An urban heat island study in Nanchang City, China based on land surface temperature and social-ecological variables

Abstract

This article examines the spatial and temporal patterns of land surface temperature (LST) in Nanchang City, China in the context of the urban heat island (UHI) phenomenon. It also investigates the relationship of LST with six social-ecological variables, namely land use/land cover (LULC), vegetation index, impervious surface index, water index, population density, and fossil-fuel CO2 emission. Landsat data captured in 2000 and 2013 and geographic information systems techniques were used to facilitate the analysis. The results show that the overall mean LST in the study area increased by 1.64°C between 2000 and 2013. This temporal variation in LST might have been influenced by the given environmental conditions at the time when the source satellite images were captured. That said, there have been indications that the detected increase in the overall mean LST has been influenced by the rapid urbanization of the area, resulting in the rapid expansion of impervious surfaces and loss of green spaces. In both time points, the urban LULC class (impervious surfaces) had a consistent high LST and all the other social-ecological variables examined had statistically significant relationships with LST. We recommend that these variables be taken into consideration in the landscape and urban planning process for the future development of the city. This study also emphasizes on the importance of urban green spaces because of their ability to mitigate UHI effects and the valuable ecosystem services they generate for and provide to people. Urban green spaces can help improve the overall livability and environmental sustainability of cities.