Vertical distribution of grain size for wind blown sand
Vertical distribution of grain size for wind blown sand
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DOI：
10.1016/j.aeolia.2012.03.003
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发表时间：
2012-12-01
期刊：
影响因子：
3.3
通讯作者：
Li, B.
中科院分区：
文献类型：
--
作者：
Farrell, E. J.;Sherman, D. J.;Li, B.
颗粒大小分选特性从25个垂直，质量通量剖面的混合谷物人口从Jericoacoara，巴西进行的实地研究。垂直质量通量分布最好用指数衰减函数来描述。粒度统计的分析表明，粒度趋势的逆转发生在位于0.05-0.15米以上的床的拐点区。低于这个拐点，平均粒度急剧下降，在近床区主要由爬行和跃移运输方式的海拔。在拐点以上，随着海拔的升高，晶粒尺寸变粗。海拔越高，分选越好。偏度和峰度与海拔之间没有很强的关系。在某些自然环境中，地表以上的粒度拐点是跃移的一个特征，对颗粒轨迹的数值模拟具有重要意义。(C)出版社：Elsevier B. V.
Grain size-sorting characteristics from twenty-five vertical, mass-flux profiles for a mixed grain population are presented from a field study conducted in Jericoacoara, Brazil. The vertical mass flux profile is best described using an exponential decay function. An analysis of the grain-size statistics shows that a reverse in grain-size trends occurs at an inflection zone located 0.05-0.15 m above the bed. Below this inflection, mean grain-size decreases steeply with elevation in the near bed region dominated by reptation and saltation modes of transport. Above the inflection there is a coarsening of grain size with elevation. Sorting improves with elevation above the surface. There is not a strong relationship between skewness and kurtosis with elevation. The grain-size inflection above the surface is a characteristic of saltation in some natural environments, with important implications for numerical modeling of grain trajectories. (C) 2012 Published by Elsevier B.V.