On the north bank of the Jing River in the northwest of Jingyang County, Shaanxi Province, there is one of the earliest large-scale water conservancy projects in Guanzhong, which diverts water from the west to the east and injects luoshui in the east, with a total length of more than 300 miles and an irrigation area of more than 40,000 hectares, which is the famous Zhengguo Canal.
From the Qin Dynasty to the Qing Dynasty for more than two thousand years, Guanzhong has always been regarded as the granary of the world, but before that, this area only watched the ordinary plains of the heavens eat, and even there would be a situation of grain harvest failure.
In the event of this change, Zheng Guoqu's contribution is crucial, and its designer Zheng Guo is even more legendary.
At the end of the Warring States period, the State of Qin was already the most powerful of the Seven Heroes of the Warring States, with a land area comparable to that of the State of Chu, a military capability stronger than that of the State of Zhao, and an economic strength comparable to that of the State of Qi.
Especially after the Battle of Changping, the world formed a pattern of one super and six weak, and the general trend of the Qin state destroying the six kingdoms has been formed.
From the geographical point of view, Korea is not only a close neighbor of the Qin State, but also controls the Kunhan Passage, which is the only way for the Qin State to enter the Central Plains in the east, so Korea must be the first target of the Qin State to attack.
For this situation, the Korean monarchs are well aware that although the strength is the weakest of the Seven Heroes of the Warring States, they will not sit still, and at this time Zheng Guo is out of the horse.
With a large difference in strength, South Korea did not have many ideas, and could only come up with a clumsy solution, that is, the "tired Qin" plan.
The so-called "tired Qin" is to send Zheng Guo to the Qin State as an envoy, using the repair of canals as a pretext, so that the Qin State will invest a large amount of manpower and material resources in local construction, and has no energy to use troops abroad.
Although this method is clumsy, but the effect is very good, subjectively speaking, Zheng Guo is a Korean spy who infiltrated the Qin State, but from the objective effect, the canal built is quite beneficial to the Qin State, so Zheng Guo did not spend much effort to convince Qin Shi Huang.
However, although Zheng Guo was a great water conservancy expert, he was not a competent spy, and his true identity was discovered not long after he was in the Qin State.
The "Records of History" records that Zheng Guo, a Korean, came to Qin to make a canal for irrigation, and he was already aware.
In the eyes of many people, this is a big thing, but during this special period of the Warring States, espionage activities were quite frequent, and Qin Shi Huang could not talk about how angry.
However, this incident set off a frenzy in the Qin Kingdom, implicating all the guest secretaries of the Six Kingdoms in the Qin State, which stemmed from the mutual struggle between the forces within the Qin State.
Since the Shang martingale reform law, the power of the local nobles of the Qin State has been greatly hit, especially the Six Kingdoms Keqing has gradually filled the Qin Temple, and the rights and interests of the local forces have become smaller and smaller, and the most representative is the Ying clan relatives.
After the Zhengguo incident was exposed, the local forces of the Qin State took advantage of the problem to frame all the Guest Qing to come to the Qin State for not simply, and Qin Shi Huang was angry for a while, ordering the expulsion of all the Six Kingdoms Guest Secretaries, fortunately persuaded by Li Si, otherwise qin would have changed again when the Six Kingdoms were destroyed.
The "Records of History" records that the princes who came to Qin were mostly in Qin'er for their main tour, and they invited all the guests to be expelled.
After the incident, Qin Shi Huang not only did not punish Zheng Guo, but also put him in charge of building the channel, which was for two reasons.
First, the Six Kingdoms of Kwantung are no longer rivals of the Qin State, and even two or three families cannot fight the Qin State together, so this trick alone is simply not enough to resist the Qin State's plan to advance eastward;
Second, the Qin state often won foreign wars, but it could not withstand the years of poor soldiers, and without a steady stream of logistical support, no matter how strong the Qin generals were, it would not help.
After the construction of the channel, Guanzhong will inevitably become another large granary after Shudi, laying the foundation for the subsequent annihilation of the Six Kingdoms by Qin.
More than ten years later, the channel was built, the swampy saline land became a fertile field, and Guanzhong became the richest area in the world.
The "Chronicle of History" records: Canal is on, so Guanzhong is fertile, no fierce year.
This channel allowed Guanzhong to produce more than three times the grain in other regions, directly supporting the qin state's war to unify the six kingdoms, and in order to commemorate the merits of Zheng Guo, Qin Shi Huang named this channel after him, which is the origin of Zheng Guoqu.
(Reference: Chronicle of History)