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.
Banma County is located in the southeast of the state border, bordering Sichuan Province in the east and south. The county government is located in Moba Township, 315 kilometers away from the state capital. The population is 27000 (2007), mainly Tibetans, accounting for more than 95% of the total population, as well as Han, Hui, Turkish and other ethnic groups. It covers an area of 6376 square kilometers and has jurisdiction over 8 townships and 1 town. The annual average temperature in Banma County is-1.0-2.8 ℃. With the increase of altitude, the temperature decreases gradually. In terms of the annual change of air temperature in Banma County, the monthly average temperature is the highest in July, and the monthly average temperature is 11 ℃. In January, the monthly average temperature is-9.8 ℃, but it is characterized by rapid warming and rapid cooling, and the cooling range is greater than the warming range. Banma County has a total land area of 6138 square kilometers, accounting for 8.03% of the total area of the state. The grassland area is 396700 hectares.