The establishment of Dujiangyan has its specific historical roots. During the Warring States Period, people suffering from war longed for the early reunification of China. Coincidentally, after Shang Yang's political reform, Qin was once famous all over the world, virtuous and virtuous, and the country became stronger and stronger. They correctly realized the special strategic position of Ba and Shu in the process of reunifying China. If you get Shu, you will get Chu, and if Chu dies, the world will merge. (Sima CuO dialect in Qin Xiang). Under this historical background, at the end of the Warring States Period, Zhao Haoqi of Qin appointed Li Bing, who was familiar with astronomy and geography and lived in seclusion, as the prefect of Shu County. After Li Bing came to power, he first made up his mind to eradicate the flood in Minjiang River, develop agriculture in western Sichuan, benefit the Chengdu Plain and create an economic foundation for Qin to unify China.
Dujiangyan construction process
In the fifty-first year of the Qin Dynasty (256 BC), Li Bing and his son, the prefect of Shu County, absorbed the experience of predecessors in water control and led the local people to build the world-famous Dujiangyan water conservancy project. Dujiangyan's master plan is to divide the Minjiang River into two branches, one of which is introduced into Chengdu Plain, which can not only divert floods and reduce disasters, but also divert water to irrigate farmland and turn harm into benefit. The main works include Yuzui diversion dike, Sha Fei weir spillway and Baojiangkou water intake.
1, construction technology of bottle mouth
First of all, Li Bing and his son invited many farmers with experience in water control, surveyed the terrain and water conditions on the spot, and decided to cut through Leiyushan to divert water. Because gunpowder had not been invented at that time, Li Bing used flint to burst the rock, and finally cut a mountain pass with a width of 20 meters, a height of 40 meters and a length of 80 meters in Leiyushan. Because its shape resembles the bottle mouth, it is named? Bottle mouth? What is the name of the stone pile separated from Leiyushan? Leave this pile? .
2. Construction technology of water-separating fish mouth
After the completion of Baokou water diversion project, although it has played a role in water diversion and irrigation, it is difficult for the river to flow into Baokou because of the high terrain in the east of the river. In order to make the Minjiang River flow eastward smoothly and maintain a certain flow rate, and give full play to the flood diversion and irrigation function of Baokou, the builder libing decided to build a diversion weir on the Minjiang River to divide the river into two streams: one downstream and the other forced into Baokou. Because the front end of the diversion weir looks like a fish head, it is called? Fish mouth? .
3. Construction technology of flying sand weir
In order to further control the amount of water flowing into the bottle mouth, play the role of flood diversion and disaster reduction, and prevent the water in the irrigation area from fluctuating and unstable, Li Bing also built a flat water tank and? Flying sand weir? The spillway ensures that there is no disaster in Neijiang. There is a bend in front of the spillway, and the river forms a circulation. When the river exceeds the crest of the weir, the mud and stones carried by the flood will flow into the outer river, so as not to block the Neijiang and Baokoukou waterways, hence the name? Flying sand weir? .
In order to observe and control the water quantity in Neijiang, Li Bing carved three stone statues and put them into the water. Low tide does not flood feet, but shoulders? To determine the water level. Stone horses are also chiseled and placed in the middle of the river as a standard for scouring the beach when the water quantity is the least every year.
Under the leadership of Li Bing, people overcame many difficulties, and after eight years of hard work, Dujiangyan was finally built as a historical project.