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.
Youyi County is located in the western part of Shuangyashan City, Heilongjiang Province, under the jurisdiction of Shuangyashan City. The geographical location is 46 °28 °14 "~ 46 °59 °38" N and 131 °27 °50 "~ 132 °15'E. It is located in the hinterland of Heilongjiang, Songhua River and Wusuli River. It is adjacent to Baoqing County in the east, Shuangyashan City in the south, Jixian County in the west and Fujin City in the north. The terrain in Friendship County is flat and low-lying, with hills in the southwest and lowlands in the northeast, tilting from southwest to northeast. In 2012, Youyi County has a total population of 125000. The total area is 1888 square kilometers. Youyi County has a mid-temperate continental climate, with an average annual temperature of 2.5C, an average annual rainfall of 500mm, an average of 2730 hours of light, and a frost-free period of 120.1.