Urbanization that hides in the dark – Spotting China’s “ghost neighborhoods” from space

Abstract

The excessive planning and construction of new cities and towns as well the massive expansion of planned settlement areas in China reveals a surprising phenomenon: extensive newly constructed areas that are characterized by severe under capacity. This phenomenon is described as “ghost city” and usually appears at the intra-urban scale. However, current data and methods are inappropriate to detect this phenomenon at this intraurban scale for entire China. Besides, most studies neglect the usual immigration period of newly built areas. In this study, we suggest a new term, the “ghost neighborhood”, which refers to a new residential neighborhood that still runs at severe under capacity after a typical immigration period of five to six years. Based on this conceptual baseline, we identify “ghost neighborhoods” across China by developing a methodology to gradually exclude the “non-ghost areas” by predominantly relying on night-light emissions. The process is based on LJ1-01 night-light data, TanDEM-X data and Global Urban Footprint data, which feature evident advantages in spatial resolutions while being available for entire China. The main results are as follows: 1) we identify 1048 “ghost neighborhoods” across the urban landscapes of China with a total coverage area of 353.64 km2; they are estimated to have the capacity to house 13.6 million people; 2) the identified “ghost neighborhoods” are particularly frequent and large in the dynamically urbanizing regions, such as the Pearl River Delta, the Yangtze River Delta and the entire Shandong province.