Field determination of drag forces and shear stress partitioning effects for a desert shrub (Sarcobatus vermiculatus, greasewood)
| Autor: | John A. Gillies, William G. Nickling, Nicholas Lancaster, D. M. Crawley |
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| Rok vydání: | 2000 |
| Předmět: |
location.dated_location
Atmospheric Science Drag coefficient Planetary boundary layer ved/biology.organism_classification_rank.species Soil Science Aquatic Science Oceanography Deserts and xeric shrublands Shrub location Geochemistry and Petrology Earth and Planetary Sciences (miscellaneous) Shear stress Earth-Surface Processes Water Science and Technology Hydrology Ecology biology ved/biology Paleontology Forestry biology.organism_classification Geophysics Space and Planetary Science Drag Environmental science Greasewood Larrea |
| Zdroj: | Journal of Geophysical Research: Atmospheres. 105:24871-24880 |
| ISSN: | 0148-0227 |
| DOI: | 10.1029/2000jd900431 |
| Popis: | Drag coefficients (Cd) for the desert shrub greasewood (Sarcobatus vermiculatus) were developed from force versus wind speed data collected with an omnidirectional force balance. The average Cd for a small (0.6 m high, 0.5 m wide) shrub and a larger (1.6 m high, 1.3 m wide) shrub were 1.425 (±0.103) and 0.435 (±0.200), respectively. These values are much larger than similarly shaped solid elements and previously reported values for creosote bush (Larrea tridentata, Cd = 0.485) and an artificial tree (0.4). The greater Cd value for greasewood probably results from factors related to porosity and vegetation structure that gives this shrub-type greater momentum extracting potential. The drag coefficients for the greasewood shrubs were found to show dependence upon flow Reynolds numbers >6×105, corresponding to wind speeds greater than 18 m s−1 at 10 m. The developed greasewood Cd values were used in a shear stress partitioning model that indicated they would be extremely effective at reducing wind-generated sediment transport at low-percent coverage. |
| Databáze: | OpenAIRE |
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