At this time, Chu Ze completely rejected Cen Wenwen's proposal, and seeing that Cen Wenwen had nothing to say, the eldest grandson Wuji, who had been arguing with Cen Wenwen for a long time and gradually became a little angry, felt very happy. But immediately after His Majesty Li Er's words, he had a bad premonition in his heart.

"Chu Ze! The auxiliary machine proposed to lower the water level of the Wei River by dividing the water of the Wei River into two rivers, so that the Wei River would not break its embankment. What about this method? His Majesty Li Er asked again.

Chu Ze thought for a moment and said: "I'm afraid this method won't work, just imagine that after the Wei River is diverted, although the water surface will be lowered for a short time, the water potential will definitely slow down." As the water slows down, more sediment will inevitably be deposited than before. The more sediment is deposited, the higher the channel will be. Day after day, year after year, it accumulates over and over again, and in the end I am afraid it will become a boat on the roof. ”

Smashing his lips, Chu Ze continued: "Therefore, the method of diversion may solve the flood of the year, but in the long run, the disadvantages of this method far outweigh the benefits. Even as time goes by, before the Wei River breaks its embankment and flows into the world, it will become more and more frequent. ”

When the eldest grandson Wuji heard what he said, it was even more unbearable than Cen Wenwen's sand digging method, how could he have been denied like this with his identity. couldn't help but feel a little feverish, especially when he saw Cen Wenwen's smiling expression on his face, he was even more unhappy, and couldn't help glaring at Chu Ze.

Chu Ze pretended not to see it, but he was still thinking about the princess in his heart, thinking about how to open his mouth to the Great Demon King Cheng later and ask which princess it was.

"Then Chu Ze, what is your best plan?" His Majesty Li Er didn't want to listen to everyone's arguments anymore, and he felt that what Chu Ze had just said was reasonable. So ask directly.

Chu Ze has also heard a lot about the management of floods in later generations. As long as you have attended junior high school, high school, or studied geography, you will know some of the effective solutions in the future, and the main ones are two points: one is to plant grass and trees along the river, increase vegetation, and prevent water and soil from being lost into the river. The second is the construction of a large number of reservoirs.

After Chu Ze pondered for a while, he sorted out his thoughts and thought about how to use the words 'soil erosion', 'overflow capacity' and 'artificial flood peak' to explain to everyone in the words of the world.

Under the gaze of everyone, it didn't take long for Chu Ze to say: "First of all, I will analyze the root cause of the Wei River flood, and then tell you how to deal with the Wei River flood." ”

Without waiting for everyone to think about it, Chu Ze then said: "There is a lot of sediment in the water of the Wei River, do you know where this sand comes from?" ”

Everyone pondered, Cen Wenwen snorted coldly, and said: "Naturally, it is the upper reaches of the Wei River and its tributaries, which wash the sand and soil above the mountains and rivers that flow through and bring them into the main river of the Wei River, and then accumulate down the river to the middle and lower reaches of the Wei River. ”

Chu Ze nodded and said: "What Lord Cen said is right, but Lord Cen knows that the rain in the south is ten times that of the north, and the water potential of the Yangtze River is far greater than that of the Wei River, why is there no sediment in the Yangtze River, and even fewer embankments?" ”

Everyone's eyes flashed, thoughtful, Cen Wenwen couldn't figure out the reason for a while, but he simply said: "The old man doesn't know about this matter." ”

Chu Ze saw that everyone's thinking had been completely mobilized by him, so he said: "The reason for this is that there are many trees and dense vegetation in the south, and wherever there is soil in the mountains, there must be a lot of vegetation. Wherever the Yangtze River basin passes, even above the mountains and rivers, the roots of trees and plants firmly hold the soil in place, making it difficult for rainwater to wash away, and naturally it will not collect into the Yangtze River. ”

"In the upper reaches of the Yellow River, there are many barren mountains in the west of the river, and when there is rain, the muddy water will flow into the river. Therefore, if you observe carefully, you will find that whenever the mountain is covered with grass and trees, the water in the mountain will be much clearer. The reverse is true. ”

Including His Majesty Li Er, everyone listened to it, and they had never heard anyone be able to explain the flood of the Wei River from the root to Chu Ze so clearly.

The truth of soil erosion has never been put forward in this era, and as soon as Chu Ze said it, everyone fell into contemplation again. However, everyone present was extraordinary, and although it was the first time they heard this truth, they felt justified after a little thought, and they couldn't help but nod their heads one after another.

"A few days ago, I heard that the Wei River was silted up due to the river's water, and the river must be cleaned up every year, but even so, it still can't keep up with the speed of the riverbed rising." Chu Ze said again.

Hearing this, everyone nodded yes, and they also knew that near the mouth of the Wei River into the Yellow River, the boats in the embankment were even higher than the roofs outside the embankment, all because of the sediment backflow, and in order to dredge the Wei River, a large number of laborers had to be recruited every winter. The people on both sides of the Wei River are suffering unspeakably. And this is because the Wei River is much narrower than the Yellow River, otherwise if it is replaced by the Yellow River, it is possible to cause a civil uprising.

Chu Ze took the opportunity to say again: "Therefore, the root cause of the Wei River flood is to plant trees and vegetation on the Loess Plateau and barren soil mountains in the Wei River basin in Longyou and Hexi in the upper reaches of the Wei River. ”

At this moment, everyone's brows furrowed, and Chu Ze didn't wait for everyone to make trouble, so he took the initiative to say: "Presumably Your Majesty and your lords have already thought that this method is certainly a method to cure the root cause, but Guanxi, Longyou, and Hexi are all loess piled up into mountains, and if you want to make the mountains covered with grass and trees, I am afraid that it will take a hundred years to do it." Therefore, this law is the work of long-term governance, not the law of the moment. ”

His Majesty Li Er's eyes flashed with an inexplicable light that made people break their hearts, and said: "Even if it is not a hundred years of work, this method of curing the root cause must be implemented, and it will be persisted for a long time, my Tang generation will not work, then two generations, or even three generations, I don't believe that after a hundred years, I can't do this." ”

When Chu Ze heard this, he couldn't help but sigh with emotion in his heart, and sincerely admired His Majesty Li Er's eloquence and long-term vision, but he was really not optimistic about His Majesty Li Er's ideas and goals.

In the future, the power of manpower, the power of machines, and the power of seedlings, how many years have passed, and most of the barren mountains in the land of Kansai and Hexi are still mostly bare on the Loess Plateau.

It's not that the government doesn't pay enough attention to it, but that there are too many destabilizing factors involved. The factors of people themselves are also due to the fundamental defects of the dry and lack of rain in the northwest.

In short, Chu Ze really didn't think that this thing could be done by a feudal social dynasty. But he would never say these words to His Majesty Li Er.

I didn't look at this meeting, and several important ministers successively said things like 'Your Majesty's Shengming' and far-sightedness, 'The deeds of the Holy Gods are in the future'. Speaking out at this time, it is clear that you are unhappy for yourself and everyone!

Chu Ze hesitated for a moment, avoided planting trees and planting vegetation, and said: "The minister proposes that from Guanxi and Guanzhong to Xihe Road, logging should be prohibited on both sides of the Wei River, otherwise if the trees in the mountains are cut down, there will be more and more barren mountains, and the sediment in the river will continue to multiply, and the Wei River will inevitably become more difficult to control." ”

Everyone thought it was true, and His Majesty Li Er directly said to the eunuchs who were in charge of transmitting the decree on the left and right: "Write down this matter, go back and explain the reasons, and then set the corresponding laws, and then immediately issue an edict to the roads, states, and counties that the Yellow River valley passes." ”

After finishing speaking, His Majesty Li Er thought for a moment, and then said to Chu Ze: "Chu Ze! This method of curing the root cause has already been said, but there are other ways to work in a short period of time. ”