1980s-2005 年内蒙古地区土地利用/覆被变化分析

近几十年来, 由气候变化和人类活动共同驱动的内蒙古地区土地利用/覆被变化(LUCC)较为剧烈, 其引发了一系列的生态环境问题。本文基于3 期LUCC数据, 借助于变化率指数、动态度指数、转类矩阵, 在全区和地级市尺度上, 分析了内蒙古地区土地利用/覆被变化的时空特征及驱动因素。研究结果显示, 受地形因素的影响, 研究区土地利用/覆被变化表现出明显的区域差异及区域趋同性。在经济发展和人口增长的双重压力下:(1)平原耕作区深受国家宏观政策的影响, 2000 年之后的“林地、高覆盖草地开垦”总体速度下降了近35%;(2) 平原耕作区北部边缘条带状地区、山区草原区受制于降水不显著的波动呈减少态势, 2000 年之后的“草地退化及荒漠化”趋势加强了近85%。研究结果为内蒙古地区土地资源的可持续利用与科学管理提供了依据。

Study on Land Use/Cover Changes in the Inner Mongolia Autonomous Region from 1980s to 2005

In the past decades, climate change and human activities accelerated land use/land cover change and then promoted regional environmental changes in the Inner Mongolia Autonomous Region. In this article, we describe spatial and temporal characteristics and analyze driving factors of land use/land cover changes on regional and prefectural scales according to three periods of land use/land cover data, conversion rates, dynamic degree and the converted matrix. The result shows that, there are obvious regional differences and similarities in changes of land use/land cover in the Inner Mongolia Autonomous Region, which affected by topographic factors. (i) From 1980s to 2000, the main changes of land use/land cover are grassland reclamation at plain cultivation areas (94 000 hm²/a) and grassland degradation and desertification at highland steppe areas (72 000 hm²/a), which is owing to climate change, population growth and a series of political and economic macro-policy; (ii)The reclamation of cultivated land had been strongly controlled in plain cultivation areas by the "Grain for Green" policy since 2000, while the tends of grassland degradation and desertification in the banded regions at the northern edge of the plain cultivation areas (11 000 hm²/a) and highland steppe areas (133 000 hm²/a) had been increased, which is affected by the precipitation fluctuations and population growth factors. The result indicates that, plain cultivation areas become more susceptible to national macroeconomic policies, and highland steppe areas become more susceptible to changes of precipitation, which is under big pressure of economic development and population growth. These findings provide a basis for the sustainable use and the scientific management of land resources in the Inner Mongolia Autonomous Region.