Juha Järvelä

TL;DR: In this article, the authors investigated how type, density and placement of vegetation, flow depth and velocity influence friction losses in a laboratory flume, and showed that leaves on willows seemed to double or even triple the friction factor compared to the leafless case despite the fact that the bottom was growing sedges.

TL;DR: In this article, a new data set of mean velocity profiles and turbulence characteristics is reported from experiments with wheat, and a new definition for the shear velocity based on the deflected plant height is suggested, which enhances the practical applicability of the approach.

TL;DR: In this article, the current state-of-the-art for the parameterization of vegetative form drag and associated flow resistance was explored with a view on practical applicability, and it was shown that describing the key hydraulic properties of plants, geometry, and flexibility with species-specific parameters is superior to the rigid cylinder analogy commonly used in hydraulic engineering practice.

TL;DR: In this paper, a new procedure has been developed which allows the determination of friction factor f or Manning's n using measurable characteristics of vegetation and flow, which is capable of predicting flow resistance due to: (1) leafless bushes or trees and (2) leafy shrubs or trees.

TL;DR: In this article, a model for estimating the vegetative friction factor using the linear superposition of the foliage and stem drag was developed, where the model is separately described with physically based parameters: drag coefficients, reconfiguration parameters, and leaf area and frontal-projected stem area per ground area.