上海市城市热岛景观格局演变特征研究

城市热岛空间格局特征及其内在驱动机制的研究可为缓解城市热岛效应、城市规划与产业布局提供科学依据,目前这方面研究还比较少,相关机制并没有得到完全的揭示。该研究以上海市为研究对象,采用1987、1996、2002和2010年4景Landsat TM/ETM+遥感影像,对城市地表温度进行了反演与分级。借助景观格局指数,分析了上海市城市热岛景观格局时空演变特征。结果表明:随着1987-2010年上海市不断城市化,各级热岛景观类型斑块数量持续增加,高等级的城市热岛景观类型面积也持续增加,整个城市热岛景观趋于破碎化。热岛景观总体聚集度下降,连通性下降,但是低等级热岛景观向高等级热岛景观转移的面积逐渐增加,景观类型之间面积差异逐渐减小,景观均匀度和多样性增加。城市化过程中,人口数量的增加和经济的快速发展对城市热岛景观格局的形成和演变具有重要的影响。研究结果揭示了城市热岛格局随城市化进程的时空演变特征,可以为制定有效的热岛效应缓解措施提供参考依据。

Spatial and Temporal Changes of Urban Thermal Landscape Pattern in Shanghai

Spatial patterns of urban heat island and its inherent drive mechanism could provide a scientific basis to ease the urban heat island effect,urban planning and industrial layout,however current research in this area is still relatively scarce and related mechanism has not been fully revealed.By using Landsat Thematic Mapper(TM) and Enhanced Thematic Mapper Plus(ETM +) thermal images of 1987,1996,2002 and 2010,urban surface temperature was inverted and classified in Shanghai.With the help of landscape pattern indices,temporal and spatial landscape pattern variations of urban heat island in Shanghai were analyzed.Results showed that the number of patches in 1987-2010 in Shanghai at all levels continued to increase,high grade area of urban heat island landscape types have continued to grow,and urban heat island landscape tended to fragmentation.Overall heat island landscape aggregation and connectivity declined,while the transfer of low grade heat island landscape to landscape of high grade heat island area gradually increased.Landscape evenness and diversity increased.Population increasing and rapid economic development play an important role for formation and evolution of urban heat island landscape pattern.Results of the study reveal the temporal and spatial pattern of urban heat island with urbanization process,which can provide a reference for development of effective heat island mitigation measures.