DOI: 10.1002/2013JD020632
论文题名: Estimating aerodynamic roughness over complex surface terrain
作者: Nield J.M. ; King J. ; Wiggs G.F.S. ; Leyland J. ; Bryant R.G. ; Chiverrell R.C. ; Darby S.E. ; Eckardt F.D. ; Thomas D.S.G. ; Vircavs L.H. ; Washington R.
刊名: Journal of Geophysical Research Atmospheres
ISSN: 21698996
出版年: 2013
卷: 118, 期: 23 起始页码: 12948
结束页码: 12961
语种: 英语
英文关键词: aerodynamic roughness
; sediment entrainment
; spectral analysis
; surface roughness
; terrestrial laser scanning (TLS)
; wind erosion
Scopus关键词: Aerodynamics
; Dust
; Erosion
; Estimation
; Forecasting
; Spectrum analysis
; Steel beams and girders
; Surface roughness
; Aerodynamic roughness
; Aerodynamic roughness length
; Complex surface terrain
; Morphological elements
; Sediment entrainments
; Small-scale surface roughness
; Terrestrial laser scanning
; Wind erosions
; Surveying instruments
; aerodynamics
; complex terrain
; data set
; dust
; entrainment
; numerical model
; sediment transport
; shear flow
; spectral analysis
; surface roughness
; wind erosion
; wind velocity
英文摘要: Surface roughness plays a key role in determining aerodynamic roughness length (zo ) and shear velocity, both of which are fundamental for determining wind erosion threshold and potential. While zo can be quantified from wind measurements, large proportions of wind erosion prone surfaces remain too remote for this to be a viable approach. Alternative approaches therefore seek to relate zo to morphological roughness metrics. However, dust-emitting landscapes typically consist of complex small-scale surface roughness patterns and few metrics exist for these surfaces which can be used to predict zo for modeling wind erosion potential. In this study terrestrial laser scanning was used to characterize the roughness of typical dust-emitting surfaces (playa and sandar) where element protrusion heights ranged from 1 to 199 mm, over which vertical wind velocity profiles were collected to enable estimation of zo . Our data suggest that, although a reasonable relationship (R2 > 0.79) is apparent between 3-D roughness density and zo , the spacing of morphological elements is far less powerful in explaining variations in zo than metrics based on surface roughness height (R2 > 0.92). This finding is in juxtaposition to wind erosion models that assume the spacing of larger-scale isolated roughness elements is most important in determining zo . Rather, our data show that any metric based on element protrusion height has a higher likelihood of successfully predicting zo . This finding has important implications for the development of wind erosion and dust emission models that seek to predict the efficiency of aeolian processes in remote terrestrial and planetary environments. Key Points TLS morphological roughness explains over 90% aerodynamic roughness variance Element protrusion height is more important than spacing Height can be used to estimate aerodynamic roughness for dust emission models ©2013. American Geophysical Union. All Rights Reserved. 资助项目: NE/H021841/1
; RG090467
Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/63124
Appears in Collections: 影响、适应和脆弱性 气候减缓与适应
There are no files associated with this item.
作者单位: Geography and Environment, University of Southampton, Highfield, Southampton, SO17 1BJ, United Kingdom; School of Geography and the Environment, Oxford University Centre for the Environment, University of Oxford, Oxford, United Kingdom; Department of Geography, University of Sheffield, Sheffield, United Kingdom; School of Environmental Sciences, University of Liverpool, Liverpool, United Kingdom; Department of Environmental and Geographical Science, University of Cape Town, Cape Town, South Africa; School of Geography, Archaeology and Environmental Studies, University of the Witwatersrand, Johannesburg, South Africa
Recommended Citation:
Nield J.M.,King J.,Wiggs G.F.S.,et al. Estimating aerodynamic roughness over complex surface terrain[J]. Journal of Geophysical Research Atmospheres,2013-01-01,118(23)