Landscape pattern changes in urbanization of Pudong New District,Shanghai
利用1994和2000年航空遥感影像资料解译的土地利用与覆盖数据,在GIS支持下,采用景观格局指数和梯度方法分析了上海市浦东新区城市化过程中景观格局的变化.结果表明,随着城市化程度的推进,浦东新区由原来以农业为主的格局逐渐转变成以居民地、公共设施和工厂为主的城市景观格局,农田占地比例由1994年的71.45%下降到2000年的41.32%,居民地、公共设施和工厂总占地由1994年的18.2%上升到2000年的41.9%.整体景观格局的破碎化程度和异质性都有所增加,斑块个数由1994年的4.08个·km-2上升至2000年28.65个·km-2,面积平均加权由24.43 km2减少到1.75 km2,聚集度由98.31下降为95.09,多样性和均匀性指数分别由0.4697和0.5284增至0.7509和0.8343.在样带梯度分析中,景观格局指数能检测出城市化梯度及城市化程度不断向郊区递减的趋势,城市化水平较高地区以人工景观为主,表现出斑块个数多且面积小、斑块形状简单和景观多样性高等景观特征.景观格局动态变化分析是了解城市化过程中城市形态、结构及生态过程的基础.
Urbanization is one of the most important anthropogenic impacts on natural
landscape,while urban landscape pattern can reflect the urbanization process and its ecological consequences.In this paper,landscape metrics combined with gradient analysis was employed to analyze the landscape pattern changes of Pudong New District in Shanghai,based on the land use datasets derived from 1∶50 000 aerial photos of 1994 and 2000, respectively. The results demonstrated that the landscape pattern of Pudong changed dramatically in its ever-increasing urbanization.The land cover,which was dominated by agriculture in 1994,gradually transformed to urban land use,such as residential area,public facilities,and industry.The percentage of agriculture land use decreased from 71.45% to 41.32%,while the urban land use hold 18.2% in 1994 but rose to 41.9% in 2000.Synoptic landscape characteristics showed the increased patch numbers (from 4.08 to 28.65 ind.·km-2),diminished areaweighted mean (from 24.43 to 1.75 km2),decreased aggregation index (from 98.31 to 95.09),and augmented landscape diversity and evenness,all of which demonstrated the higher landscape fragmentation and landscape heterogeneity induced by urbanization.The landscape pattern along the urbanrural gradient reflected the different urbanization stages,and the expanding urban frontier in different years in Pudong New District could be identified precisely with class-level landscape indices.The changes in landscape pattern along the transect suggested that the quantitative analysis of landscape dynamics,especially the landscape metrics combined with gradient analysis,could be a robust tool to study urban morphology,urban structure,and ecological consequences during urbanization.
全 文 :