Spatial-temporal big data reflects human activity at different scales.
(A) At the national level: Data points depict the fact that most of China’s population is concentrated in large cities in the east. As the brightness of the spot increases, the aggregation of the data points (population) increases. (B) At the regional level: This figure shows urban clusters in the Yangtze River Delta. (C) At the zone level: Zhangjiang Hi-tech Park in Shanghai. (D) At the building level: Pudong Airport in Shanghai. Maps were created using C and Datamaps (https://github.com/ericfischer/datamaps), and the remote sensing images were derived from Baidu Maps.