Aeolian sediment transport over sandy gobi: Field studies in the Nanhu gobi along the Hami-Lop Nor Railway
Aeolian sediment transport over sandy gobi: Field studies in the Nanhu gobi along the Hami-Lop Nor Railway
复制标题
沙质戈壁上的风沙输送：哈密罗布泊铁路沿线南湖戈壁的实地研究
DOI：
10.1016/j.iswcr.2022.03.009
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发表时间：
2022
影响因子：
6.4
通讯作者：
Lihai Tan
中科院分区：
文献类型：
--
作者：
Tao Wang;Jianjun Qu;Lihai Tan
桑迪戈壁具有丰富的泥沙来源，风沙在戈壁上的传播会造成严重的沙害。然而，相对于有限供沙条件下砾石戈壁风沙运动的研究，桑迪戈壁的风沙运动研究较少，对桑迪戈壁风沙运动的认识还很薄弱。在这里，我们报告的三个传输事件的观测结果桑迪戈壁沿着哈密-罗布泊铁路的基础上，高频跃移颗粒计数和水平泥沙通量的测量与瞬时风速测量。结果表明，与砾石戈壁上明显的间歇性风沙跃移不同，桑迪戈壁上的风沙跃移是连续性的。跃移层平均高度为0.23 ± 0.07 m，无论戈壁类型如何，跃移层高度与地表颗粒物粒径和风速均呈正相关。输沙率可用幂函数Q = ap/g [ u/（u/2 - u/t 2）B]表示，尺度参数（B）达到2.5，远大于其它戈壁区的尺度参数（B = 1）。研究结果表明，桑迪戈壁风沙比砾石戈壁严重，南湖桑迪戈壁是哈密至罗布泊铁路沙害的主要沙源。在桑迪戈壁区，采用加大棋盘格尺寸、提高沙障高度的棋盘格沙障固沙措施应成为哈乐铁路防沙体系的主要研究课题。
Wind-blown sand over sandy gobi with an abundant sediment supply can cause severe sand hazards. However, compared with the study of aeolian transport over gravel gobi with a limited sediment supply, less attention has been devoted to sandy gobi, and thus, our understanding of wind-blown sand movement on sandy gobi is still poor. Here, we report the results of observations of three transport events on a sandy gobi along the Hami-Lop Nor Railway based on high-frequency saltation particle count and horizontal sediment flux measurements coupled with instantaneous wind velocity measurements. The results reveal that, unlike the notably intermittent aeolian saltation over gravel gobi, continuous transport occurred on the sandy gobi. The mean saltation layer height was 0.23 ± 0.07 m, and it was positively related to both the grain size of surface particles and the wind velocity regardless of the gobi type. The sediment transport rates could be expressed as the power function Q = a p/g [ u∗ ( u∗ 2 - u∗t 2 )b, and the scaling parameter (b) reached to 2.5, which is much larger than that of other gobi areas (b = 1). Our findings suggest that the wind-blown sand over sandy gobi is much more severe than that over gravel gobi, and the Nanhu sandy gobi is the major sand source for sand hazards of the Hami-Lop Nor Railway. Sand-fixation measures such as checkerboard sand barriers with enhanced checkerboard size and barrier height should be the main subject of sand control systems for the Hami-Lop Nor Railway in sandy gobi.