Why are Yinshan and Gobi called the natural dividing line between the north and the south of the desert?

First, Yinshan and Gobi: the natural dividing line between the north and the south of the desert.

Yinshan Mountain is geographically one of the dividing lines between monsoon climate zone and continental climate zone. The northern foot of Yinshan Mountain is a vast Gobi desert because of less precipitation, cold climate and relatively bad ecology.

In Yin Shan Zhinan, the Yellow River passes through here, forming the Hetao Plain thousands of miles away, so the Hetao Plain is suitable for agricultural development. It is precisely because of the special geographical environment of Yinshan Mountain that it has become an important area for ancient nomadic and agricultural peoples to compete for.

When nomads crossed Yinshan Mountain and occupied Hetao Plain, the whole Guanzhong area was exposed to the fighters outside the Great Wall. The Central Plains Dynasty occupied the Hetao Plain, and it could compete with the grassland people according to the natural barrier of Yinshan Mountain. From the Warring States to the Qin and Han Dynasties, the Central Plains Dynasty and Xiongnu fought for the Hetao area many times. During the Warring States Period, King Wuling of Zhao established cavalry, captured the Hetao Plain, and emigrated, settled fields and built the Great Wall in the Hetao area.

At the end of the Warring States period, the Huns were powerful and seized the Hetao area in the war in the Central Plains. After Qin's reunification, Qin Shihuang sent Meng Tian to attack Xiongnu in the north, recover the "land of Henan", build the Great Wall and emigrate to the border. At the end of Qin dynasty, Xiongnu occupied this place again and continued to invade. It was not until the period of Emperor Wu of the Han Dynasty that the Hetao Plain was recovered and Shuofang County was established.

It can be seen that the composition of Yinshan Mountain and Gobi Desert is a barrier between nature and humanity. In the Han Dynasty, people called the south of the Gobi Desert "Monan" and the north of the Gobi Desert "Mobei".

Emperor Wu of the Han Dynasty 124 launched the Battle of Monan to recover Monan, and 1 19 launched the Battle of Mobei to destroy the main force of Xiongnu. Since then, many tribes of the Huns began to surrender to the Han Dynasty, which placed most of them in desert areas to help the Han Dynasty defend the frontier.

In the first 60 years, Xiongnu was divided into two parts: South Xiongnu and North Xiongnu. The two Xiongnu are bounded by Gobi and Yinshan, the southern Xiongnu is attached to the Han Dynasty, and the northern Xiongnu is the enemy of the Han Dynasty. After the northern Xiongnu moved westward, the southern Xiongnu moved to Mobei, and was divided into two parts in 48 years. The Southern Xiongnu built a court in Wuyuan (Baotou), which belonged to the Eastern Han Dynasty and guarded the frontier for the Eastern Han Dynasty. The southern Xiongnu moved to Hetao area, and moved to the Central Plains during the Sixteen Countries Period in Wuhu, where they merged with the Han nationality.