中国沙漠 ›› 1989, Vol. 6 ›› Issue (1): 25-31.

• 论文 • 上一篇    下一篇


贺大良, 邹本功, 李长治, 张继贤, 邸醒民   

  1. 中国科学院兰州沙漠研究所
  • 出版日期:1986-03-20 发布日期:1986-03-20

A preliminary Study of the Experiment of the physical process of Ground Surface Erosion in Wind Tunnel

He Daliang, Zou Bengong, Li Changzhi, Zhang Jixian, Di Xinmin   

  1. Institute of Desert Research, Academia, Sinica, Lanzhou
  • Online:1986-03-20 Published:1986-03-20

摘要: 本文介绍了研究地表风蚀物理过程中风洞实验的方法、内容及结果。实验表明:净风对土表的风蚀作用微弱,即使在遭到大风吹刮时,土表的结壳仍不易受到破坏。但在挟沙气流作用下,却能使土表结壳遭到破坏,风蚀发展异常迅速。自然形成的土表结壳、经风选被粗化的土表和长有草丛的地表均有抑制风蚀的保护作用。本实验在方法上虽属初步尝试,但能说明沙漠化物理过程的一般机制,并为防治按漠化的措施提供依据。

Abstract: The experimental results of the physical process of ground surface erosion in wind tunnel is presented in the paper. The experiment indicates that wind itself is of weak effect on ground surface erosion, so that the soil crust may not be destroyed even under great wind velocity. But under the effect of sand-bearing current wind erosion developed rapidly. After 10 minutes' attack of sand-bearing current at Beaufort force 5, obvious erosional grooves appeared. After 20 minutes' attack of sandbearing wind at Beaufort force 6, top soil was all blown away, the erosional deptth reached 2 cm and the crust was destroyed. It can be seen in the deflation experiment of adding sands in the current that the thick growth of grass could resist the attack of sand-bearing wind, even if 2-3 cm deep of soil had been blown away and the greater part of grass roots was exposed, the soil body surrounded by the root system could still resist the deflation of sand drift. The experiment also indicates that naturally formed crust and soil surface roughened by many times of blowing can also prevent soil surface from wind erosion But ploughing and trampling by man and animal can intensify, wind erosion. We have compared the crust which had been formed after being watered many times and naturally dried with the sample without such treatment, the erosional amount of the latter was 1.3 times greater than that of the former and the coarseat grain composition was 10.9 times. Once was the crust destroyed by trampling etc., the deflation amount would increase over 10 times, especially, the thinner granule could increase more than 30 times. The deflation amount of the two soil samples was 80 kg/m2 and 57.2 kg/m2 respectively, i. e. 800 ton and 572 ton per hectare after 200 times of simulated ploughingCploughing per 5 minutes), at Beaufort wind force 5. The method used in the above-mentioned experiment is only a preliminary attempt, but it shows the general mechanism of the physical processes of desertification either in the open field or in the wind tunnel. To control shifting sands, protect vegetation, prevent overgrazing and overcultivation, and work out a rational cropping system are, no doubt, effective approaches of combation desertification.