Abstract
We find sometimes natural waterway with the vegetations. Vegetations play a major role in the ecological environment. On the other hand, vegetations are also the flow resistance. So it is important to estimate the flow resistance for the design of a vegetated waterway. At present, the vegetative resistance is calculated by using the fixed Manning roughness coefficient. However, that method cannot evaluate the vegetative resistance correctly. This research proposed the new Manning roughness coefficient of open channel flow with submerged vegetations from the velocity distribution of the flow. The validity of the new Manning roughness coefficient was verified by the comparison with the experiment.
