长三角城市群城市扩张区环境质量变化遥感评价

Remote Sensing Analysis of Environmental Change in Urban Expansion area of Yangtze River Delta Urban Agglomeration

加强城市动态扩张与环境质量变化监测对促进长三角城市群高质量一体化协同发展具有重要意义。基于DMSP/OLS夜间灯光数据、多源环境遥感数据等,运用趋势线分析、综合评价指数(Comprehensive Evaluation Index,CEI)构建等方法,对长三角城市群2001~2013年的城市扩张模式、扩张区内环境质量变化特征及二者的协调性情况进行分析。结果表明:①46.24%的城市显著扩张,上海—苏锡常城市化水平和一体化程度最高,其次为环杭州湾城市群和沿江发展带,此外未形成多区域规模化的城市高速扩张模式,经济总量、对外开放程度和用电水平是长三角城市高速扩张的主要驱动因素;②46.35%的显著扩张区环境逐步恶化,集中在江苏省和安徽省,环境恶化型集聚在合肥主城区周围,浙江省城市环境最优,上海市基本未变,多数城市环境变化主要由PM2.5增长所致;③城市扩张与环境变化叠加结果可反映区域城市发展与生态环境建设的协调程度。上海市嘉定区、浦东新区和崇明岛,苏锡常及沿江地区协调性较弱,浙江省城市的“渐变”分布模式体现其高协调性,合肥市城区表现为环境质量远落后于城市化进程的双系统非协调发展状态。谷歌影像定位结果表明结合DMSP/OLS与CEI可有效检测出区域内由人类活动所产生的环境破坏型地表覆盖类型变化情况。该研究成果可揭示区域可持续发展状况,对长三角双系统动态发展协调性的空间转移研究具有指示作用。

Monitoring urban expansion and environmental change is significant to promote high-quality integrat⁃ed development in Yangtze River Delta urban agglomeration(YRD).Based on DMSP/OLS night-time light data,multi-source remote sensing environmental indicators,methods of slope trend line analysis,construction of Comprehensive Evaluation Index(CEI)were used to analyze the characteristics of urban expansion,environ⁃mental change and their coordination of YRD from 2001 to 2013.The results showed that:(1)46.24%of the cities expanded significantly,with the highest level of urbanization and urban integrated development in the re⁃gion of Shanghai-Suzhou-Wuxi-Changzhou,followed by the Hangzhou Bay urban agglomeration and the re⁃gions along the Yangtze River.However,the high-speed urban expansion mode was not multi-regional and large-scale in YRD.GDP,the degree of opening to the outside world and electricity consumption were the main driving factors for the high-speed urban expansion.(2)In 46.35%of the significant urban expansion area,the environment gradually degraded,which was concentrated in Jiangsu and Anhui Province.Environment-deg⁃radation type was clustered around the downtown of Hefei.Environment quality of Zhejiang Province was the best,while that of Shanghai was almost unchanged.PM2.5 growth was an important reason for environmental change in most cities.(3)The superposition of urban expansion and environmental change can reflect the coordi⁃nation degree of urban development and ecological environmental change.The coordination in Jiading District,Pudong New Area and Chongming Island in Shanghai,Suzhou-Wuxi-Changzhou and cities along Yangtze Riv⁃er was weak.The"gradual"distribution pattern in Zhejiang Province cities reflected high coordination,while that in Hefei city reflected a non-coordination mode that the environmental quality was far behind urbanization process.The results of high-resolution satellite images positioning showed that the combination of DMSP/OLS and CEI can successfully monitor the surface cover and its transfer that cause serious environment damage in the process of urbanization.This work can reveal the status of regional sustainable development,and has an instruc⁃tive role in the future study of spatial transfer of dynamic development coordination between urbanization and en⁃vironmental quality in the Yangtze River Delta.