San Diego (/ˌsæn diˈeɪɡoʊ/ SAN dee-AY-goh, Spanish: [san ˈdjeɣo]; Spanish for 'Saint Didacus') is a city on the Pacific Ocean coast of Southern California located immediately adjacent to the Mexico–United States border. With a 2020 population of 1,386,932, it is the eighth most populous city in the United States and the seat of San Diego County, the fifth most populous county in the United States, with 3,338,330 estimated residents as of 2019. The city is known for its mild year-round climate, natural deep-water harbor, extensive beaches and parks, long association with the United States Navy, and recent emergence as a healthcare and biotechnology development center. San Diego is the second largest city in the state of California, after Los Angeles.
Yongchang County, which belongs to Jinchang City, Gansu Province, is located in the northwest of Gansu Province, in the east of Hexi Corridor, the northern foot of Qilian Mountain and the southern edge of Alashan platform. It is bordered by Wuwei to the east, Jinchuan to the north, Shandan to the west and Sunan to the south. The geographical coordinates are 101 °04 east longitude 102 °43 mi, 37 °47 mi 38 °39'N. The longest distance from east to west is 144.8 km, and the widest distance from north to south is 144.55 km, with a total area of 7439.27 square kilometers. As of 2014, Yongchang County has jurisdiction over 6 towns and 4 townships, with a total of 111administrative villages, 917 village groups and 10 communities, with a total population of 235300 (by the end of 2017), mainly Han nationality, and ethnic minorities such as Mongolian, Hui and Pan. In 2017, Yongchang County realized the regional gross domestic product.