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中国沙漠 ›› 1985, Vol. 5 ›› Issue (3): 3-11.

• 论文 •    下一篇

中国北方沙漠化现状及发展趋势

朱震达   

  1. 中国科学院兰州沙漠研究所
  • 出版日期:1985-09-20 发布日期:1985-09-20

Status and Trend of Desertification in Northern China

Zhu Zhenda   

  1. Institute of Desert Research, Academia Sinica, Lanzhou
  • Online:1985-09-20 Published:1985-09-20

摘要: 通过研究,对中国北方沙漠化的现状及趋势得出如下结论:(1)中国北方沙漠化土地的面积为33.4万平方公里,其中已经沙漠化了的土地为17.6万平方公里,潜在沙漠化土地为15.8万平方公里。在已经沙漠化的土地中,属于沙质草原沙漠化发展的土地占42.2%,固定沙丘活化的占52.2%,沙丘前移入侵的占5.5%。(2)按其成因来看,以草原过度农垦为主的占25.4%,以过度放牧为主的占28.3%,以过度樵柴为主的占31.8%,其他则系水资源利用不当和工矿交通建设破坏植被所形成,风力作用下沙丘前移所形成的沙漠化土地仅占5.5%,可见在沙质地表和干旱多风气候条件下沙漠化发展的主要因素是人为作用,因此,调整现有土地利用结构,合理利用资源便是防止沙漠化发展的基本途径.(3)从沙漠化发展程度来看,在已经沙漠化的土地中严重沙漠化土地占19.3%,强烈发展中的沙漠化土地占34.7%,正在发展中的沙漠化土地占46.0%。特别是农牧交错的草原农垦区沙漠化的发展大部分是在50年代以来所形成,更应引起注意.(4)从发展趋势来看,根据50年代末与70年代末航空相片的对比分析,25年来沙漠化土地增加了3.9万平方公里,平均每年扩大1,560平方公里,这些扩大的土地是沙质草原的农垦和固定沙地农垦、樵采及过牧所引起的沙丘活化。

Abstract: In Northern China, the area of desertification is about 334, 000 sq. km., of which, 176, 000 sq.km.has already been desertified and 158, 000 sq.km.is being threatened by latent dangers. In talking about the area which has already been desertified, 42.2% was caused by the spread of desertification on sandy steppe; 52.3% was resulted from the activation of fixed dunes and 5.5% was brought about by the encroachment of dunes. In consideration of the causations of desertification, 25.4% of the desertification is brought into the world by over-cultivation of steppe; 28.5% was produced by over-grazing; 31.8% was originated under the influence of the collection of fuelwoods; 9% caused by misuse of Water resources and techgenic factors and only 5.5% by the encroachment of sand dunes under windforce. By analyzing the above-mentioned percentage, it can be seen that the anthropological effects are the principle factors to develop desertification under the conditions where the surface is composed of sandy texture and the climate is characterized by drought and frequent winds. Therefore, the change of land use types and rational utilization of resources are the two fundamental steps to stop the development of desertification. From the viewpoint of the developmental degree of desertification, it is classified as following percentage that 19.3% of the already-desertified lands belongs to the most severe desertified land) 34.7% belongs to the severe desertified land and the on-going desertified land occupies 46.0% of that. particularly, it is worth to mention that the development of desertification in the marginal area (transitional zone of agriculture and range-land)is mostly formed in 1950s and more cares should be paid to the issue. According to the developmental trend, desertified lands, on the basis of contrastive analysis of aerial photographs in late 1950s and late 1970s, increased 39, 000 sq.km., namely the annual increasement of desertific-cation in Northern china is 1560 sq.km.,The enlargements of desertification are caused by both the reclamation of sandy steppe and opens of vegetated dunes and the activation of dune under the influence of fuelwood collection and over-grazing.