Ya 'an, also known as Yucheng, is a prefecture-level city in Sichuan Province, located at the western edge of Sichuan Basin, at the foot of Qionglai Mountain, adjacent to Chengdu in the east, Ganzi Tibetan Autonomous Prefecture in the west, Liangshan Yi Autonomous Prefecture in the south and Aba Tibetan and Qiang Autonomous Prefecture in the north. It belongs to the mountainous area on the western edge of Sichuan Basin, spanning the two topographic areas of Sichuan Basin and Qinghai-Tibet Plateau, and belongs to subtropical monsoon humid climate, with a total area of 15046 square kilometers.
In the 24th year of the Republic of China (1935), Ya 'an County was established. Ya 'an is located at the intersection of Sichuan-Tibet and Sichuan-Yunnan highways, 20 kilometers away from Chengdu/KLOC-0. It is a transitional zone between Sichuan Basin and Qinghai-Tibet Plateau, between Chinese culture and national culture, between modern central cities and primitive natural ecological areas. It was the gateway and the only way to the ancient Southern Silk Road, and was once the capital of Xikang Province.
topography
Ya 'an City belongs to the mountainous area on the western edge of Sichuan Basin, which straddles the Sichuan Basin and the Qinghai-Tibet Plateau. It is a transitional zone from the basin to the Qinghai-Tibet Plateau. The terrain is high in the north, west and south and low in the middle and east. The highest point is Fairy Liangzi at the junction of Asbestos, Kangding and Jiulong counties in the southwest, with the main peak at an altitude of 5,793 meters and the lowest point at the exit of Qingyi River in Caoba, with an altitude of 5 15.97 meters.
Hilly flat dams are mostly distributed on both sides of the valley, accounting for only 6% of the city's area. The low mountains are located in Yucheng District and the famous counties in the middle, accounting for 4% of the city's area. Zhongshan is the most widely distributed, accounting for more than 60% of the total land, and high mountains account for 6% of the total area of the city. Most of them are distributed in Baoxing County, the northwest of tianquan county, the southwest of Shimian County and the northern end of Lushan County, with a relative height difference of 100 ~ 2000.
Reference to the above content: Baidu Encyclopedia-Ya 'an