Sediment transport effects on river bed morphology in vegetated channels

In order to investigate the streambed instability due to randomly distributed vegetation, different experiments were conducted in a laboratory flume. These experiments involved varying flow conditions, diameter, height, and density of vegetation. The photogrammetry technique and a Laser Scanner were utilized to capture the morphology of the sediment bed and detect any changes that occur owing to the presence of vegetation and flow conditions. The results of the experimental campaign suggest that the presence of vegetation promotes streambed stability and helps in forming multiple bars. When vegetation density is low, sediment bedload flows primarily in the longitudinal direction. As vegetation elements increase, bed structures become shorter but follow similar trends. Submerged vegetation formation leads to an increased number of isolated structures in bed morphology as compared to emergent vegetation. In addition, runs with low flow discharge show the lateral dispersion of sediments.