Funding for this research was provided by:
National Natural Science Foundation of China (41771441, 41901391)
Beijing Key Laboratory of Urban Spatial Information Engineering (2020207)
Shenzhen Basic Research Program (JCYJ20190807163001783)
Natural Science Foundation of Guangdong Province, China (2021)
Received: 5 October 2020
Accepted: 10 March 2021
First Online: 25 March 2021
: Not applicable.
: Agreement for publication.
: The authors declare no competing interests.