Trapped in Shu, why can Han Xin sneak into Chencang and Zhuge Liang can only leave Qishan?

Later, Zhuge Liang tried to cross Chencang Road in the second Northern Expedition, but a thousand people could not defeat them, so he had to retreat. Later, he walked through Qishan Road. Anyway, all methods have been used up. Except the most dangerous meridians and collaterals, other methods have been used, but the final effect is not ideal.

As I said before, Han Xin took the main force out of Chencang because he could transport soldiers and food by water, because there is a Tianchi osawa with huge water storage capacity to connect Hanshui River with Jialing River. At the same time, Ozawa Tianchi also plays a role in regulating the river flow rate, making the flow rate of Hanshui River and Jialing River gentle. So he can use ships on a large scale when he sends troops.

There is a big difference between sea transportation and land transportation. This ship has a large cargo capacity and a high speed. More importantly, they consume less. Ships in the Qin and Han Dynasties could carry 50 people and food for three months.

Zhuge Liang was sure to win several northern expeditions later, but he had no choice but to withdraw. The reason is that "food is in full view". In order to solve the problem of transporting grain, Zhuge Liang later invented a series of activities, such as "wooden oxen flowing horses", and carried out a series of activities on the border of Cao and Wei, but he could do nothing, because he had lost the conditions of water transportation and could only rely on manpower for land transportation, because Tianchi osawa had disappeared at that time.

In 186 BC, that is, the tenth year after Liu Bang's death, a major earthquake occurred in Ningqiang area of Lueyang City, Shaanxi Province, which had an extremely extensive impact, leading to a large-scale landslide in the mountainous area of Hanwang Mountain and even blocking the Hanshui River. These accumulated rocks form a huge dammed lake natural dam in the upper reaches of the Hanshui River, which divides the Hanshui River into the Western Han River and the Hanshui River.

Liu Bei, Zhuge Liang and others gathered together to learn from Liu Bang and revive their heroic spirit. However, although they were also trapped in Shu, the environment they faced was completely different, so Han Xin could calmly "build a plank road and hide a warehouse", but without Zhuge Liang's water, they were firmly sealed between the mountains.