三峡库区近十年土地利用变化特征研究

Research on the characteristics of land use change in the Three Gorges Reservoir Area

土地利用变化是人与自然密切联系的重要方式,土地利用格局的变化能够反映人类利用和改造自然等活动的强弱及其周边环境的变化趋势。基于2007、2010、2013和2019年共4期三峡库区的遥感影像,首先通过ENVI软件监督分类功能结合人工目视解译方法提取了耕地、林草地、水域和建设用地4种土地利用类型的面积,其次从土地利用变化速度、转移方向定量分析了三峡库区2007~2019年间的土地利用变化特征,最后探讨了土地利用格局变化的原因。结果表明:1)三峡库区以林草地和耕地为主,2019年两者面积分别占比76%和14%;建设用地和水域面积分别占比8%和2%.2)近10年建设用地面积显著增加了4倍;耕地面积减少了38%;林草地面积先增加后减少,水域面积总体上呈减少趋势。3)研究期内三峡库区林草地转入最多,主要来自耕地,有7640.13 km^(2)的耕地转化为了林草地;耕地转出最多,除主要转为林草地外,转为建设用地面积最大,为1930.20 km^(2).4)三峡库区土地利用变化的主要原因一方面是城市化和工业化进程的快速推进,另一方面是国家生态文明建设要求尤其是退耕还林、还草相关政策的提出和落实。

Land use change is vital to show the close connection between man and nature,and the change of land use pattern can reflect the strength of human use and transformation of nature and the changing trend of the surrounding environment.Based on the remote sensing images of the Three Gorges Reservoir area in four periods of 2007,2010,2013 and 2019,this paper first extracted the areas of four land use types of cultivated land,forest and grassland,water area and construction land by using ENVI software supervision and classification function and manual visual interpretation method,and then carried out quantitative study to analyze the characteristics of land use change in the Three Gorges Reservoir area from 2007 to 2019 from the speed of land use change and transfer direction,and finally probed into the reasons for the change of land use pattern.The results showed that:1)the Three Gorges Reservoir area was dominated by forest,grassland and cultivated land,which accounted for 76%and 14%of the area in 2019,respectively;Construction land and water area accounted for 8%and 2%respectively.2)The area of construction land has increased significantly by 4 times in the past decade;Arable land area decreased by 38%;The area of forest and grassland first increased and then decreased,and the water area showed a general trend of decreasing.3)During the study period,the most forest and grassland in the Three Gorges Reservoir area was mainly transferred from cultivated land,with 7640.13 km^(2) of which converted into forest and grassland;cultivated land was the land type with the largest area transferred into forest,grassland and construction land with the largest converted area of 1930.20 km^(2).4)the change in land use is mainly attributed to the rapid advancement of urbanization and industrialization as well as the construction of national ecological civilization construction,especially the proposal and implementation of relevant policies for returning farmland to forest and grassland.