Merton nodded and asked again, "almost all rivers in Guanzhong are muddy! But which river is the most serious? The more serious it is, the more problems can be exposed."


    "Weihe River!"


    Duan Lun said hoarsely.


    This time, all the courtiers were silent. This time, it was not dark under the light, but blind. The Weihe river flowed from the edge of Chang''an city every day. It was their most familiar river. Everyone knew how turbid the water of the Weihe River was, but they never saw it.


    "When I entered the Tai Chi hall for the first time, when I saw that the officials and generals were divided into one side, a word immediately appeared in my mind, which was clear." Merton sighed.


    "Clear? What''s the meaning of this?" Cheng Yaojin asked, but he had heard the word for the first time.


    Merton said: "Jinghe River is a tributary of Weihe River. However, the water of Jinghe River is extremely clear, and the water of Weihe River is very turbid. Therefore, at the intersection of Jinghe River and Weihe River, there is a wonder. The river water is half turbid and half clear, which lasts for several miles."


    The courtiers could not help blushing. This "spectacle" is very ironic.


    "So, the sediment of Weihe River flows from other tributaries above Jinghe River," Cheng Yaojin thought.


    Merton nodded: "then the question is, why is there so much sediment in the upper reaches of the Weihe River? If the sediment problem of the Weihe River can be solved, the problems of other rivers will be solved."


    Li Shimin took a deep breath and said, "take the map of Guanzhong."


    A huge map of Guanzhong is fully unfolded in Taiji hall. Li Shimin looks at the watershed map of Weihe River with a gloomy face.


    "Black water, Ba water, lacquer water, thousand water..." Li Shimin looked more and more ugly. The whole area of Weihe River was too large.


    "According to this analysis, the sediment source of the Yellow River is in this area." Li Shimin stretched out his hand and roughly drew the area of the later Loess Plateau.


    All the courtiers nodded involuntarily, suddenly their faces coagulated, and their eyes involuntarily floated to several ministers at the forefront of the court, especially the eldest sun Wuji.


    Guanzhong, especially the Loess Plateau, is the sphere of influence of Guanlong group, and changsun Wuji is the representative of Guanlong group in the dynasty.


    Merton still nodded imperceptibly and said, "yes, now we need to understand why the soil here is lost so seriously."


    This time, everyone didn''t answer. Qin Qiong wanted to dissuade Merton, but she was stopped by Cheng Yaojin. She opened her bow without turning back. Now that she has reached this point, there is nothing to say. She retreated at this time, which makes the emperor unhappy.


    Duan Lun took a look at his eldest son Wuji and said, "this place is full of loess. The soil is loose. Once it meets rain, it will wash away the soil."


    Merton solemnly nodded and saw two dense pots of potted plants outside the Tai Chi hall. He had an idea and said, "this phenomenon is called soil erosion by the Mohists. If you want to retain sediment, you must understand how soil erosion is formed. If we don''t do an experiment."


    "Test?"


    People are familiar with this word. The Mohist experimental field is famous in Chang''an city.


    Merton went to the potted plant, looked at the huge potted plant and moved it hard, but the potted plant didn''t move. At present, he was embarrassed and said to Xi Junmai, "brother Xi, please do me a favor and move the potted plant on the right to the outside in the rain."


    When Xi Jun bought a meal, he had a headache one by one. You were too brave to move things in the Tai Chi hall. You couldn''t help looking at Li Shimin.


    "Move!" Li Shimin waved his hand.


    Xi Jun bought the order and came forward with a little force. Hua effortlessly moved the potted plants to the rain outside.


    "Brother Xi, break this basin again and move it out in the rain."


    Xi Jun took a swipe when he bought the cheek. Merton didn''t go to court several times. Naturally, he didn''t know that these two plates of potted plants were Li Shimin''s favorites, and Merton was bold enough to destroy them.


    "Broken! If we can solve the problem of the Yellow River, a potted plant is not enough." Li Shimin endured heartache and waved his hand.


    Xi Jun took orders when he bought it. With a click of his teeth, he broke the potted plants and moved them to the rain.


    It rained heavily outside the Tai Chi hall. Soon, the bottom basin of the potted plants was covered with water. Merton asked Xi Junmai to move it back to the hall.


    "Your Majesty, look!" Merton pointed to the rain channel in two potted plants.


    Li Shimin looked at his beloved potted plant being ruined by Merton. He couldn''t help but look blue and red. It took a long time to calm down.


    Fortunately, Li Shimin was Mingjun. He restrained his anger and came to the potted plant. He saw the intact potted plant. The rain under the bottom basin was very clear. The broken basin was not covered by leaves. The rain directly washed the soil, and the whole basin was full of muddy muddy water.


    Merton said: "Wei Chen once looked up history and found that there were dense forests in Guanzhong during the pre-Qin period, but at that time, the Weihe River was extremely clear. Only because a large number of forests were cut down and reclaimed into land, so that the loess was directly exposed, this would cause soil loss, just like the broken pot plant in front of him."


    Many ministers nodded. In this way, it is indeed the reason for deforestation.


    Merton sighed: "In fact, what people don''t know is that not only the soil but also the fertility of the land will be lost along with the rain. In the long run, the fertility of the farmland will be lost, and the land in Guanzhong will become more and more barren. At that time, the grain production will be reduced, and the people''s living income will not be able to make ends meet. Then the people will reclaim more land in order to survive, and then the fertility of the land will be reduced Then washed away by the rain, it will be a vicious circle.


    Moreover, Wei Chen heard that the upper reaches of the Weihe River have been washed out with many deep gaps. If they are not treated, the upper reaches of the Weihe River will become thousands of gullies and fragmented year after year, just like cracked pottery. At that time, the once fertile pass will become a history. "


    Merton finished in one breath, and the whole Tai Chi hall was as silent as death.


    Guanzhong is the foundation of the Tang Dynasty. It can be said that it is the dragon vein of the Tang Dynasty. If it comes to that time, I''m afraid the foundation of Guanzhong will be destroyed.


    Merton thought of the fragmented situation of the Loess Plateau in later generations, just like a heart knife. If he could alleviate the soil erosion of the Loess Plateau in this era, maybe everything would be in time.


    "So the people in Guanzhong open up wasteland and farm land is the ultimate reason for the formation of sediment in the Yellow River?" Li Shimin said bitterly.


    Merton nodded solemnly and said, "Buddhism pays attention to cause and effect, but there is some truth. In fact, many human bitter fruits are planted by ourselves."