1. Numerical modelling of the wind over forests: roughness versus canopy drag
- Author
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Tobias Klaas, Andrey Sogachev, Mark C. Kelly, Ebba Dellwik, Paul Kühn, and Dalibor Cavar
- Subjects
Atmospheric Science ,010504 meteorology & atmospheric sciences ,0208 environmental biotechnology ,Flow (psychology) ,Terrain ,02 engineering and technology ,lcsh:QC851-999 ,Atmospheric sciences ,01 natural sciences ,Wind speed ,lcsh:Science ,0105 earth and related environmental sciences ,Wind power ,business.industry ,Turbulence ,Ecological Modeling ,Vegetation ,Pollution ,lcsh:QC1-999 ,020801 environmental engineering ,Geophysics ,Drag ,Environmental science ,lcsh:Q ,lcsh:Meteorology. Climatology ,business ,lcsh:Physics ,Level of detail - Abstract
Parameterizing the effect of vertically-distributed vegetation through an effective roughness (z0,eff) – whereby momentum loss through a three-dimensional foliage volume is represented as momentum loss over an area at one vertical level – can facilitate the use of forest data in flow models, to any level of detail, and simultaneously reduce computational cost. Results of numerical experiments and comparison with observations show that a modelling approach based on z0,eff can estimate wind speed and turbulence levels over forested areas, at heights of interest for wind energy applications (∼60 m and higher), but only above flat terrain. Caution must be exercised in the application of such a model to zones of forest edges. Advanced flow models capable of incorporating local (distributed) drag forces are recommended for complex terrain covered by forest.
- Published
- 2020