Phoenix (/ˈfiːnɪks/ FEE-niks; Navajo: Hoozdo; Spanish: Fénix or Fínix,[citation needed] Walapai: Banyà:nyuwá) is the capital and most populous city of the U.S. state
of Arizona, with 1,608,139 residents as of 2020. It is the fifth-most populous city in the United States, and the only U.S. state capital with a population of more than one million residents.
Phoenix is the anchor of the Phoenix metropolitan area, also known as the Valley of the Sun, which in turn is part of the Salt River Valley. The metropolitan area is the 11th largest by population in the United States, with approximately 4.85 million people as of 2020. Phoenix, the seat of Maricopa County, has the largest area of all cities in Arizona, with an area of 517.9 square miles (1,341 km2), and is also the 11th largest city by area in the United States. It is the largest metropolitan area, both by population and size, of the Arizona Sun Corridor megaregion.
Zhouqu County, which belongs to Gannan Tibetan Autonomous Prefecture in Gansu Province, is located in the south of Gansu Province and in the southeast of Gannan Tibetan Autonomous Prefecture. Zhouqu means "Longjiang" in Tibetan and gets its name from the Bailong River passing through the county. Zhouqu system began in the pre-Qin period. In the 28th year of Qin Zhaowang (279 BC), Qiangdao County was located in the northwest of Zhouqu, Xigu County was set up after liberation, Zhouqu County was renamed Longdi County in 1959, and Zhouqu County was restored in 1962. By 2016, Zhouqu County had jurisdiction over 4 towns, 15 townships, 208 administrative villages and 403 natural villages, with a total population of 142000, of which 50400 were Tibetans, accounting for 35.8%. Zhouqu County is located in the Min, Dieshan system of the West Qinling Mountains and the edge of the Qinghai-Tibet Plateau, which is a typical alpine canyon landform. "one river and two rivers (Bailong River and Gongba River)