Discrepant impacts of land use and land cover on urban heat islands: A case study of Shanghai, China

The most visible aspect of urbanization is that more and more natural landscape is replaced by anthropogenic land cover/land use, which is the driving force of many ecological and environmental consequences such as urban heat islands. However, the difference between land use and land cover and their implications in ecology is often overlooked. The impacts of urban land cover composition and configuration on land surface temperature (LST) have been extensively investigated, but few studies have explored the relation between LST and land use category. This research takes the inner city of Shanghai as a case and comprehensively investigates the discrepant impacts of land use and land cover on LST. Land use and land cover data are derived respectively from aerial photography and high-resolution satellite imagery (ALOS), and the LST is estimated from Landsat TM images. There are five dominant land use types (new residential, old residential, villas, industrial, and institutional land use) and two major land cover types (vegetated and impervious land cover) in the study area. For most land use types, the land cover composition and configuration are varied. By contrast, no statistical difference is observed among old residential, industrial and institutional land uses for LST. The mean LST of new residential and industrial land use is significantly different, although their land cover compositions and configurations are quite similar. These results indicate that the key factors affecting urban LST are not only land cover patterns, but also other anthropogenic forces. Therefore, the explanation of urban LST by land cover alone is inadequate. Especially at fine spatial scales, information on land use is more meaningful than that of land cover to indicate the impacts of urbanization on ecosystems.