Fourth-tier cities are mostly medium-sized cities, with relatively average city size, economic and social development level and traffic construction. Most of the fourth-tier cities are prefecture-level cities, including provincial capitals, capitals and autonomous prefectures.
Deyang, also known as "Beijing", is a prefecture-level city under the jurisdiction of Sichuan Province, located in the northeast of Chengdu Plain, the transition zone from Longmen Mountain to Sichuan Basin. The northwest is a mountainous vertical climate, and the southeast is a subtropical humid monsoon climate. The total area of the city is 59 1 1 square kilometer.