The changes in population and topography of Yan'an from ancient times to the present

Archaeological findings show that about 30,000 years ago, late Homo sapiens "Huanglong Man" lived in Yan'an. Around the 13th century BC, Yan'an belonged to the independent territory of Fang State and Guifang State. Shang Emperor Wu Ding once launched a large-scale war against the ghosts. "Book of Changes Jiji" records: "Gaozong attacked Guifang and defeated it in three years." This is the earliest written record of Yan'an that is known so far. During the Spring and Autumn Period, Yan'an was home to the Baidi tribe, a minority nomadic and hunting tribe. Chong'er, the prince of Jin Dynasty, lived in exile in Baidi for 12 years and lived in Yan'an area. During the Warring States Period, most of Yan'an belonged to the State of Wei. "Historical Records of the Qin Dynasty" records: "Wei built the Great Wall, and there is Shangjun north of Zheng Binluo." In the seventh year of King Huiwen of Qin (300 BC), Qin Commander Gongsun Yan defeated the Wei army at Diaoyin (today's Sigou River, Ganquan County, Shaanxi Province), beheaded more than 80,000 people, and captured Wei General Long Jia; in the eighth year of King Huiwen of Qin, Wei Na Hexi To Qin; in ten years, 15 counties of Wei Na Shangjun (now Yichuan and Yan'an in northern Shaanxi) were given to Qin. Yan'an originally belonged to Qin.

During the Qin and Han Dynasties, Yan'an belonged to Shangjun (the county governed Fushi, south of today's Yulin City). During the period of King Zhao of Qin, Qin established Gaonu County in the Yan'an area, and the county seat was located in Yinjiagou, east of today's Yan'an City. This was the beginning of Yan'an's city building, and its walls still exist today. After Qin unified the six kingdoms, General Meng Tian led 300,000 troops to attack the Xiongnu from the north, and later supervised the construction of the Great Wall and the Qin Straight Road. During the reign of Emperor Wu of the Han Dynasty, there were a large number of immigrants and garrison camps, which led to unprecedented agricultural economic development in northern Shaanxi and other places, and was known as "New Qinzhong" (meaning as prosperous as Guanzhong). Yu Xu of the Han Dynasty described it in "Zou Fu San Jun Shu", "The water and grass are abundant, and the land is suitable for grazing, with cattle and horses tied to their tails, and sheep blocking the roads."

Yan'an is located in the middle reaches of the Yellow River and belongs to the hilly and ravine area of ??the Loess Plateau. Yan'an's landform is dominated by loess plateaus and hills. The terrain is high in the northwest and low in the southeast, with an average altitude of about 1,200 meters. Baiyu Mountain in the north has an altitude of 1,600 to 1,800 meters. The highest point is at the top of Baiyu Mountain in Wugucheng Township, Wuqi County, with an altitude of 1,809.8 meters; the lowest point is at Houerchuan, Jiyi Township, Yichuan County, with an altitude of 388.8 meters, with a relative height difference of 1,421 meters. . The northern part is dominated by loess hills and ravines, accounting for 72% of the total area of ??the region; the southern part is dominated by loess plateaus and ravines, accounting for 19% of the total area; and the stony mountains of the region account for 9% of the total area. Ziwu Ridge in the west, running north-south, forms the watershed between the Luohe River and the Jinghe River. It is one of the bedrock mountains higher than the Loess Plateau, with an altitude of 1,500 to 1,600 meters, and the main peak is 1,687 meters; Huanglong Mountain in the east, extending roughly in a north-south direction, with an altitude of 1,500 meters meters, the main peak (Daling) is 1788.7 meters above sea level; the central Laoshan Mountain runs northwest-southeast with an average altitude of 1400 meters, and the main peak (Dadunliang) is 1464 meters above sea level. Huanglong Mountain and Laoshan Mountain are collectively known as the Liangshan Mountains and form the skeleton of the Yan'an region's terrain.