藏北那曲地区草地和未利用土地动态变化及原因

Dynamic Changes and Reason Analysis of Grassland and Unused(Unexploited or Unwrought) Land in Naqu of Northern Tibet

根据1990年和2000年2期那曲土地利用/覆盖分类图,运用GIS的空间分析和数理统计功能,分析那曲地区草地退化和未利用土地的增加情况,并结合气象资料和人口资料分析这些变化的原因。结果表明:10 a间,那曲地区未利用地增加;草地减少,突出表现为草地向未利用地转化。草地向林地和耕地转化,导致这种结果的主要原因是由于人类的社会经济活动造成的,人类社会经济活动引起这一地区土地利用变化的强度已经超过自然因子所能达到的强度,起到了绝对的主导作用。

In this paper, based on two land use and land cover images for the year 1990 and 2000 , the change of grassland regradation area and unused （unexploited or unwrought） land in Naqu of Tibet are analyzed using spatial analysis model and statistic model of GIS. The reasons of these changes are analyzed using the images, meteorologic data and population statistic. The results show that the unused land in Naqu was increased and the grassland was decreased from 1990 to 2000. The primary changes were that grassland was converted into unused land, forest and ploughland. The cause of resulting in these outcomes is mainly impacts of human economic activities on eco-environment. The impacts of human economic activities on land use change in Naqu are more intensive than the impacts of natural facts.