic, riparian, and floodplain habitat and habitat resources. This study focused on developing a methodology to systematically vegetate a straight, degraded stream corridor in order to improve habitat and habitat resources for fish and wildlife, and provide the stimuli necessary to cause stream meanders to form and equilibrate. Hence a laboratory experiment was performed in a flume with simulated alternating vegetation zones. The density of the vegetation zones was altered while all other flow characteristics were kept constant. Particle Image Velocimetry (PIV) was used to determine surface flow characteristics. PIV measurements revealed that as vegetation density increases, the following flow parameters related to river meandering increase: average thalweg velocity, flow circulation downstream of the vegetation zone, sinuosity, reattachment length, depth, and resistance. This study established a methodology to induce sinuosity in straight, degraded channels using vegetation and determined that placing roughness elements that simulate natural vegetation can significantly alter the flow direction.