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中国沙漠 ›› 2010, Vol. 30 ›› Issue (3): 516-521.

• 沙漠与沙漠化 • 上一篇    下一篇

莫高窟顶戈壁偏东风作用下输沙率变化的观测研究

柳本立1, 张伟民1, 刘小宁1, 张国彬2, 邱 飞2, 詹洪涛2   

  1. 1.中国科学院 寒区旱区环境与工程研究所 敦煌戈壁荒漠生态与环境研究站, 甘肃 兰州 730000; 2.敦煌研究院 保护研究所, 甘肃 敦煌 736200
  • 收稿日期:2009-09-12 修回日期:2010-01-04 出版日期:2010-05-20 发布日期:2010-05-20

Field Measurements of Sand Transport Rate Change under Easterly Wind Condition over Gobi Land atop Mogao Grottoes

LIU Ben-li1, ZHANG Wei-min1, LIU Xiao-ning1, ZHANG Guo-bin2, QIU Fei2, ZHAN Hong-tao2   

  1. 1.Dunhuang Gobi Desert Ecological and Environmental Research Station & Key Laboratory of Desert and Desertification, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China; 2.The Conservation Institute of Dunhuang Academy, Dunhuang 736200, Gansu, China
  • Received:2009-09-12 Revised:2010-01-04 Online:2010-05-20 Published:2010-05-20

摘要: 通过一次沙尘暴天气过程对莫高窟顶不同观测点戈壁风沙流结构和输沙率的时空变化特征进行了系统同步观测。观测表明,偏东风条件下,当风速为10 m·s-1时,水平观测方向上存在一个各点输沙率平衡的阶段,即崖顶戈壁至鸣沙山边缘戈壁各观测点的输沙率相当;当风速大于10 m·s-1时,戈壁地表以风蚀搬运作用为主,出现了戈壁向鸣沙山的长距离风沙搬运;当风速小于10 m·s-1时,戈壁沙物质的长距离搬运作用不明显。不同风况及沙源条件下,风沙流结构和输沙特征会发生显著变化。借鉴Lattau输沙率方程,运用风速和输沙率推算各观测点输沙率的时空变化,计算结果表明,在风速为10 m·s-1左右时,窟顶戈壁带的输送效率约为60%。

关键词: 莫高窟, 戈壁, 风沙运动, 输沙率

Abstract: Based on the simultaneous observational data of wind-sand flow structure over Gobi land during a sand storm, the temporal and spatial variations of sand transport rate and wind-sand flow structure at different observation points atop Mogao Grottoes were measured and analyzed. The result shows that in condition of easterly wind, when wind speed was about 10 m·s-1, there appeared a balanceable stage of sand transport rates in the horizontal direction at different observing points, where the sand transport rates at different points from the cliff to the sand mountain were nearly the same. When wind speed was stronger than 10 m·s-1, the main wind-sand activities were wind erosion and transportation, and long distance transportation of sand material from Gobi land to the Mingsha Mountain was obvious; when wind speed was below 10 m·s-1, the long distance transportation of sand material was not strong. Under different wind speed and sand supply conditions, wind-sand flow structure and sand-transporting character may have significant changes. With the help of Lattau's equation of sand transport rate, we used the data of wind speed and sand transport rate to calculate the temporal and spatial variations of sand transport rates at different observing points. According to the calculation, the transfer efficiency of the Gobi land atop Mogao Grottoes is about 60%.

Key words: Mogao Grottoes, Gobi, wind-sand activity, sand transport rate

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