Only Dujiangyan, a famous water conservancy project characterized by dam-free water diversion, can survive for a long time in China, playing an increasingly important role and showing its incredible water conservancy concept to the world. In 2000, Dujiangyan in China was listed as a "World Cultural Heritage" by UNESCO. It is a national key cultural relic protection unit, a national scenic spot and a national AAAAA tourist attraction.
Dujiangyan is located in the west of Dujiangyan City, Chengdu, Sichuan Province, on the Minjiang River in the west of Chengdu Plain. It was built in the last years of Zhao Haoqi in the Qin Dynasty (about 256 BC-25 BC1year). It is a large-scale water conservancy project organized and built by Li Bing and his son, the county magistrate of Qin Shu, on the basis of excavating the turtle spirits of predecessors. It is composed of a fish mouth, a flying sand weir and a bottle mouth, which has been playing the role of flood control and irrigation for more than 2000 years. Chengdu Plain has become a "land of abundance" with thousands of miles of floods and droughts. Up to now, the irrigation area has reached more than 30 counties and cities, covering an area of nearly 10 million mu. It is the oldest, only preserved and still in use in the world. It is characterized by water diversion without dam, which embodies the diligence, courage and wisdom of the ancient working people in China.
Chengdu Plain, known as "Land of Abundance", was a place where floods and droughts were very serious in ancient times. The lamentation and tragic situation of "until two rulers crowded past in the foggy age of this area" and "man or fish became a turtle" in Li Bai's Shu Dao Nan is a true portrayal of that era. This situation is caused by the harsh natural conditions in Minjiang River and Chengdu Plain.
Minjiang River is the largest tributary of the upper reaches of the Yangtze River. The Minjiang River runs out of the Minshan Mountains and goes south from the west side of Chengdu Plain. For the whole Chengdu Plain, it is an authentic river hanging on the ground, hanging miserably. The overall topography of Chengdu Plain is from Minjiang River to Leiyu Mountain, and it is inclined to the southeast with a great slope. Dujiangyan is 50 kilometers away from Chengdu, but the drop is 273 meters ... In ancient times, whenever the Minjiang River flooded, the Chengdu Plain was a Wang Yang. Once there is drought, it is thousands of miles away and there is no harvest. The flood of Minjiang River has long harmed Xichuan, devoured fertile land and infringed on people's livelihood, which has become a major obstacle to the survival and development of ancient Shu.
During the Warring States Period, people suffering from war longed for the early reunification of China. After Shang Yang's political reform, Qin became more and more prosperous. They fully realized the special strategic position of Ba and Shu in the process of reunifying China. Sima Cuo, the prime minister of Qin Dynasty, said, "If you get Shu, you will get Chu, and if Chu dies, the world will be merged.". 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 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.
In the thirty-first year of Qin Zhaowang (276 BC), after careful consideration, Qin Zhaowang appointed Li Bing as the prefect of Shu County. In the third year (274 BC), Li Bing began to build Dujiangyan. After careful investigation of the upstream or downstream of the river for many times, Li Bing decided to build Dujiangyan's first hub with Yuzui diversion dike, Baokou mouth and Feisha weir. The three major projects echo from beginning to end, trinity, natural way and harmony between man and nature, which make dikes, water diversion, flood discharge, sediment discharge and flow control interdependent and ensure the full play of comprehensive benefits of flood control, irrigation, water transportation and social water use. Ditches as dense as cobwebs are the endless meridians and veins of agriculture in Shu.
Dujiangyan is also outstanding in that such a huge water conservancy project has not built a dam. Li Bing didn't deliberately conquer and transform nature, but followed the principle of conforming to nature and imitating nature. He made use of the mountain, terrain and water potential to guide the situation and adapt it to the times, achieving the effects of automatic diversion, automatic sediment discharge and gravity irrigation, and achieving a high degree of coordination and unity among people, land and water.
In 256 BC, Li Bing led migrant workers for eighteen years and completed this unparalleled water conservancy project. The "dragon" of Minjiang River was finally subdued. Li Bing and the water conservancy workers at that time were very wise. More than two thousand years ago, they knew how to live in harmony with nature. Even today, more than 2000 years later, Dujiangyan is still a model of harmonious coexistence between man and nature. It has written the most brilliant chapter in the history of water conservancy in the world, deservedly became the crystallization of the industrious wisdom of the ancient working people in China, and is an epoch-making masterpiece of Chinese culture.
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.
0 1 bottleneck construction technology
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 is similar to that of the bottle mouth, it is named "Treasure Bottle Mouth", and the stone pile separated from Leiyushan is called "Remaining Pile".
The reason for repairing the bottle mouth is that only by opening Leiyushan and letting the water of Minjiang River flow eastward smoothly can the flow of the river in the west be reduced, so that the river in the west will no longer flood, and at the same time, the drought in the east can be alleviated, so that the surging river can flow into the arid area and irrigate the fertile fields there. This is the key link of flood control and the first step of Dujiangyan project.
Construction technology of 02 water distribution 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 east of the Yangtze 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, Li Bing 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".
The completion of the fish mouth divides the upstream river into two parts: the west side is called Waijiang, which flows down the Minjiang River in the rain; The east is called Neijiang, which flows into the bottle mouth. Because the Neijiang River is narrow and deep, and the outer river is wide and shallow, the water level is low in the dry season, and 60% of the river water flows into the Neijiang River with a low riverbed, which ensures the production and living water in Chengdu Plain. When the flood came, because of the high water level, most of the river water was discharged from the wide outer river. This design of automatic distribution of water inside and outside the river channel is called "four-six water diversion".
Construction technology of 03 flying sand weir
In order to further control the amount of water flowing into Baokou, 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 trough and a "flying sand weir" spillway at the tail of the Yuzui diversion levee near Baokou to divert the flood, so as to ensure 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, mud and stones carried by the flood will flow into the outer river.
The flying sand weir is made of pebbles in bamboo cages, and the top of the weir is at a suitable height, which plays a role in regulating water quantity. When the water level in Neijiang is too high, the flood will overflow the flying sand weir and flow into the outer river through the flat sink, so that the water entering the bottle mouth will not be too large, and the Neijiang irrigation area will be protected from floods; At the same time, the aquatic products that crossed the Sha Fei weir and flowed into Waijiang created a swimming vortex. Due to centrifugation, mud and even boulders will be thrown over the Sha Fei weir, which can effectively reduce the sediment deposition around the bottle mouth.
In order to observe and control the water quantity in Neijiang, Li Bing carved the portraits of three stone piles and put them into the water 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.
After the completion of Dujiangyan, the Bashu land, which was originally unstable in floods and droughts, experienced a bumper harvest of "fertile fields, floods and droughts follow people, and there is no shortage." According to "Historical Records of Hequ", "Shu shou ice chisels away from cymbals to prevent the harm of foam water; The second river across Chengdu. This canal can be used for boating, and the rest is used for irrigation and soaking, which is beneficial to the people. As for what happened, it is often the canal used to irrigate the fields, in trillions, but it is not enough. " With unprecedented economic prosperity and well-fed people, Sichuan is known as the "land of abundance".
It is precisely because of the rich strategic rear of Shu County that Qin became the most powerful vassal state among the Seven Heroes in the Warring States Period. According to the records of Huayang National Records and Shu Records, in 223 BC, the generals of the State of Qin, Wang Jian and Wu Meng, "led hundreds of thousands of people in Bashu, welcomed guests with 10,000 ships of 6 million tons, conquered Chu by floating rivers, and took Shang Lu as the county in central Guizhou", and unified the whole country two years later. As the backing of the unified war, Dujiangyan is the real hero behind Shu County.
In the following years, thanks to the irrigation of Sichuan by Dujiangyan, the rich land of abundance not only raised many children of Bashu, but also helped the whole country with famine many times, three times in the Han Dynasty alone. After the outbreak of War of Resistance against Japanese Aggression, Sichuan became the rear area of China's Anti-Japanese War, and Dujiangyan was the rear area of the rear area. 1943, when US Vice President Wallace visited Dujiangyan accompanied by General Feng Yuxiang, he said excitedly, "Dujiangyan is the pride of China, which has played a supporting role in our victory over fascism."
After the victory of the Anti-Japanese War, Xinmin Daily published an editorial "Don't forget Sichuan". The article wrote: "Sichuan's contribution to the war of resistance is special. During the Anti-Japanese War, Sichuan not only became the central government, but also accommodated all the administrative organs in the country and supported the officials and people who did not want to be slaves. As far as supporting the Anti-Japanese War is concerned, Sichuan has the heaviest burden, contributed money and always advocated the first. Without Sichuan, we can't imagine why the Anti-Japanese War lasted so long ... "
Dujiangyan irrigation and water content are not only reflected in water conservancy. Dujiangyan, as a land of abundance, not only created a land of abundance, but also gave birth to Bashu civilization, constantly enriching the culture of abundance. As Yu said, "Dujiangyan is the key to understanding Chinese civilization." Dujiangyan is not only the cradle of Chengdu's urban development, the lifeline of Chengdu's economic and social development, but also the driving force of the civilized center in the upper reaches of the Yangtze River. Without Dujiangyan, the Bashu civilization and the Yangtze River civilization could not have today's glory, and the Chinese civilization would be eclipsed by the lack of the important support of the Yangtze River civilization.
Dujiangyan irrigated Taoism, which is the material hotbed of Taoism. In addition to geographical and ideological factors, the richness of the land of abundance created by Dujiangyan provides material guarantee for believers to pay "five buckets of rice". The establishment of Dujiangyan directly influenced the emergence of Taoism. The profound influence of Taoism on China is actually Dujiangyan's irrigation of politics, philosophy, science and technology, culture and folk customs in China for more than a thousand years.
Dujiangyan irrigation technology is the soul of leading river engineering technology. Since the Han Dynasty, Dujiangyan's unique water control concept and engineering technology, such as "deep scouring beach, low weir", "cutting corners when encountering the bay", "building pebbles" and "sheepfold", have been widely used in flood control and emergency rescue of the Yellow River, Huaihe River and Pearl River, and Dujiangyan irrigates the land of China with its unique technology.
Dujiangyan irrigated the culture and created a national cultural elite. Dujiangyan Irrigation District, nourished and quilted by Dujiangyan, breeds a group of cultural elites who shocked the world and influenced the times in every era, such as Sima Xiangru and Yang Xiong in Han Dynasty, Changqu in Jin Dynasty, Chen Ziang and Li Bai in Tang Dynasty, Su Xun, Su Shi and Su Zhe in Song Dynasty, Yang Shengan in Ming Dynasty, Li Diaoyuan in Qing Dynasty, Xie Wuliang, Zhang Daqian, Guo Moruo, Ba Jin and Li Renjie in modern times. These cultural giants who grew up drinking Dujiangyan water all influenced China with their excellent works and great personalities.
In addition to Dujiangyan, Li Bing also presided over the construction of other water conservancy projects in the Minjiang River Basin. He built an artificial river-Mayang River on the main stream of Minjiang River. In order to straighten out the navigation channel and improve it, Li Bing also opened stone beaches such as Yuan Lei, Yanguan and Lan Bing in Nan 'an (now Leshan) and Bodao (now Yibin), and also built Wenjing River (now Xihe River in chongzhou city), Mubai River (now Nanhe River in Qionglai), Luoshui River (now Shiting River) and Mianshui (now Mianshui).
During Li Bing's tenure as Shu Shou, he "knew the water vein and connected Guangdu (now Shuangliu, Chengdu) salt well, so Shu was full of health". Li Bing created the method of drilling wells to cook salt with brine, which ended the original situation of salt making in Bashu, and this is also the earliest record of drilling wells to cook salt in China historical records. Li Bing also built seven bridges in Chengdu, namely Chongzhi Bridge, Shicheng Bridge, Jiangqiao Bridge, Wan Li Bridge, Yili Bridge, Changsheng Bridge and Yongping Bridge.
In about 235 BC, when Li Bing was building water conservancy projects in Luoshui Town, Shifang, Sichuan, he died of overwork and was buried in Zhangshan Mountain near Luoshui. For more than two thousand years, people in Sichuan have always regarded Li Bing as the "master of Sichuan". The "Sichuan Main Temple" built in memory of him is spread all over Sichuan, especially the Erwang Temple on the Dujiangyan River, which is the most famous and sacred, showing the love and admiration of Shu people for Li Bing.
The Dujiangyan water conservancy project built by Li Bing occupies a glorious page not only in the history of water conservancy in China, but also in the history of water conservancy in the world. Its long history is world-famous, and its complete design is amazing! Many water conservancy projects were built in ancient China, among which Shaopi, Zhangshui Canal and Zheng Guoqu were quite famous, but they were abandoned one after another. Dujiangyan, founded by Li Bing, has been enduring for a long time, and still plays a variety of functions such as flood control, irrigation and transportation.
1955, when Guo Moruo arrived in guanxian, he wrote an inscription: "Li Bing dug away from the pile and dug a salt well, which not only benefited Shu people, but was actually an outstanding engineering and technical expert in China two thousand years ago." Li Bing's scientific spirit of devoting himself to building a clean government, respecting nature and taking the lead in setting an example is not only the embodiment of China's wisdom in China's excellent traditional culture, but also has irreplaceable value and practical significance.