TURBULENCE INTENSITY IN OPEN-CHANNEL FLOWS WITH SUBMERGED FLEXIBLE VEGETATION

A number of empirical and semi-empirical models for vertical profiles of turbulence intensities in smooth-and rough-bed flows, such as gravel-bed rivers, have been developed in recent years. However, no models describing turbulence intensity profiles in vegetated channels have yet been proposed. This paper presents a new multi-segment approach used to model turbulence intensities in vegetated channels. Within this framework, different concepts are applied to specific flow regions and the overall turbulence intensity profile is represented with a set of linked segments. As a result, a set of turbulence intensity models for flow regions within and above the vegetation canopy are given. The models have been tested using extensive laboratory experiments covering wide ranges of background flow and vegetation parameters. The analysis also focused on identification of the effects of flow and roughness parameters on the model coefficients and overall performance.