快速城市化背景下上海绿色空间时空动态演变

从"绿色空间"这一城市可持续发展中社会、经济与生态统筹的切入点入手,基于遥感影像数据,从土地利用类型的角度,通过对上海城市绿色空间结构和演变过程的追踪,对1997、2000、2005和2008年绿色空间时空变化特征进行了深入分析。结果表明,研究区总体上以绿色空间的减少和非绿色空间的增加为典型特征。11年间,在各种绿色空间用地变化中,农田动态变化度最高,面积变化最大,共减少了661.50 km~2,减幅达22.69%;从农田的转移方向来看,主要是转变为建设用地和城镇绿地,分别占农田面积总流出量的72.14%和37.37%;而森林绿地、灌草地和水域的总面积基本保持稳定,但其动态变化度均有不同程度变化,表明内部结构不稳定性增强,绿色空间内部类型的转变主要是农田向城市绿地转变。从景观多样性时空演变分析看,郊区地区比中心城区有着更高景观多样性。

The spatio-temporal dynamics of the green space and landscape in rapidly urbanizing Shanghai

Rapid urbanization has caused a series of eco-environmental problems associated with the change of green space.A common consensus has been achieved that green spaces are valuable resources in coupled natural and human urban systems.As the most rapidly urbanizing area in China,Shanghai's landscape patterns experienced a tremendous change.Through the integrated approach of remote sensing and geographic information system (GIS) techniques,four Landsat TM/ETM+ imagery acquired from 1997 to 2008 were used to quantitatively characterize the patterns of urban green space change in the fast-growing Shanghai Metropolis.Results showed that the cropland decreased 661.50 km2 with a drop of 22.69％.The area of forest,shrub and water were kept in balance whereas the spatial dynamics changed dramatically in the study area.As a result,during 1997 and 2008,approximately 72.14％ of the cropland was converted to urban/construction land and 37.37％ to urban green space.The spatial distributions of the landscape diversity identified the areas where the landscape diversity significantly changed in the metropolitan area of Shanghai.The spatiotemporal pattern of the landscape diversity in the suburban area was higher than the central area of Shanhai.