科尔沁沙地荒漠化土地初析

应用1996年TM卫星影像资料得出，科尔沁沙地中心地区荒漠化土地占总土地面积的34．02％，以风蚀荒漠化土地为主。各种荒漠化土地在14个旗（县）的分布不同，按严重程度划分为重度荒漠化地区、中度荒漠化地区和轻度荒漠化地区。对历史时期和近期的分析表明，科尔沁沙地荒漠化土地产生和扩展的根本原因是过度开垦。

Desertified Land Analysis in Horqin Sandy Land

According to the TM Satellite Image Map taken in 1996 of Horqin Sandy Land, the area of fourteen banners and countries located in central Horqin Sandy Land is 11.3945 million hm2, which includes permanent farmlands 2.8141 million hm2, mountain lands 2.502 million hm2, grasslands without any desertification 1.0608 million hm2, forestlands excluding windbreak network of farmlands 0.61 million hm2, water areas 0.3198 million hm2, public lands 0.2116 million hm2, and desertification lands 3.8762 million hm2. 　　Of above-mentioned desertification lands, there are 3.2873 million hm2 wind erosion lands, 0.1162 million hm2 water erosion lands and 0.4727 million hm2 desertification salt-alkali lands. 　　In accordance with the above-mentioned figures, it is obvious that to prevent lands from wind erosion is the main work on prevention and cure of desertification of Horqin Sandy Land. And of the wind erosion lands, moving and semi-moving dunes is 0.9201 million hm2, desertification grasslands is 1.4933 million hm2, and desertification farmlands is 0.8739 million hm2. 　　According to the proportion of desertification land area divided by total land area, the degree of desertification of the above-mentioned fourteen banners and countries can be clustered into three grades: severe desertification land, proportion>40%, including seven banners; middle desertification land, proportion between 20%～40%, including four banners; light desertification land, proportion <20%, including three banners. 　　According to the analysis on the evolution of Horqin Sandy Land in ancient and modern time, it can be concluded that the main reason of land desertification is the over reclamation.