With the pencil, my master's writing and painting became more convenient. The most important thing is to make drafts, and the price is quite affordable and can be rewritten on white paper. Therefore, nowadays, the students of Qujiang Academy and Weinan Hope Yixue are all in one piece. Of course, our nation's brushes and calligraphy cannot be discarded.

For example, now, the pencil is rapidly outlining in my hands, and in a short while. In front of the two princes, a map of the evolution of the Guanzhong area in later generations that was eroded by flowing water, developed valleys, and divided into long strips of plateaus. "This... Brother Jun, are you saying that in a hundred years, our fertile Guanzhong Plain will become like this?"

"If we follow the uncontrolled cultivation of the past few years, the Guanzhong area of ​​our Tang Dynasty will definitely change greatly. Although my picture may be exaggerated, it does not mean that it will not happen. Moreover, not only Guanzhong, but also the lower reaches of the river will become a series of disasters in more than a hundred years..." I said in a deep voice. Yes, I am here, I exist, I change, and what I can do, and I can do as much as I can, to do the obligations and responsibilities of a time traveler who is familiar with the consequences of history from the future more than a thousand years later.

"Brother Jun, have you been asking for land replacement, try to move the population in densely populated areas such as Guanzhong to other areas, and ask my father to prohibit the reclaiming of fertile land in Guanzhong, all for the sake of this failure?" Li Zhi's expression also became solemn.

I didn't say anything again this time. At this time, all the officials who heard it were heard from the side were also squeezed over and asked what was going on to make us do this.

I can only tell the dozens of officials present what I understand about what soil erosion is, its formation and its long-term harm.

The Guanzhong Plain of Datang is located on the Loess Plateau. The loess particles are small, the texture is loose, the structure is loose and easily dissolved by flowing water, and are easily eroded and collapsed, which has contributed to soil erosion. Second, since the Qin and Han Dynasties, the population of the Guanzhong Plain has been growing rapidly, and uncontrollable reclamation and grazing has been destroyed, causing forests and grasslands to be destroyed, and the green vegetation has been severely damaged. The Loess Plateau has lost its natural protective layer, causing serious soil erosion.

What is more serious is that soil erosion significantly reduces the fertility of the soil, causing a large reduction in crop yields. The more the yield is reduced, the more people need to reclaim wasteland: the more land reclamation, the more soil erosion is more serious, forming a vicious cycle. In addition, vegetation is sparse and heavy rains in summer promotes the expansion of gullies, accelerating soil erosion. Grasp the erosion. Correspondingly, the valley slopes continue to expand, so the land between gullies is increasingly broken. It is closely related to social factors such as human activities, especially the excessive reclamation and destruction of natural vegetation.

Unfortunately, most of the dozens of officials and candidates working here have a half-believing expression. Can I still fool you with words? I was annoyed in my heart, but I didn't look like I said it on the surface: "I know that you will definitely not believe it just by talking. Although the data in my hands are evidence, I can find more evidence to prove that our Guanzhong Plain is in an unstable and dangerous period. Fang Cheng!"

In order to prove that every word we say is based on, I immediately asked Fang Cheng to go to my home in Weinan to get the books I usually collected. We have a habit of writing any information we use to check, posting it on the bookcase, and putting the booklets together for easy search. Soon, Fang Cheng held a bunch of booklets.

I directly handed it to the officials in front of me one by one, and said according to my usual memory: "Please read this book "Yu Gong", "Shan Hai Jing. Beishan Jing" and "Han Shu. Geography" all record that at that time, the lower reaches of the Yellow River flowed through the Hebei Plain and entered the sea on the west bank of the Bohai Bay. Because there were no embankments on both sides, the river channel was extremely unstable. According to literature records, the Yellow River had been redirected many times... Do you know what the reason is? It is because the mud and sand carried in the river accumulated the original river channel of the river, which forced the river to wander and divert, or divert multiple streams."

I opened one book after another and turned it to a place with clear records, and handed it to every official around me, Cui Renshi, Wang Fangyi, and Di Renjie. I kept explaining and describing everything I knew. These were recorded in the books, but we didn't brag, and even recorded in history books, which further proved the accuracy of my words.

"... From the end of the Western Han Dynasty, the rivers and rivers in Junxian, Henan were both higher than flat land, and it was obviously a hanging river. This was the result of the intensification of soil erosion in the middle reaches of the Yellow River since the Qin and Han Dynasties. At that time, the Yellow River broke into the east of Yuancheng, Weijun, and the river water continued to flood to several counties east of Qinghe County. At that time, because the river broke into the east, Wang Mang could not threaten his ancestral tomb in Yuancheng, so he did not advocate blocking the mouth. He believed that the flood lasted for nearly sixty years, thus causing the second major redirection in the history of the Yellow River."

After the beginning of the Eastern Han Dynasty, a large number of nomadic peoples entered the middle reaches of the Yellow River, returning farmland to pastoralism, secondary grasslands and shrubs replaced arable land, and soil erosion was relatively weakened. During the Eastern Han Dynasty, under the governance of Wang Jing, a new river channel was fixed under the control of Wang Jing.

However, this does not mean that this river that nurtured the ancestors of the Chinese nation has calmed down. More and more data show that the loss of water and soil is still serious. Although in recent years, due to the use of coal, the indiscriminate deforestation of trees in Guanzhong area has been greatly reduced. Coal has been used, and the vigorous promotion of land replacement has led to the population of Guanzhong Road that has become negative in recent years. In other words, the population of Guanzhong Road has been decreasing in recent years, and the area of ​​arable land has finally stopped expanding.

Mr. Cui Ren looked very serious: "What Lord Fang said is not bad, and the lower officials did see the flood of the river in the "Han Shu. Geography" about the recurrence of the Great River during the Emperor Dihuang period of Wang Mang."

"I did this in order to have a way to protect the prosperity of our Tang Dynasty and the fertile land of Guanzhong for three thousand miles." I shook the table in my hand and was very excited. Yes, it was time to take action. Otherwise, God knew that the reason for Guanzhong Ping was because of my arrival and not to be born in war. But the problem is that the rapid population growth is also an important part of environmental damage.

"It seems that this land replacement policy must continue. The population in Guanzhong cannot increase any further." Uncle Li looked solemn, looking at the large row of bottles placed in front of him, which contained water with sediment and sand. Uncle Li could clearly see the reality. In addition, I personally made a demonstration in front of Uncle Li, which was to use water to impact the loess dug from outside. Soon, the originally hard loess rushed out into the rapid cement.

The loess blocks covered with weeds on the surface are difficult to be dispersed. We can often see this knowledge when we were watching science and education films when we were young. But now, I have to use this method to teach the Emperor of the Tang Dynasty and the important officials of the Tang Dynasty a vivid principle of soil erosion and its mechanism of occurrence. Not only me, I also gathered a large number of officials from the Ministry of Works to give a detailed explanation to these important officials of the court who did not know any of the water conservancy.

After all, it’s not a day or two to deal with the Ministry of Works. Moreover, Yan Lide, who was originally the Minister of Works, is also very familiar with me with his younger brother. Once, he drank at his house and naturally talked about this matter. As a result, he argued that Yan Lide, the brother, thought that this young master was just a matter of worrying about the world, while Yan Liben, a great master, remained neutral and thought that what I said was reasonable, but is there any evidence? Although there are many records in ancient books, Guanzhong is currently very good, with no disasters or disasters.

In the past, disasters occurred only when the country was in a war. The country was not interested in civil affairs and did not repair water conservancy. His words also made sense. However, this young master is not so easy to convince, let alone we came from later generations, so in the end, Yan Lide agreed to second some water conservancy experts under the Ministry of Works to the Jinzou Academy to investigate the hydrological situation in the Guanzhong area. The investigation period was several years. But now, the data collected has proved my correctness and vision.
Chapter completed!