Monitoring the Spatiotemporal Dynamics of Urban Green Space and Its Impacts on Thermal Environment in Shenzhen City from 1978 to 2018 with Remote Sensing Data

In a developing city, urban green space (UGS) plays an increasingly significant role in improving the urban environment and beautifying the urban landscape. In the meantime, UGS has been substantially and frequently interfered with by human activities. Taking Shenzhen city (a great metropolis of China) as an example, this study investigated the spatio-temporal dynamics of UGS and its influence on the urban thermal environment with Landsat images. From 1978 to 2018, all croplands and more than 50% of water bodies disappeared, while the built-up area increased more than 6 times. The rapid expansion of impervious surface and loss of UGS led to the spread of a surface urban heat island. The study shows that UGS has a significantly mitigating impact on urban land surface temperature, with cold islands mainly located at city parks. The results will be of great significance for improving UGS management, alleviating the urban heat island effect, and establishing a sustainable eco-environment.