鄂托克旗风蚀荒漠化景观格局动态变化研究

利用鄂托克旗2000年和2005年TM遥感影像,对荒漠化土地进行判读,结合实地调查,并根据中国“三北”地区荒漠化区域分类与发展趋势综合研究野外地质调查内容-技术要求,确定土地荒漠化景观类型和荒漠化程度,将研究区风蚀荒漠化分为轻度沙化、中度沙化、重度风蚀和严重风蚀4个类型。应用Arcview3.3对两期TM影像进行人机交互判读,得到研究区两个时期的风蚀荒漠化景观类型数据并统计,分析研究区风蚀荒漠化景观格局的动态变化。结果表明,未荒漠化土地主要集中在研究区的北部,严重风蚀主要集中在研究区的南部,由北向南,风蚀程度逐渐加重。研究区风蚀荒漠化主要以轻度沙化和中度沙化为主,占研究区风蚀面积的70%以上,破碎度有所增大。风蚀荒漠化面积虽有减小,但风蚀呈加剧趋势。盐渍化土地已转化为风蚀荒漠化景观,而风蚀荒漠化景观可以向其他各景观转化。在适当条件下,轻度沙化土地与未荒漠化土地容易相互转化。中度沙化土地和重度风蚀土地容易转变为其他景观。

Dynamic Change of Aeolian Desertification Landscape Pattern in Otog Banner, Inner Mongolia

The TM remote sensing images of Otog Banner in 2000 and 2005 were interpreted to abstract the desertification lands. The results combined with the field survey were used to determine the types and degrees of desertification lands according to the requirements of content-technology in the desertification regionalization of China "three-north" regions. The aeolian lands in study region can be classified as four types: slight desertification, moderate desertification, severe desertification, and very severe desertification. The statistical data on landscape patterns of the study region in two periods were obtained through human-computer interaction interpretation with Arcview3.3 software. Then the dynamic changes of aeolian landscape patterns were analyzed. The results showed that not desertification lands mainly distributed in the north and very severe desertification lands in the south of Otog Banner, with the wind erosion degree increasing from north to south. The area of desertification lands in the study region had decreased, but the wind erosion degree of land increased, and the desertification area of both slight desertification and moderate desertification occupied more than 70% of the erosion area. The former salinized lands had been transformed into aeolian desertification lands. Generally, under proper conditions transformation usually occurred between the slight desertification and non desertification lands, and the middle and the severe types are inclined to the other landscapees.