Experiment on fundamental behaviours of wavelength and height of vegetated alternate bar in river

Abstract

he study on the alternate bar has been implemented by many researchers previously. However, the detailed analysis of the formation of the vegetated alternate bar is still not sufficient, especially on the bar wavelength, height, and width. Therefore, this present study provides an analysis of the experimental approach on the vegetated alternate bar formations. The focus was on the characteristics of wavelength, height, and width of the alternate bar. The objective of the study is to investigate the relationship of these parameters for three different conditions of alternate bar formations of non-vegetated, full and half patches of vegetation alternate bar. The flume of 10 m long and 1 m wide with erodible bed and fixed banks were used for the experiments with uniform bed sediment of size 0.8 mm. The wavelength and height of both full and half vegetated alternate bars increased compared to non-vegetated thus stabilized the formation of the alternate bar in the channels. The vegetation also reduced the value of the shield parameter to produce high deposition on the bar. The width of the bar increased at the head and body of the vegetated bar however it was decreased in the area of bar edge. Therefore, it could say that vegetation gives positive impacts on the alternate bar formation characteristics especially on its formation and stability in the rivers.