Before the electrification revolution, there was no man-made object that could produce profits and benefits comparable to Dujiangyan, it is the only infrastructure that has been in normal use for more than 2,000 years, and every year because of Dujiangyan's contribution, the Chengdu Plain can produce food to feed millions of people, eliminating thousands of floods and droughts.

Dujiangyan water conservancy project is around 257 B.C. Qin Shu County Taishou Li Bing and his son led the people to build, he adopted the water conservancy diversion scheme according to local conditions, cleverly solved the problem of water balance in the Chengdu Plain drought and flood, more respectable is that after more than 2000 years of construction, Dujiangyan is still benefiting the descendants of Yan and Huang. According to the most conservative estimates, the benefits produced by Dujiangyan have at least cumulatively fed 200 million people, and the contribution to the stability of grain prices and prices in ancient society is at least equivalent to the cumulative effect of 5 billion guan, and the other indirect effects and benefits are no less than 30 billion guan. Is there a project of the same scale in ancient and modern China and abroad that can be compared with this project?

The Dujiangyan Water Conservancy Project has three main components, namely Yuzui, Feishayan and Baohuakou. Yuzui divides the Minjiang River into the inner river and the outer river, because the inner river channel is deep and narrow, the outer river channel is shallow and wide, in the dry season, there will be sixty percent of the water into the inner river to irrigate the Chengdu plain, and in the flood season, sixty percent of the water is discharged from the outer river, which is the "four or six water"; When the flood is very large, the bottleneck at the mouth of the treasure bottle will be limited in the process of flowing into the inner river, and as soon as the water level is higher than the top of the flying sand weir, it will carry sand and gravel from the top of the weir and the water distribution tank into the outer river, which plays the role of flood discharge; The flying sand weir is located at the bend, and the centrifugal force can be used to throw sand and gravel into the outer river, reducing the sediment deposition in the inner river, as long as the dredging is done regularly during the dry season. Only a good understanding of the local hydrology and geography can make such a clever design, and the Chengdu Plain is thus rich.

In the early days of Li Bing's construction of the weir, the name of Dujiangyan was called "Maoyan", this is because the Yulei Mountain next to Dujiangyan, the Qin and Han dynasties used to be called "Maoshan", and at that time, the main inhabitants around Dujiangyan were the Qiang people, they called the weir "Wei", so Dujiangyan was called "Maoyan". During the Shu and Han dynasties of the Three Kingdoms, Dujiangyan area set up Du'an County, named after the county, Dujiangyan was called "Du'an Yan". At the same time, it is also called "Golden Embankment", which is to highlight the role of the fish mouth diversion embankment, and use the embankment as the name of the weir. In the Tang Dynasty, Dujiangyan was renamed "Weir". Because the materials and methods used to build embankments at that time were mainly "breaking bamboo as a cage, with a circle diameter of three feet, and using the stone to solid, tired and flooded with water", that is, using a bamboo cage to load the stone, which is called "the tail of the tree".

It was not until the Song Dynasty, in the history of the Song Dynasty, that the word Dujiangyan was mentioned for the first time, "Yongkang army ruled Dujiangyan for many years, and the cage stone snake broke the river to curb the water, so as to irrigate several county fields." Regarding the origin of the name Dujiang, "Shushui Kao" said: "Fuhe, a Chengdu River, has two sources, namely Pijiang River and Liujiang River. Liujiang is another name for the river, the Fu River on the Chengdu Plain is the Pijiang River, the South River is the Jianjiang River, and their upstream is the Baitiao River and the Zouma River that divide the Neijiang River in Dujiangyan. "Gu Di Zhi" said: "Dujiang is the Chengdu River". Since the beginning of this dynasty, the project of the entire Dujiangyan water conservancy system has been summarized and called Dujiangyan, which has more accurately represented the entire water conservancy engineering system and has been used to this day.

"Guess how much irrigation area Dujiangyan has now? How much is the area of the Chengdu Plain? What is the maximum irrigated area in the future? What is the maximum value of gross output of food and cash crops? I guessed correctly that I personally awarded him 1% of the core parent company of Chenji Group Company, which is the shares of this academy. If no one guesses the answers to these four questions, choose the closest person to serve as the supervisor of our newly established Chengdu Fu Lu Chenji Branch for a period of time. You can rush to answer, and the time limit is 2 minutes. After Li Ji finished speaking obscenely, he began to look at the timer.

In order to answer the question correctly, the people who heard the good news began to rack their brains to recall the details of the national resource development plan layout meeting a long time ago. It is clear to everyone that a 1% stake in the core company will definitely be worth more than the market value of Huaxia Petroleum in 2012 in 60 years. As for going to the country of abundance to be a supervisor, it is a beneficial errand, not only with generous allowances and rewards, but also for those who go to the branch to occupy a little more. More importantly, the work will be much easier than the headquarters, and the extra time can be used to meet the preparation and needs of life events.

Zhao Shouzhong replied that "the existing irrigation area is 200,000 hectares, with a total area of 700,000 hectares and a maximum irrigation area of 670,000 hectares. The total output value of agriculture can reach 30 billion yuan. ”

"How do you know that these numbers are unfounded?" Liu Xin reacted.

"Anything else you haven't answered?" Li Ji asked.

"I know that the Dujiangyan system before the reconstruction and expansion can only irrigate 3 million acres of paddy fields, that is, 200,000 hectares, but the area of the Chengdu Plain is not 700,000 hectares, but 2.29 million hectares, 700,000 hectares of knowledge Tuojiang, Minjiang alluvial fan plain, according to the Chenji money is not accurate enough, because the Chenji money is mainly the purchase of general and high-grade commodities, not the settlement currency of bulk commodities, although from the purchasing power parity of basic consumer goods, 10 yuan Chenji money is about equal to 1 copper coin, But there are large fluctuations and errors. According to our productivity, the grain output of the whole Sichuan should reach half of the 30 billion kilograms before coming here, that is, 15 billion yuan, and after deep processing and the output value of cash crops, it should be able to reach 20 billion chenji. However, the moisture of this number is still too large. ”

"Sun Chang is right, it's him, when the time comes, there are still people who take advantage of him, and he deserves to be the dean of the College of Agriculture." Li Ji patted Sun Chang on the shoulder and said.

"Our new products, cement and soil fertilizers for impermeable irrigation, can be used to make a big difference. When Sun Chang went to Chengdu Mansion, he could buy a large amount of wasteland and relatively poor cheap land, and by the way, he bought these lands and hills that I marked the key marks on, these are all treasures in the future. It is possible to build factories and special seedling bases. ”

Qian Jin suddenly remembered that the new modern cotton textile machinery he asked students to design was facing the dilemma of no raw materials, and began to calculate the various data of the textile machinery. "Lao Sun, can you promote the fine staple cotton brought last year in the northern part of the Sichuan Basin where the hydrothermal conditions are more suitable, although many of the modern crops we brought are high-yield, disease-resistant and pest-resistant varieties improved by genetic technology, but they can't stand the hybridization and assimilation with the same ancient species, so we also need to use a large number of machinery to open up enough seedlings and seedlings that are not easy to be affected to avoid the assimilation of local ancient species. The quality and quantity of the semi-manpower transitional model of agricultural machinery we produce are not enough to replace all the existing models of feudal agricultural labor. Therefore, the production and marketing of seeds is a key task. ”