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中国沙漠 ›› 2004, Vol. 24 ›› Issue (3): 306-312.

• 论文 • 上一篇    下一篇

敦煌莫高窟顶灌木林带防护效应研究

汪万福1,2, 李最雄2, 刘贤万1, 郑彩霞3   

  1. 1. 中国科学院 寒区旱区环境与工程研究所, 甘肃 兰州 730000;
    2. 敦煌研究院, 甘肃 敦煌 736200;
    3. 北京林业大学, 北京 100081
  • 收稿日期:2003-08-10 修回日期:2003-10-19 出版日期:2004-06-20 发布日期:2004-06-20
  • 作者简介:汪万福(1966-),男(汉族),甘肃甘谷人,副研究员,在职博士,主要从事石窟遗址环境保护和壁画保护修复研究。E-mail:wwanyu@hotmail.com
  • 基金资助:
    国家重点基础研究发展规划项目(G2000048705); 国家文物局文物保护科学和技术研究课题(9907); 国家计委、水利部([1998]1110号)资助

Sheltering Effect of Shrub Shelterbelt at Top of the Mogao Grottoes

WANG Wan-fu1,2, LI Zui-xiong2, LIU Xian-wan1, ZHENG Cai-xia3   

  1. 1. Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China;
    2. Dunhuang Academy, Dunhuang 736200, Gansu Province, China;
    3. Beijing Forestry University, Beijing 100081, China
  • Received:2003-08-10 Revised:2003-10-19 Online:2004-06-20 Published:2004-06-20

摘要: 风洞模拟实验和野外观测结果表明, 平均林带高H=1.5m, 疏透度β=50%的两条灌木林带周围的气流场分为7个能量区。在贴地层, 有林带前的拐角绕流阻滞减速区, 林带中的灌丛阻挡湍流衰减区, 林带后的回流涡旋减速及速度恢复区, 林带远方的气流附体加速区。在林带上部, 有林带间的阻滞减速区和林带后的涡旋减速区, 在林带顶后部有集流加速区。风沙流在阻滞、涡旋回流减速区沉积, 而在加速区则会产生风蚀, 在林带顶上下层气流交换加强。在低速时林带阻沙能力较强, 当风速为10m·s-1时, 有林带的输沙量可减少一个量级, 即阻滞90%的风沙流; 在中高风速时(风速为15m·s-1及以上), 林带对风沙流的阻滞作用明显减弱, 只阻滞20%。

关键词: 敦煌莫高窟, 防沙治沙, 防护林带, 防护效应, 实验研究

Abstract: Both wind tunnel experiment and field observation indicate that the wind regime around two shrub shelterbelts at average 1.5 m high and with a porosity of about 50% can be separated into 7 energy zones. In the near-surface layer, there are the circumambulating-blocking speed-down zone at the front corner of shelterbelt, the turbulent weakening zone blocked by shrubs inside the belt, the circumfluence whirling speed-down and then speed-up zone behind the belt, and the accelerating zone far away from the belt; In the upper layer, there are the blocking speed-down zone inter-belt, the whirling speed-down zone behind the belt, the conflux accelerating zone just behind the top of shelterbelt. The sands blown by wind accumulate in the speed-down zones while wind erosion occurs in the speed-up zones. The vertical air transfer is intensified at the top of the forest. Shelter forest belt can more effectively hinder blown sand at lower wind speed than at middle-to-higher wind speed, for example, 90% of sand flow has been hindered at 10 m·s-1; whereas, only 20% has been hindered at ≥15 m·s-1.

Key words: Dunhuang Mogao Grottoes, shelter forest belts, shelting effect, experimental study

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