As of March 9, 2021, Xi is a new first-tier city. The 15 new first-tier cities are: Chengdu, Chongqing, Hangzhou, Wuhan, Xi'an, Tianjin, Suzhou, Nanjing, Zhengzhou, Changsha, Dongguan, Shenyang, Qingdao, Hefei and Foshan. New Tier 1 Cities is CBN New Tier 1 Cities Research Institute's ranking of 337 cities above prefecture level in China based on data from brands, user behavior data from Internet companies, and city big data from data agencies. The criteria for this list are based on five indicators: concentration of business resources, urban hubs, urban population activity, lifestyle diversity and future plasticity. The algorithm framework is as follows: the weights of the first-level indicators are calculated by the Expert Committee of New Tier 1 Cities Research Institute, and the data below the second-level indicators are calculated by Principal Component Analysis.Xi'an's geological structure spans the Qinling Trough Fold Belt and the North China Plateau. About 130 million years ago, a major fault occurred across the northern foot of the Qinling Mountains during the Yanshan Movement. Since the Late Tertiary Period about 3 million years ago, the neotectonic movement in the Qinling Trough Fold Belt to the south of the Great Fault has been unusually active, and the mountain ranges have fallen sharply from north to south, creating the Qinling Mountains. At the same time, north of the Great Fault belonging to the North China Plateau Weihe Fault continued to subside, in the wind into loess cover and Weihe River alluvial **** the same role in the formation of the Weihe Plain. Extended Data:Xi'an is located in the center of China's land map and the junction of China's central and western economic zones, and is the necessary route from the northwest to the cities of the Central Plains, North China and East China. In the national regional economic layout, Xi'an, as the largest western center city along the economic belt of the Longhai-Lanxin Railway, the Chinese section of the New Asia-Europe Continental Bridge, is the bridgehead of the national implementation of the strategy for the development of the western region, and has the important strategic position of carrying the east to the west and connecting the north and the south. Highway construction has formed a Xi'an as the center, nine national highways in this intersection, through Shaanxi Province, radiating the surrounding provinces and cities of the high-grade "m" radial trunk highway system. There are more than 2,800 kilometers of highways and six national trunk highways passing through the city. The city-around highway and the new airport line have been completed, and the second and third ring roads have been fully opened. All urban areas and counties under the jurisdiction of the city have opened the highway.