IMPACT OF VEGETATION GROWN AROUND THE FILTER UNITS ON THE RIVER REVETMENT

Abstract

 The vegetation growth on the sediment deposited around the filter unit (FU) can be expected to provide ecological habitat, improve the landscape, and protect the revetment. Hydraulic experiments and numerical simulations on the vegetation around the filter units placed in a row were conducted to investigate the impact of vegetation on the river revetment. As a result, it was shown that even the vegetation lodging during the flood could reduce the surrounding flow velocity by about 40% and protect the revetment. The water level rise during floods was about 0.1 m. On the other hand, the riverbed scouring increased due to the impact of vegetation. The range of sediment outflow from the FU base was less than half the width of the FU, and the FU itself would not incline and sink. The vegetation growing around the FUs is effective in protecting the revetment at the water-colliding front in small-to-medium-sized rivers.