陕北长城沿线地区1986-2000年沙漠化动态变化分析

 以毛乌素沙地的东南缘部分——陕北长城沿线地区为研究区,以1986—2000年沙漠化动态数据为依据,分析了陕北长城沿线20世纪80年代中期到2000年沙地变化情况。结果表明:该地区14 a来沙漠化土地减少735.1 km2,局部处于稳定的逆转过程,沙地逆转以半固定沙地和半流动沙地为主。但耕地、草地和林地沙漠化仍非常严重,而且新增沙漠化土地中极重度沙漠化土地所占比例较大。近14 a来,沙漠化逆转的原因主要是人类采取了一系列积极的治理沙地措施和国家政策导向。但是由于人口的增加,滥垦、滥牧和滥樵的继续存在,及大规模煤矿资源开发和治理保护的不相协调,致使土地仍在发生沙漠化。

Analysis on Desertification Dynamics based on Remote Sensing and GIS in Zone along the Great Wall in Northern Shaanxi Province

The study area, a part of the southern Mu Us Sandland, is located along the Great Wall in northern Shaanxi Province. Based on database of desertification dynamics from 1986 to 2000, the changes of the sandland were analyzed. The results show that the desertified land had decreased 735^1 km~(2) from 1986 to 2000 and keep stable reversed situation as a whole. The reversed lands are mainly semi-fixed and semi-shifting sand lands. At the same time, the desertification of arable land, grassland and forest land became very severe. Further, the extremely severe decertified land covers the majority among the increased decertified lands. In the past 14 years, the reason of land desertification being reversed is that a series of positive sand-control measures and governmental policy have been adopted. Nevertheless, land resource is still in desertification process because of unreasonable agricultural practices, heavy livestock grazing and firewood cutting, and the disharmony between coal-mine-resources exploitation and environmental protection.