In order to prevent the country from being destroyed by Qin, why did South Korea send water conservancy experts as spies?

In 262 BC, Qin launched a war against South Korea again. Previously, South Korea's territory was constantly being eroded, and the originally slim land became a bit slim, sandwiched between Zhao and South Korea like a horn.

As the saying goes, Qin decisively sent troops to occupy the wild king and cut off the "long and narrow corner." As a result, Shangdang area became an enclave of South Korea.

What should we do with this enclave?

This enclave is not easy to manage, so give it away. Who is it for?

Qin was of course the idea of Han Huanhui and the central government. Facing the heyday of Qin, South Korea wanted to save itself and chose to "cede territory to pay tribute to Qin".

South Korea may have no problem doing this. This is an enclave, which is inconvenient or even unmanageable. Sooner or later, it will definitely be taken away by Qin. It is better to be a good man and give it to Qin, which can also make the base camp more peaceful for a few years.

So this enclave in South Korea is really out of control?

It's really out of control. South Korea wanted to give this land to the State of Qin, but Feng Ting, the governor of Shangdang County, was unwilling to surrender to the former State of Qin. So he sent messengers to see Zhao, hoping to submit to Zhao and use Zhao's strength to fight against Qin.

Facing the fat mouth-Shangdang Seventeen Cities, Zhao was afraid of Qin's intervention, but after consideration, he accepted Shangdang, sealed the Huayang Army in Shangdang County, and sent Lian Po to lead the army to take over Shangdang.

An inevitable war broke out between Qin and Zhao, which is the famous battle of Changping.

In the battle of Changping, Zhao was defeated and his strength was greatly weakened. South Korea, the fuse, and South Korea, who watched the play, were frightened out of my wits when they saw this battle, and lost more than a dozen Shangdang cities in vain, and no one was pleased.

Watching Qin become so powerful step by step, what should I do?

South Korea may be inspired by the battle of Changping and send spies to bring down Qin.

So Han Huanhui sent a spy named Zheng Guo, who was a water conservancy expert.

Although Zheng Guo's name is Zheng Guo, he is Korean to the core. Zheng Guo was born in Xinzheng, the capital of South Korea. He is an outstanding hydraulic scientist. At that time, he worked as a hydraulic engineer in Korea and was a hydraulic technician in Korea.

Zheng Guo is just a water conservancy expert. Why did the spy task fall on him?

The reason is interesting. I don't know where Han Huanhui heard the news: Qin likes to engage in large-scale civil engineering! This can ruin Wang Jimin for Han Huanhui, since you like architecture? Then I'll do what I want and send someone to fix it for you.

Duke Huan of Han was very happy and prepared to send Zheng to Qin to help Qin build the canal. On the one hand, let Qin be busy building canals to achieve the purpose of "tiring Qin"; On the other hand, let Qin "play tired of the canal." In this way, Qin will not attack South Korea, and South Korea will be temporarily safe.

In this way, Zheng set off for Qin.

When Zheng entered the State of Qin, he didn't need to carry a heavy gift like Jing Ke. Only by relying on his water conservancy technology, Qin, which cherishes talents, will have his place. In addition, he is a peace envoy sent by South Korea, and he can easily meet the king of Qin.

In 246 BC, Zheng came to Qin, told Ying Zheng, the king of Qin, about the intention of making peace in Korea, and lobbied Qin to build water conservancy and irrigate agriculture on a large scale, which greatly increased Qin's agricultural income, thus better unifying the vassals and annexing the world.

The king of Qin agreed to Zheng's suggestion.

Zheng Guo led a group of Qin officials to travel across mountains and rivers, spend the night in the wind, survey the terrain and make detailed plans. A detailed plan and perhaps a story of embellishment, Ying Zheng, the king of Qin, approved his plan, sent hundreds of people to him to repair the canal and mobilized them.

Because of the terrain, it may be that the canal that Zheng specially found is difficult to repair. The construction of this canal is very slow. After several years, it is still unfinished. Spent a lot of manpower, material resources and financial resources, Qin people talked about it in succession, and Qin Wang also doubted whether Zheng was kind or not, and whether the people in the six countries were kind.

The king of Qin issued a "marching order" to arrest all the people from the six countries and drive them out of Qin, and Zheng was also arrested.

Qin Wang's "marching orders" may be just angry words. Later, Li Si, a Chu man, wrote a "Order of remonstrance and March", urging the king of Qin not to care about his birth, but to pay more attention to talents and the great cause of reunification. The king of Qin withdrew his marching orders.

Zheng Guo also advised the king of Qin in front of him: "I will help you build the canal, which can only help South Korea exist for a few more years, but it will be a great achievement for Qin!"

The king of Qin accepted Zheng's suggestion, and Zheng chose to be loyal to the cause in the face of national interests and continued to help Zheng build the canal. Qin also continued to "recruit".

Zheng Guo continued to preside over the canal restoration work. It took ten years to go back and forth, and the canal was finally built.

What happened to the canal after it was completed? Has it reached what Zheng Guo called "eternal power"?

According to historical records, it has been realized. Records in Historical Records:

After the completion of the canal, the yield per mu of the fields around the canal reached one acre, equivalent to six stones and four buckets. At that time, the yield per mu in the middle reaches of the Yellow River was only five buckets per mu.

This shows that the irrigation effect is very remarkable, and Qin has become fertile soil and a "land of abundance".

On the other hand, we can see that the irrigation effect is remarkable: the name of this canal is Zheng Guoqu. To thank Zheng Guo for his contribution, the local people named the canal after him.

What about Zheng Guoqu? Some people have commented that Zheng Guoqu's vast project, reasonable design, advanced technology and remarkable results are rare in the history of ancient water conservancy in China and even in the history of water conservancy in the world.

Later generations also called Dujiangyan, Lingqu and Zheng Guoqu as the three major water conservancy projects in the Qin Dynasty.

This is enough to illustrate the historical position of Zheng Guoqu.

Interestingly, after the completion of Zheng Guoqu, the State of Qin began to March eastward, and South Korea was the first to be eliminated. South Korea's move to carry firewood to put out the fire will inevitably make future generations laugh.