2009—2017年北京市土地利用变化时空特征

Temporal and Spatial Characteristics of Land Use Change in Beijing from 2009 to 2017

对北京市土地利用类型、城市扩张程度和植被覆盖度进行时空特征分析,为合理制定城市空间规划和土地利用管理提供科学依据。以北京市全域为研究对象,基于2009、2013和2017年Landsat遥感影像基础,利用非监督分类方法得到土地类型图,计算城市扩张指数和植被覆盖度指数,并进行环路地类动态变化分析。结果表明:(1)2009—2017年北京市绿地/耕地面积减少746.22 km^(2),建筑用地面积增加601.36 km^(2),两者面积变化表现出此消彼长的趋势;(2)绿地/耕地及建筑用地的空间消长特点存在明显的环路差异;(3)高植被覆盖度区域面积剧烈减少;(4)土地利用类型和植被覆盖度变化在2009—2013年和2009—2017年两阶段内差异明显。可见北京市城市扩张速度有所减缓,绿地/耕地面积相对减少率高,城市土地利用变化存在明显的时空差异。

The spatio-temporal characteristics of land use types,urban expansion and vegetation coverage in Beijing are analyzed to provide a scientific basis for urban planning and land use management.Taking the whole urban area of Beijing as the research area,based on Landsat remote sensing images in 2009,2013 and 2017,land use type maps are obtained using the unsupervised classification method,urban expansion index and the vegetation coverage index are calculated,and dynamic changes of land types in the Ring Roads are analyzed.The results show that:(1)From 2009 to 2017,the area of green/cultivated land decreased by 746.22 km^(2)and construction land increased by 601.36 km^(2),which shows a trend of declining and increasing on area changes;(2)The spatial growth and decline of green/cultivated land and construction land have obvious differences of ring roads;(3)The area of high vegetation coverage decreased drastically;(4)The change of land use type and vegetation coverage is obviously different in the two stages of 2009-2013 and 2009-2017.It can be seen that the speed of urban expansion in Beijing has slowed down,the relative reduction rate of green/cultivated land area is high,and there are obvious spatio-temporal differences in urban land use change.The urban expansion rate has slowed down,the relative reduction rate of green land/arable land area remains high in Beijing,and there are obvious spatial-temporal differences in the urban land use changes.