After receiving Xu Shu's reception, Li Su and his party's follow-up inspection work immediately became more organized. The two of them walked hand in hand and took a quick look under Xu Shu's explanation.

The water conservancy project in Liujiaxia was originally planned by Li Su's staff based on the technical experience summarized in Dujiangyan and Leshanyan. After all, Li Su is not an engineering student and does not understand the specific details of engineering exploration and design. It would be nice if he could know a guiding idea.

However, after all, the natural environment in each place is different. Many things need to be surveyed and adjusted according to local conditions. Therefore, after several months of rushing work, what Li Su saw at this moment was also very different from his initial expectations.

The only thing Li Su could do was to transfer all the technical design talents he had accumulated in Yizhou to Xu Shu.

Xu Shu pointed to the estuary area where the Tao River flowed into the Yellow River and the reservoir area next to it, and said: "Just Right General, you first sent water conservancy technology officials from Yizhou to copy the Leshan Weir. But in July last year, after the first field survey, I found that this would not work.

Because the difference between dry and abundant water in the northern rivers is too big, not as good as the wet Shu area. Although there are floods and droughts, the difference between the highest and lowest water levels of the Minjiang River is only two or three meters. Here, the Tao River has a month that is almost cut off from the middle of the twelfth lunar month to the beginning of the first lunar month every year!

The lower reaches of the Huangshui River enter the mouth of the Yellow River, and there will be a dry season with almost no flow for two months. On the one hand, there is less rain and snow, and on the other hand, it is cold and it is frozen directly at the bottom. The only little water is frozen because of the slow siltation flow rate in low-lying areas.

Therefore, we dug many relatively low-rise areas from the estuary, and directly led the Tao River and Huangshui River to the nearby valleys during the flood season. After the water level was leveled, the lake mouth was slightly blocked and slowly dug it out when it was dry.

In general, it is to strive to achieve the effect of storing the Yangtze River in Yunmengze and Penglize in the Yangtze River. Of course, the scale is definitely at least a hundred times smaller than that in Yunmeng and Pengli."

In ancient times, water conservancy construction was built, and it was impossible to directly block water and dams to cut off the entire river. It was impossible to do it, and it could only be diversion and divert floods. Therefore, the overall idea would not change. The final effect was not a reservoir in later generations, but it could only be said to be a landslide lake.

Just like Dongting Lake, Poyang Lake is actually the case when the Yangtze River turns to a low-lying area, and accumulates a large amount of surplus water in these two lakes. When the Yangtze River water level drops, the lake water will feed back to the Yangtze River.

Therefore, the amount of this kind of diversion project is relatively small. As long as there is a suitable terrain that can be transformed into a reservoir area, with a little manpower, at most, tens or 20,000 workers will be killed, and the work will be piled up.

Of course, it is better to try not to die. The most dangerous corvee labor force is to let those old thieves under Han Sui who have rebelled for more than ten years to do it.

Their lives were not their own, which harmed the Han Dynasty for more than ten years and dragged down the entire world.

Let them complete the Liujiaxia Reservoir completely, which may take several years to complete the construction period. If they finally live to the completion date of the project, they can restore their freedom and no longer have to be lifelong slaves, which is considered to be a redeeming their sins. (Those who were directly drowned by Guan Yu's water attack last year are even more straightforward, and they don't have to drown slowly while repairing water conservancy)

...

As the saying goes, when guns and cannons fire, all the plans of the General Staff will be abolished. At the end of the Han Dynasty, once the construction starts, all kinds of difficulties that were unexpected at the beginning will also emerge. In comparison, what Xu Shu and Li Su explained just now are still small problems.

Soon, Xu Shu took Li Su and continued to visit downstream along Liujiaxiayan. Many water irrigation canals were dug by the repaired river banks, and more than a hundred water trucks had been built. However, according to the scale of this project, it is necessary to have thousands of water trucks in the entire Lanzhou area in the future, so less than 100 were built.

Xu Shu explained: "According to the original plan, there is still a problem in creating a waterwheel spinning and grinding surface here, which will cause the waterwheel spinning machine to pay the cost time, at least half as expected.

For example, according to the figures originally provided by the craftsmen, when they were in Dujiangyan, the water truck could make a return in less than two years, because the weirs and canals there were ready-made, and as long as the cost of a water truck spinning machine was invested, it was very profitable. When it came to Leshanyan, according to the experience of General Guan’s soldiers, it was said that it would take more than five years to make a return in three and a half years to make a return in the money of repairing the weirs, and more than a half years to make money in the water truck spinning machine.

When it comes to Liujiaxia, even according to the profitability of the water trucks in Shu, the water conservancy itself has a larger project volume and fewer other industries that can share the cost. The dike and irrigation canal alone will cost five years. What’s more troublesome is that even if there are dams and lakes that have peaks and valleys, the water volume and flow rate are still lower than the necessary impact of the water truck starting work. Therefore, there can only be eight months a year for spinning and grinding surfaces, and the remaining four months of the machine is idle."

Previously, Xu Shu said, "The flow is cut off for at least two months every year", which is aimed at the extreme situation of "complete flow cut off". In fact, even if the flow is not cut off, the river cannot drive the water truck all year round. The shallow water will lead to inefficiency and even inability to move.

This is also why the hydraulic industry was difficult to popularize in history. It was only when the steam engine was invented. If it were not for Li Su, according to the original development of Li Shi, the Dujiangyan area could only be used to build large-scale waterwheel textiles until the end of the Ming Dynasty. No other places could do it.

Even in the middle and lower reaches of the Yangtze River, although the water volume is abundant, due to the low drop, the water speed is too slow, and the impact force is still insufficient. There is no shortage of water in Jingchu and Wuyue, but it lacks "water energy".

In fact, using the well-known common sense taught in geography classes in later junior high schools, we can explain this problem. The geography of China is roughly divided into three levels of altitude. Only when the flow of the rivers and the current engineering technology scale can you directly cross the ladder faults, can you develop water energy on a large scale in this way.

In other words, whether it is the middle reaches of the Minjiang River where Dujiangyan is located or the Liujia Gorge in Lanzhou, they are actually key points for the first step to the second step to the Huaxia, using the water energy of the Yangtze River and the Yellow River rushing down from the Qinghai-Tibet Plateau.

Such a location cannot be replicated geographically. Some people may think that the place where the Yangtze River and the Yellow River descends from the second stairs to the third stairs has a chance, but in fact, the two places are Sanmenxia and the Yangtze River Three Gorges. The water volume of the Yellow River and the Yangtze River is so large that it is definitely not something that humans can control before the industrial singing.

So to put it bluntly, even if all of Li Su's technical means of farming were leaked, geographical decisions also led to the large-scale "hydraulic textile/forging/grinding of grain" that could not be copied by Yuan Shao, Cao Cao and Sun Ce.

Liu Bei's rise from the West was destined to lose the advantages of the eastern plains and maritime trade. He would always earn it and earn it exponentially in the field of industrial energy.

As for Xu Shu’s mention of “there are fewer other industries that share the costs of water conservancy facilities”, this sentence may not be understood by laymen, which actually means “we need to rely on the higher proportion of water conservancy costs shared by the water truck industry.”

This is because when I was in Yizhou, Li Su discussed a "532" allocation plan with Liu Bei, which shared most of the cost of water conservancy repairs by the benefits of farmland irrigation of the people along the coast, and 30% of it will be borne by the toll of the shipping cargo ship, and in the end, only 20% will be borne by the owner of the water truck.

But the problem is that after Yizhou has developed commerce and industry, there were many cargo ships coming and going on the Minjiang River. They made it convenient to navigate, so it was normal to charge more tolls. However, Lanzhou had not yet established a commercial atmosphere, and there were very few private caravans, so the proportion of reimbursement by collecting tolls was reduced. Only the proportion of water truck factory owners could be charged, and the time it took for water truck owners to pay back the capital was longer.

Not everyone can compare with the Tianfu country like the Chengdu Plain. After a few moments, it will lose a little bit east and a little bit west, and the return on investment will be more than half.

Li Su also listened to these troubles raised by Xu Shu very seriously, and finally encouraged him: "The difficulties I didn't expect at the beginning must be a lot, and I even worked more and more. But as long as I stick to a big direction and know that it is right to work hard here, then continue to work. Originally, if the water truck could only run for eight months a year and was idle for four months a year, it would be extended to nine years to recover!

I will convince the king not to have too much expectations for the people who are rich in Liangzhou. Perhaps within four or five years, I will not expect the Liangzhou people to spend much money and grain to support the court to pacify Guandong. Let the Liangzhou people find their own way to survive and work hard without any unstable situations. This is the greatest contribution to the Han Dynasty. We can accept taking it step by step."

With Li Su's attitude, Xu Shu finally became more and more open-minded in his work, and he didn't have to worry about losing money temporarily. In the past six months, his level of organizing local government affairs has also improved a lot. In time, he might become a famous minister.

Li Su always felt that as a civil servant, he had to have certain internal affairs skills, and did not seek to be very good at it, at least he had already organized and experienced it. Otherwise, he would be a purely adviser and would easily work behind closed doors. In history, Zhuge Liang's early years of office, he also coordinated the money, grain and military supplies of the four counties in Jingnan, and worked in the logistics internal affairs for a long time.

After chatting with Li Su for a while, facing the various problems raised by Xu Shu, Li Su thought for a while and called Zhuge Liang, who was still running around to inspect himself, took out some of the planning difficulties, and saw if Zhuge Liang had any ideas.

Xu Shu in this life had no personal relationship with Zhuge Liang. When Xu Shu followed Huang Chengyan to Hongnong the next year, he heard about Zhuge Liang's deeds. However, Xu Shu was a low-key person at that time and only played a guest appearance as a bodyguard for Huang Chengyan to see the world. He was not qualified to enter the emperor's palace and imperial prelude, so he had never met Zhuge Liang.

At this moment, Li Su called Zhuge Liang to discuss together. Only then did Xu Shu realize that the person in front of him was the legendary Xu Sui 15 who refuted Yan Xiang and Zhuge Liang, the spiritual commander of the evil saying of astrology and celestial beings. He also quickly treated Zhuge Liang humbly.

Then, Xu Shu noticed that Zhuge Liang had a stop next to him, a girl of up to twelve or thirteen years old, wearing a veil in a hat. Xu Shu looked closely and recognized her even though she was wearing a veil: "Junior Sister Huang? Did Mr. Huang let you go on a long trip?"

Xu Shu studied under Sima Hui when he was in Yingchuan, so he always referred to Huang Chengyan as his uncle and nephew (Sima Hui and Huang Chengyan brothers). He was a little surprised to see Huang Yueying.

Although Huang Yueying is young, she is generous: "My father agrees that I will go around with Zhuge Lingshi and have some knowledge. Brother Xu, your plan here is not very good. Brother Liang just saw a few things and thought it could be improved."
Chapter completed!