Guan Yu sieges Jincheng for many days. Although he also relied on the catapult car to destroy some of the annexes on the city walls, considering that the Han Sui army in the city is still crowded with people, even if the battle of attrition can cause huge losses to the Han army, he was unable to make up his mind to pile up his lives and fast attacks and strong attacks.

In the era of cold weapons, no matter how strong the catapult car is and how simple the city’s defense facilities are, it only weakens the degree to which the defender takes advantage of the city. It is impossible to completely erase the additional bonus of the offensive and defensive sides - this is a living war, not a game against the Imperial Age.

So after welcoming Li Su, Guan Yu was very enthusiastic at the first time. He led Li Su to the Gaolan Mountain Camp in the south of Jincheng City, took out his telescope and asked Li Su to climb up to see the enemy situation, and discuss countermeasures.

"Boya, can you see the camp arrangements that siege the Jincheng, can you be strict? I just regret that Han Sui is also aware that he has been defeated many years of battles and has no desire to fight. He only has more than 20,000 combat soldiers and more miscellaneous soldiers brought by the thieves, but he still refuses to leave the city to fight.

At the beginning, I chose to encircle three and one, and gave Han Sui the route of running downstream along the Yellow River Valley to the east, but he was unmoved. Two days ago, I asked Wang Ping to take only two thousand people to the enemy's east side of the city and camp on the edge of the Yellow River.

He deliberately showed the enemy that he wanted to use these two thousand people to destroy the houses and docks outside the downstream city, and search for ships. He wanted to force Han Sui to stay calm and concentrate his troops to raid our army and eliminate Wang Ping. But Wang Ping's bait was so weak that Han Sui didn't even have the courage to swallow it."

Guan Yu's words were full of contempt for Han Sui's courage. He was too judging others by himself, and always felt that "he gave you such a good opportunity, and you still dare not fight."

The weather was hot at the end of May, and Gaolan Mountain was not much better in the north. Li Su was panting in the mountain. She first held a folding fan and sang it for a while, then covered the open fan on her eyebrows, blocking the sunshine and looking at it intently. After thinking about it, she asked:

"If Han Sui was completely out of the trap, how long would it take for our army to capture Jincheng in the worst case?"

Guan Yu obviously had done his homework in the past few days and had also tried to attack the city several times. He had a very clear understanding of the enemy's strength, so he answered without thinking:

"Just fight as step by step. In more than a month, you can smash the city gate and city wall into several places, or use other methods to destroy the city defense. Then it depends on Han Sui not going back to fight the trapped beasts, because he knew that he could not be pardoned by the court and fought to the end.

At the fastest time, the Battle of Jincheng can be ended in forty or fifty days - but the key now is that we are already limited by the supply of military rations and will go to war in May.

The hot season for combat in the year is only four months, and it is not affordable. Once autumn begins, the colder the more you go north, how can you delay here for so long?”

Li Su immediately judged: "That's really too long. Jincheng will hold our army back for at most half a month. This is acceptable. If there are more, it will not be enough to attack Guo Si and other anti-Han Qiang Kings.

Have you considered asking Boqi to lead the cavalry, first along Langshui to attack Wuwei County and Lingzhi County, and even threatening Guo Si’s old camp Guzang?

We left a army to monitor Jincheng and pretended to look down on Han Sui at all, not afraid that he could beat the partial army we left behind, not afraid that he would leave the city to cut off our army's food route.

If Han Sui was still calm, we would continue to surround us until the time when autumn grain could be harvested in July and August, we would divide our troops to harvest all the wheat fields in the Huangshui and Taohe Valleys, and even the wheat in the Yellow River Valley near Jincheng would be collected.

Let the enemy's autumn harvest this year become our army's rations and support our army to continue to advance north. If Han Sui was still calm and became a turtle at that moment, it wouldn't matter. He cages the city for several months, and he will probably be starved to death, and the city will be destroyed by then.

If Han Sui finally couldn't calm down and was forced to fight a decisive battle with our army's partial division, then we would use that partial division to severely damage Han Sui in the battle of offense and defense to seize the city.

However, if this plan is realized, it depends on your combat strength. If you leave more troops, Han Sui dare not respond. Bo Qi's troops are not enough to surround Guo Si, and it is not enough to seize the autumn harvest of wheat fields along Lingzhi County, Guzang County and Langshui River Valley.

If you leave fewer troops, Jincheng cannot defeat Han Sui, which will make things worse. The wonderful use lies in the fact that the enemy is strong, so that the enemy dare not fight, and the real one shows that the enemy is weak, so that the enemy cannot calm down."

Li Su's words are very correct in principle and are also very insightful.

But the key is that there is no operability. Talking about principles and not tricks is a poisonous chicken soup that is "only giving you chicken soup but not a spoon", which makes people unable to drink.

Guan Yu listened, absorbed his spirit, and then smiled bitterly: "It's not easy to say it well. Military strategy emphasizes the correspondence between virtual and real, and also focuses on concentrating superior forces to defeat each other. We are virtual and real, and we are also deliberately creating divisions and weakening for our own side. We originally wanted to defeat Han Sui and Guo Si one after another, but now we have to deal with two families at the same time."

Li Su: "No hurry, let's wait and see if there is any possibility of any of the battlefields to lure the enemy at a very small cost, and be able to fight quickly and win quickly."

...

Li Su is not a god either. He had just arrived around Lanzhou, Gaolan Mountain and the Yellow River bank, and had not traveled everywhere. When he thoroughly observed the battlefield terrain, he could only give general opinions, and the rest had to be analyzed in detail.

He knew that this matter was necessary to practice it. So in the next few days, he conducted in-depth research with Guan Yu and Xu Shu and gradually revised the plan.

However, no matter what the specific plan was, he first instructed Ma Chao to make preparations to bypass Han Sui and continue northward to ensure that he could continue to walk at any time.

Moreover, the caravan convoy did not stop for a day. After arriving in Jincheng, they immediately returned empty-handed. They arrived in Lintao to stock up on the second batch of goods and increased the material reserves in front of the army. Basically, the caravan convoy could travel back and forth from Lintao to Lanzhou in about ten days.

Anyway, Lanzhou is the hub of four provinces and four rivers, and the Yellow River, Tao River, Huangshui and waves all converge at the mouth of Liujiaxia, so no matter where you want to fight in the future, it is definitely correct to stock up more materials in Lanzhou. No matter where you go next, you have to start from here.

On the fifth day of June, three days before the caravan convoy was about to arrive in Lanzhou for the second time. Calculate the day, the convoy should have passed Didao and was about to enter Liujiaxiakou.

In the past few days, Li Su has been focusing on his ideas of "building a water storage lake, diversion canal and dam in Liujiaxia, and developing it into a northwest industrial and commercial center" and told Guan Yu.

Moreover, in the past few days, he had no time to send the second-tier besieged troops who had nothing to do to transport the Tao River into the estuary area of ​​the Yellow River, built the river bank a little, and dug a short channel to improve shipping conditions.

This operation saves a lot of manpower than building large-scale dike water conservancy facilities. It is just a temporary measure. The purpose is to make the acute angle between the two rivers converge into an obtuse angle, preventing the two reverse water flows from storm to form vortexes, and rolling the vortex of the boat or schooner.

The reason why Li Su was very familiar with this kind of construction was because when he was in charge of the prefect of Shu County, he repaired the Leshan Weiyan in Nan'an, Jianwei, and solved the shipping problem. The location of Leshan Giant Buddha in history was because the water flow converged when the Dadu River and the Minjiang River intersected, and the vortex was very harmful.

Guan Yu originally didn't care about these post-war economic reconstruction work. After all, he just wanted to fight a war now, and nothing else was seen.

There was no good plan for several days. He could only use catapults and crossbows to consume the defenders in the city and destroy facilities. There was nothing else to talk about. He was bored and listened to Li Su talking about these things.

Unexpectedly, Li Su’s temporary water conservancy measures were unintentionally planted, but instead activated Guan Yu’s inner combat experience. Guan Yu had achieved a brilliant record of “flooding Chen Cang and killing Zhang Ji” in the battle of Chen Cang a year and a half ago.

People are always prone to path dependence, and they consider the priority of whether they have the chance to be used on the battlefield.

So Guan Yu could hardly help but think, "Since Liujiaxia is so easy to open canals, cofferdams, and store water with a little construction", then "Can another flood of Jincheng come to another place?"

Guan Yu immediately discussed this idea with Li Su, and complained that Li Su didn't expect it: "Boya, this is not like you. I don't understand geography or hydrology. Since you understand so much, you didn't say it earlier."

Guan Yu knew tactics, but his knowledge of science and engineering was not systematic enough. In history, he was able to flood the Seventh Army in the Han River because he had been operating that place for more than ten years and had figured out the environment. It was the first time he came to Jincheng. No one mentioned it for at least a year or two to fully understand the weather and geography.

Li Su immediately told Guan Yu about the difficulty of this plan: "Jincheng is not as good as Chen Cang, and it can be captured without being too vicious, and there are also many innocent people in the city.

On the other hand, we fought Chencang before spring plowing, so we could not delay spring plowing. It is early June now, and there is still more than a month to harvest in autumn.

If water is released, all the fertile valleys on both sides of the Yellow River outside the city will be flooded, the wheat fields on both sides of the Yellow River, which are two or three hundred miles deep, will all suffer—

This will create huge obstacles for us to appease the people of Jincheng and build this place next year. These foods that should have been our military rations will be gone and will be very unfavorable to the subsequent offensive.

If I really get to this point, I don’t think I’d better just take down Jincheng and Wuwei this year and then turn to defense. At least I can digest these areas first, and the people’s hearts are on me. I will chase Zhangye Jiuquan next year.”

Guan Yu pondered for a while and had to nod. Indeed, things will be different when times change. The current seasons are very unsuitable for the scorched earth policy, which will cause too much harm to the people and long-term governance.

However, Guan Yu still searched the memories of his working with Li Su over the years, and soon remembered a trick: "Boya, I remember when you were in western Liaoning and Youbeiping, you thought about letting the people rush to harvest wheat and bake and grind them as a strategy for military rations.

If you can harvest in advance and make it into a rotating process, at most, the time for the wheat storage is shortened to two or three months, and the harvest loss is 20 or 30%.

But since our army has transported a large amount of military rations, we can let the troops eat the new wheat harvested in Jincheng River Valley first, and then sell the transported old grains to the people outside the local city for winter and next spring famine. Although the people will eat 20% less after famine, they will not starve to death and not survive next year.

As long as you control the time and scale of the flooding city, ensure that the depth of the flat ground is not more than one meter, and the time should not exceed a few days. If there is a barrier between Jincheng City walls, then the city walls will be soaked even more so that they can be broken everywhere and people will not drown in the city. That would be the best of both worlds."

Li Su shook his head: "How easy is it? Normally, autumn harvest is about the end of July, and the northwest is already cold and the crops are ripe slowly. Even if the harvest of green yellow wheat is changed to be used for rotation, the harvest in early July is the earliest, and it cannot be any longer earlier - that is almost a month later.

And when we are snatching the wheat, how much troops should we leave in Jincheng? By then, the Wuwei Battle will definitely enter a fierce offensive and defensive stage. The few people Bo Qi took away were not enough to threaten Guo Si, and the many people he took away were not enough to protect us to harvest wheat. If the wheat harvest troops were really swallowed by Han Sui out of the city, it would be more and more unworthy of the loss."

The two of them looked at each other speechlessly, and there was no better way for a moment.

There are too many difficulties.

At this moment, Xu Shu, who had been following Li Su to the northwest since early summer, suddenly made a suggestion next to him:

"Right General, former General, I have a plan and I am willing to say something boldly: The tactics we mentioned before that we have not considered another possibility - we can use much lower water levels and water volume, and we can also use a little earlier than the wheat harvest in early July to complete the temptation of Han Sui's enemy, and then flood Han Sui's troops outside the city until their combat effectiveness is sharply reduced, and then destroy it."

Guan Yu's eyes lit up, but he was a little reluctant to believe it.

Although Xu Shu claimed to have studied military tactics for many years, he might not be able to understand actual combat, right? Han Sui was an old thief who had betrayed the court for twelve years!

"How to do it?" Li Su encouraged.

Xu Shu: "Did the general forget? Our car is not afraid of flooding. The ox that pulls the cart will not be drowned or washed away by half a foot deep water. And when it comes to water release, you can concentrate the livestock and supplies to a high place to hide in advance.

In this way, combined with the best of both worlds you just mentioned, we will have: let General Bo Qi divide his troops north, and after halfway through June, General Bo Qi becomes the absolute main force. He really only has a small amount of troops left on Jincheng, and despise Han Sui.

When it comes to the time to harvest wheat, we not only have to camp at high places, but also camp in the fertile and low-lying places of the Jincheng Valley to block the city and grab wheat! In this way, the enemy will never think that our army will dare to block the Tao River and Huangshui River and wait for it to flood, because that will make it even our army drown together?

In this way, when they really find that our army is robbing wheat and surveillance of Jincheng, they will definitely feel that our army is too bullying. At that time, they will bet out of the city and destroy the surveillance force, and they will be able to cut off the general's rations. This bait is large enough.

As long as our army encounters the enemy's army leaving the city, we will hold the camp to the road for a long time, even if it is surrounded by the enemy army. As long as the military information is reported at the first time, the horses and even the beacons will be released immediately. At that time, even the camp where our army's city blocks the city and grabs grain will be flooded with the enemy's field surrounding the camp. Our army can hide in the caravan to avoid water, and take advantage of the unstable position of the enemy's army, turning into a caravan to rush into a boat. Even if thousands of people are broken and tens of thousands of people will not be difficult."

Since there are amphibious and land armored vehicles, of course, they have to fully utilize their characteristics in flooding and luring the enemy into battle. How can the original flooding seven armies be enough?

We use ourselves to drown ourselves to deceive the enemy into being careless and take the bait. When the flood comes, our car will instantly turn into a ship. Even if the enemy has the speed of reaction, it is destined to be caught off guard.
Chapter completed!