Colorado Springs is a home rule municipality in, and the county seat of, El Paso County, Colorado, United States. It is the largest city in El Paso County, with a population of 478,961 at the 2020 United States Census, a 15.02% increase since 2010. Colorado Springs is the second-most populous city and the most extensive city in the state of Colorado, and the 40th-most populous city in the United States. It is the principal city of the Colorado Springs metropolitan area and the second-most prominent city of the Front Range Urban Corridor. It is located in east-central Colorado, on Fountain Creek, 70 miles (113 km) south of Denver.
Tongchuan is a municipality under the jurisdiction of Shaanxi Province, which is located in the junction zone of central Shaanxi Province, Guanzhong Basin and Northern Shaanxi Plateau, adjacent to Yan'an, Weinan and Xianyang. Tongchuan is a continental monsoon climate with four distinct seasons and obvious monthly changes in air temperature. the area is 3882 square kilometers, and the city has jurisdiction over three districts and one county. In 2017, the city's resident population was 833400. Tongchuan has convenient transportation, which is an important part of the Guanzhong economic belt, and it is a necessary place leading to the Mausoleum of the Yellow Emperor and Yan'an, the holy place of revolution. Tongchuan New area is 68 kilometers away from Xi'an and 72 kilometers away from Xi'an Xianyang International Airport. Xi'an-Huangling Expressway passes through the border, and the two branch railways of Xiantong and Meiqi are connected with the Longhai artery. In 2017, Tongchuan achieved a GDP of 34.859 billion yuan, of which the added value of the primary industry