Turbulence characteristics within sparse and dense canopies

  • Laurence Pietri
  • Alexandre Petroff
  • Muriel Amielh
  • Fabien Anselmet
Original Article


Boundary layer interactions with canopies control various environmental processes. In the case of dense and homogeneous canopies, the so-called mixing layer analogy is most generally used. When the canopy becomes sparser, a transition occurs between the mixing layer and the boundary layer perturbed by interactions between element wakes. This transition has still to be fully understood and characterized. The experimental work presented here deals with the effect of the canopy density on the flow turbulence and involves an artificial canopy placed in a fully developed turbulent boundary layer. One and two-component velocity measurements are performed, both within and above the canopy. The influence of the spacing between canopy elements is studied. Longitudinal velocity statistical moments and Reynolds stresses are calculated and compared to literature data. For spacings greater than the canopy height, evidences of this transition are found in the evolution of the skewness factor, shear length scale and mixing length.


Turbulence Canopy flow Mixing layer flow Boundary layer flow Canopy density Spatial heterogeneity 


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Copyright information

© Springer Science+Business Media B.V. 2009

Authors and Affiliations

  • Laurence Pietri
    • 1
  • Alexandre Petroff
    • 1
    • 2
  • Muriel Amielh
    • 1
  • Fabien Anselmet
    • 1
    • 3
  1. 1.I.R.P.H.E.Aix-Marseille Université, C.N.R.S., Technopôle de Château-GombertMarseille Cedex 13France
  2. 2.Air Quality Research DivisionEnvironment CanadaTorontoCanada
  3. 3.Ecole Centrale Marseille, Technopôle de Château-GombertMarseille Cedex 20France

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