Predicting effect of forthcoming population growth-induced impervious surface increase on regional thermal environment: Xiong'an New Area, North China

The Xiong'an New Area is a state-level new area to be established in the Baoding area of Hebei province, North China. The planning population growth goal for the area is going to reach 2.5 million and the area is planned to expand to 2000 km2. The potential population growth and area expansion will result in massive increase in impervious surface (IS) dominated built land and thus may impact the area's thermal environment. Therefore, based on current land cover types and thermal environment status in the area, this study developed a statistical model to predict thermal effects responding to the forthcoming population and associated IS increase in the new area using remote sensing technology. This was achieved by relating population growth to IS area increase, exploring the relationships among population, land cover, and land surface temperature (LST), and developing a metric for estimating a balance amount of total IS area to be expanded. The prediction shows that IS has a noteworthy effect on regional thermal environment. The variation in the proportions of the IS in the new area can result in a significant shift of LST. A balance amount of total IS area in the 2000 km2 new area is 433 km2. Exceeding/reducing the amount would result in a rise/decline of the area's LST. Introducing a quantity of IS area-related population density (IPD) reveals that the area's LST is closely related to IPD when the total area and future population of the new area are given.