Nanning, referred to as "Tancheng" for short, also known as Greentown and Tancheng, is a prefecture-level city, provincial capital and core city of Beibu Gulf urban agglomeration under the jurisdiction of Guangxi Zhuang Autonomous Region, a central city of Beibu Gulf Economic Zone approved by the State Council, and a comprehensive transportation hub connecting the southwest to the sea [1]. By 2020, there will be 7 districts and 4 counties 1 county-level city [2], with a total area of 22 1 10,000 square kilometers [99] and a permanent population of 874 1.584[98]. In 20021year, the city's GDP reached 51209.4 billion yuan, an increase of 6. 1% over the previous year at constant prices.