从若干典型地区的研究对近十余年来中国土地沙漠化演变趋势的分析

AN ANALYSIS ON THE TREND OF LAND DESERTIFICATION IN NORTHERN CHINA DURING THE LAST DECADE BASED ON EXAMPLES FROM SOME TYPICAL AREAS

土地沙漠化是当前世界上一个重要的生态环境问题,在我国也存在着严重的土地沙漠化问题。50年代末至70年代中期,我国沙漠化土地以每年1560km^2的速度扩大。近10余年来其总的趋势仍在发展,平均每年以2100km^2的速度蔓延。目前,全国已经沙漠化了的土地面积达19.70×10~4km^2以上,其中以沙质草原农垦区和能源基地附近的情况最为严重。实例说明,沙漠化土地在采取必要的措施之后,不仅可以防止其蔓延,而且还可以重新恢复其生产潜力成为农牧业用地。

Nowdays, desertification is the impoverishment of terrestrial ecosystems under the impact of man. Land degradation due to poor management has plagued north China for a long time. Since end of 1950's to the middle of 1970's, the area of degraded land has averagely expanded 1560 sq. km annually, and during the last decade it w as up to 2100 sq. km in Northern China Recently, the total area of degraded land approximates to 197 thousand sq. km. The situation of desertification becomes very serious in expleited land of sandy steppe and the vicinity of coal mines. Howerver, a number of typical examples have proved that some measures for land conservation are feasible and the process of desertification has effectively been controlled. The potential productivity of cultivated land and pasture has gradually been resetored.