长江三角洲地区城镇时空动态格局及其环境效应

利用多期遥感影像对长江三角洲地区城镇近15年来的时空变化特征进行了分析,揭示了地区城镇化的空间格局与其生态环境的相互关系。结果表明:80年代中后期至2000年之间以农业景观为主的农田、林地显著减少,城镇迅速扩张,呈集中化趋势。前后五年的土地利用动态变化的构成比例不同,后期城市扩展的速度明显减慢。土地利用的动态变化引起了环境的一系列变化,其扩展方式直接影响到局地气候及区域空气质量。

Analysis of the relationship between urban dynamic change pattern of the Yangtze River Delta and the regional eco-environment

After the adoption of the policy of reform and opening-up to the outside world, many changes in politics, society and economy have taken place in the Yangtze River Delta region and have resulted in rapid expansion of urban area. Using multi-temporal remote sensing images, we analysed the spatial and temporal urban dynamic change pattern of the Yangtze River Delta region in the past two decades. The results showed that from the end of the 1980s to the year 2000, the main land use change pattern is the rapid decrease of cultivable land and forest area and the fast expansion of urban area. Urban land use in the Yangtze River Delta presents a concentrated expansion, typically from vegetation landscape to a mixed urban and rural landscape, i. e , 95% from farmland 1.8% from forest land and 1.5% from grassland. Using remote sensing image to categorize land use, monitor land use change, and calculate land use change transfer matrix is a promising method to show distributed spatial pattern of land use and land use dynamic change. There exist different constitutional proportions relating to land use dynamic changes between the first decade and the second decade. The urban sprawl speed is lower in the second decade than the first one. The land use dynamic change affects the eco-environmental change in this region. For example, the urban expansion pattern directly affects the local climate change and the air quality of this region. Analyzing the correlation between the spatial pattern of urbanization and eco-environment in this region, we found that the urban sprawl pattern is one of the direct factors affecting the spatial distribution of regional urban heat islands and spatial pervasion of urban air poilution. By comparing the relationship between the land use change pattern and eco-environment, we can provide sustained decision-making strategy for improving eco-environment, developing local economy, and promoting the social progress.