Shenzhen, referred to as "Shenzhen" for short and also called Pengcheng, is a sub provincial city, a city specifically designated in the state plan, a megacity in Guangdong Province, a special economic zone in China, a national economic center and an international city approved by the State Council [1]. By the end of 2019, the city had nine districts, with a total area of 1997.47 square kilometers, a built-up area of 927.96 square kilometers, and a permanent population of 13.4388 million, an increase of 412,200 over the end of last year. Among them, the permanent registered residence population is 4.9478 million, and the permanent non registered residence population is 8.491 million