Dune sand transport as influenced by wind directions, speed and frequencies in the Ordos Plateau, China
Dune sand transport as influenced by wind directions, speed and frequencies in the Ordos Plateau, China
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DOI：
10.1016/j.geomorph.2004.10.005
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发表时间：
2005-04
期刊：
影响因子：
3.9
通讯作者：
Lianyou Liu;E. Skidmore;E. Hasi;L. Wagner;J. Tatarko
中科院分区：
文献类型：
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作者：
Lianyou Liu;E. Skidmore;E. Hasi;L. Wagner;J. Tatarko
鄂尔多斯高原是我国风蚀面积大、荒漠化严重、风沙危害严重的地区。为了确定该地区的风沙输送，通过对曲布齐沙漠和毛乌素桑迪的实地观测，建立了该地区风沙输送率与10 min风速的关系。通过实地观测，估算了移动的、半固定和固定沙丘表面的临界风速（距地面2 m）。输沙率随裸地率和近床风速的增大而增大。高分辨率的气象10分钟平均风速数据在10米以上的地面被转换成速度值在2米的高度，以计算沙输运潜力的基础上的三个具体参数的决定性输沙：风速，持续时间和方向。计算了不同风速水平和风向下的风沙输移量，并利用矢量运算技术确定了不同沙丘表面类型风沙输移的总体特征。输沙风主要发生在春季。主导风向为W、WNW和NW，出现频率均在60%以上，其中以W、WNW和NW向为主的输沙量占总输沙量的70%以上，相当于研究区风沙总体向东南方向侵蚀。风速与频率的关系可用幂函数表示。高强度大风出现频率较低，但在风沙输送中起主导作用。
The Ordos Plateau in China is a region with extensive wind erosion, severe desertification and various aeolian sand hazards. In order to determine aeolian sand transport in this region, the relationship between the sand transport rate and wind speed at 10 min frequencies was established by field observation in both the Qubqi Sand Desert and the Mu Us Sandy Land. Threshold wind speeds (2 m above the ground) for mobile, semi-fixed and fixed dune surfaces were estimated by field observations. The sand transport rate increased with the increase of the bare land ratio and near-bed wind speed. High-resolution meteorological 10 min average wind velocity data at 10 m above the ground were converted into velocity values at a height of 2 m to calculate sand transport potential based on three specific parameters decisive for sand transport: wind speed, duration and direction. The quantity of aeolian sand transported was calculated for various wind speed levels and directions, and the overall characteristics of sand transport on different dune surface types were determined by vector operation techniques. Sand transporting winds took place mainly in springtime. The prevailing wind directions were W, WNW and NW, with a frequency of more than 60% in total, and sand transport in these directions made up more than 70% of the total transport, corresponding to a general southeastward encroachment of aeolian sand in the study area. The relationship between wind frequency and speed can be expressed by a power function. High magnitude strong winds had a low frequency, but they played a dominant role in aeolian sand transport.