近30 a来毛乌素沙地及其周边地区沙漠化动态变化过程研究

 使用1977年和1986年的沙漠化数据以及2000年和2005年的遥感影像来分析毛乌素沙地及其周边地区在不同时期的沙漠化土地空间分布以及动态变化过程。为了使各个时期的数据具有可比性,采用了与1977年和1986年相同的沙漠化程度分类方法,建立遥感判读标志,采用目视解译的方法得到了2000年和2005年的沙漠化数据。结果显示,自1977年以来毛乌素沙地及周边地区3种程度的沙漠化土地面积都呈持续下降趋势,且轻度沙漠化土地面积减少最快;总沙漠化土地面积在1986—2000年减少的最快;就沙漠化土地的空间分布而言,各个时期都主要集中分布在自然条件较差的鄂托克旗、鄂托克前旗和乌审旗;在1977—2005的近30 a间,各个旗、县的沙漠化土地面积也都持续减少,无论时间上还是空间上,研究区的沙漠化土地都处于全面逆转阶段。

Dynamic Process of Aeolian Desertification Land Variation in Mu Us Sandy Land and Its Surrounding Area in Recent 30 Years

In this paper, the aeolian desertification land data of 1977 and 1986 and the satellite images in 2000 and 2005 are used to analyze the spatial distribution and dynamic variation process of aeolian desertification land in Mu Us sandy land and its surrounding area during different periods. In order to make the aeolian desertification land data of different periods comparable, we interpret satellite images in 2000 and 2005 visually according to the same criterions as how 1977 and 1986 data was obtained. The results show that the area of aeolian desertification land was keeping a decreasing trend in this area since 1977, and the light aeolian desertification land had the fastest decreasing speed, the moderate had the second and the severe had the slowest decreasing speed. The total area of aeolian desertification land decreased fast during 1986—2000. As for the spatial distribution of aeolian desertification land, the most concentrated in arid Otog Banner, Otog Front Banner and Wxin Banner. During 1977—2005, the area of aeolian desertification land decrease continuously in all counties or banners, which showed the status of aeolian desertification here kept reversing temporally and spatially.