中东亚干旱区土地覆盖变化和人类占用强度变化特征

摘要

研究中东亚干旱区2001-2013年期间土地覆盖变化特征和人类活动对潜在自然植被的影响程度,对保护生态环境和合理利用土地资源具有重要意义.本研究首先基于气象数据和综合顺序分类法(comprehensive and sequential classification system,CSCS)模型模拟了中东亚干旱区的潜在自然植被分布状况,其次基于2001-2013年的MODIS土地覆盖数据集分析了土地覆盖变化情况,最后在前两者的基础上研究了潜在自然植被的人类占用强度及其变化特征.结果表明,1)潜在自然植被以林地、草地、冻原、荒漠四大类为主;2)中东亚干旱区土地覆盖变化较大,其中中亚灌丛面积波动增加,中国华北干旱区农田面积扩张明显,蒙古国中西部灌丛和草地覆盖面积明显减少;3)研究区人类占用强度增强.其中,2010 2013年增长较为明显,4年间人类占用面积占研究区面积的比例增长了1.45％.潜在草地人类占用比例在2009-2013年间增幅最大,为2.88％;潜在林地人类占用比例在2001-2005年间增幅最大,为6.99％.4)在北哈萨克斯坦三州(北哈萨克斯坦州、阿克莫拉州、库斯塔奈州),人口迁移是潜在自然植被人类占用强度变化的主要因素,2006-2013年间人类占用强度比例增长了11.38％;中国的呼伦贝尔和山西干旱区,农业开发是人类占用强度增大的主要因素,2001-2013年间人类占用强度比例分别增长了6.62％和17.64％.%This paper aimed to study the characteristics of land cover change and the impact of human activities on potential natural vegetation (PNV) in the arid region of Central-East Asia.This information is of great significance for the protection of the ecological environment and the rational use of land resources.Firstly,the study simulated the distribution of PNV in the arid region of Central-East Asia based on meteorological data and a CSCS model.Secondly,the study analysed the land cover change based on the 2001-2013 MODIS land cover datasets.Finally,we studied the variation characteristics of human occupancy intensity on PNV.The results showed that:1) the PNV in the arid region of Central-East Asia included potential forestland,potential grassland,potential tundra,and potential desert;2) the shrubland increased dynamically in Central Asia,the croplands expanded significantly in the arid region of China,and the areas of shrubland and grassland in the middle and west of Mongolia decreased;3) the human occupancy increased in the study area.The human occupancy proportion of the study area was notably increased by 1.45％ from 2010 to 2013.The human occupancy proportion of the potential grassland showed the largest increase (2.88％) from 2009 to 2013 and the human occupancy proportion of the potential forest showed the largest increase (6.99％) from 2001 to 2005;4) in the North Kazakhstan Tri-State(Солтустiк Казакстаноблысы,Акмолаоблысы,Костанайоблыс ы),migration was the major factor that affected PNV,as the human occupancy proportion increased by 11.38％ from 2006 to 2013;in the arid regions of Hulunbuir and Shanxi,agricultural development was the main factor for increased human occupancy,which increased by 6.62％ and 17.64％,respectively,from 2001 to 2013.