Submitted to: Water Resources Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/4/2001
Publication Date: N/A
Interpretive Summary: Stream restoration techniques generally focus on protecting or restoring aquatic, riparian, and floodplain habitat and habitat resources. While many studies have discussed the effects of riparian vegetation on flow within rivers and streams, none has utilized vegetation for the purpose of inducing a straight stream to meander. 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 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 programs often use vegetation to enhance the biological functionality, recreational opportunities, and aesthetic beauty of degraded stream corridors. Yet none has used vegetation for the purpose of inducing a straight channel to meander. A flume-based experimental study was designed to alter the flow pattern within a straight, degraded stream corridor by using simulated emergent vegetation of varying density placed at key locations within the channel. Placement of vegetation zones was determined using an empirical relation for equilibrium meander wavelength based on the imposed flow rate and surface flow velocities were quantified using particle image velocimetry. It was shown that (1) flow velocity can be markedly reduced within and near the vegetation zones, (2) flow can be diverted towards the opposite bank, and (3) vegetation density can control the magnitude of these effects.