Spatial pattern of thermal and ecological environment in Shanghai

Abstract

Shanghai has experienced rapid urbanization over the past three decades. With the rapid development and expansion of city, the physical characteristics (such as land cover types, surface albedo and so on) and property of the urban underlying surface are undergoing substantially changes, which significantly impact the climate and ecological environment. Based on the Landsat TM remote sensing imagery, with the remote sensing (RS) and geographic information system (GIS) spatial analysis techniques, spatial pattern of land surface temperature (LST), land use type, vegetation coverage, surface albedo and the relationship between LST and vegetation was analyzed in this study. The results indicate that LST in urban and suburban areas is higher than that in exurban areas of Shanghai. The dominant land use type in urban areas is residential land, but in exurban areas, farmland is the main land use type. From urban to exurban areas, the vegetation coverage and surface albedo increase gradually. In urban, suburban and exurban areas, the mean vegetation coverage is 0.01, 0.078 and 0.126 respectively, and the mean surface albedo is 0.067, 0.083 and 0.189 respectively. The distribution of LST is well corresponding with the land use types in Shanghai, with residential areas and buildings have higher LST. LST possesses a negative correlation with the vegetation coverage and normalized difference vegetation index (NDVI) for all land cover types, and in the urban areas, the low vegetation coverage is the important contributor of the higher LST. The change in urban albedo has significant impact on the evolution of LST.