How stand tree motion impacts wind dynamics during windstorms
| Autor: | Sylvain Dupont, Jean-Marc Bonnefond, D. Garrigou, Pauline Défossez, M. Irvine |
|---|---|
| Přispěvatelé: | Interactions Sol Plante Atmosphère (ISPA), Ecole Nationale Supérieure des Sciences Agronomiques de Bordeaux-Aquitaine (Bordeaux Sciences Agro)-Institut National de la Recherche Agronomique (INRA), ANR TWIST, Institut National de la Recherche Agronomique (INRA)-Ecole Nationale Supérieure des Sciences Agronomiques de Bordeaux-Aquitaine (Bordeaux Sciences Agro), Interactions Sol Plante Atmosphère (UMR ISPA) |
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
0106 biological sciences
Atmospheric Science wind-tree interaction 010504 meteorology & atmospheric sciences [SDV]Life Sciences [q-bio] Flow (psychology) canopée Edge (geometry) maritime pine Atmospheric sciences 01 natural sciences Wind speed Physics::Fluid Dynamics forest forêt résistance au vent Astrophysics::Solar and Stellar Astrophysics wind storm Physics::Atmospheric and Oceanic Physics thunderstorm 0105 earth and related environmental sciences edge flow canopy dégât dû au vent Global and Planetary Change pinus pinaster Turbulence turbulence Mode (statistics) Forestry Storm wind damage tempête 15. Life on land wind resistance Vibration Tree (data structure) forest wind damage tree motion 13. Climate action Physics::Space Physics Environmental science Agronomy and Crop Science 010606 plant biology & botany |
| Zdroj: | Agricultural and Forest Meteorology Agricultural and Forest Meteorology, Elsevier Masson, 2018, 262, pp.42-58. ⟨10.1016/j.agrformet.2018.06.022⟩ |
| ISSN: | 0168-1923 |
| DOI: | 10.1016/j.agrformet.2018.06.022⟩ |
| Popis: | Understanding how wind and trees interact during wind storms is crucial for better predicting forest wind damage. The complexity of this interaction is enhanced by the fragmented environment of forests. Here, we present an unprecedented field experiment (TWIST) where both the wind dynamics and the tree motion in the edge region of a maritime pine forest have been recorded simultaneously during four non-destructive wind storms. For three of them, the instrumented trees were under stand flow while for one of them they were under an edge flow. Our measurements demonstrate that the well-known characteristics of stand-flow dynamics remain valid under high wind conditions. Only the sub-canopy flow appeared more intermittent as canopy-top turbulent structures penetrate easier within the canopy due to the tree foliage reconfiguration. Under similar storm intensity, the tree motions were lower under edge flow than under stand flow due to the lower turbulence of the former flow while the mean wind speed was higher. This result demonstrates the importance of considering both the turbulence and the mean wind speed in wind risk models. No impact of tree motion other than tree reconfiguration were observed on the stand flow dynamics. On the other hand, for the edge flow, our measurements reveal a peak in frequency on the wind velocity fluctuations related to the fundamental tree vibration mode. This peak was especially visible at canopy top and in the upper trunk space under high wind conditions. Compared to the stand flow, we suspect that the velocity fluctuations induced by the tree motion emerge in the edge flow due to the lower background turbulence. Our edge storm was nonetheless not strong enough for tree motion to enhance flow turbulence and for trees to enter into resonance. These findings may suggest a higher susceptibility of near-edge trees to reach resonance than stand trees due to the motion of upwind trees in a lower background turbulence. |
| Databáze: | OpenAIRE |
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