Spatio-temporal evolution of urban thermal environment and its driving factors: Case study of Nanjing, China

In recent years, with the rapid urbanization, the urban underlying surface has changed dramatically. Various urban eco-environmental problems have emerged in the world, among which the urban heat island effect has become one of the most obvious urban eco-environmental problems. In this study, Nanjing, China is chosen as the study area. Based on the Landsat8 remote sensing image data in Nanjing from 2014 to 2018, the land surface temperature is retrieved, the spatiotemporal variation track and characteristics of the thermal environment pattern are systematically depicted, and its driving factors are revealed. The results show that: in the past five years, the spatial pattern of heat field in Nanjing has changed from scattered distribution in the periphery of the city to centralized in the center of the city, and the heat island intensity has increased year by year. The changes of administrative divisions, the layout of transportation trunk lines, the transfer of industrial centers, and ecological construction projects are important driving factors for the evolution of land surface thermal environment pattern of these regions. The research results will provide scientific and technological support for similar cities with typical heat island effect in the world to make urban planning and development decisions, and to govern and improve urban ecological environment.