1. Reasons for salt digging in the well: Sichuan lacks salt. Sichuan is located inland, not close to the sea and ponds. Therefore, it does not produce sea salt and pond salt. At the same time, no salt wells were dug and no salt was produced. There is Daning Salt Spring in East Sichuan and Zhongba in Zhongxian County. The underground (brackish water) became the salt-making base in Pakistan and Sichuan at that time, which supplied people's food demand. Daning salt spring is also called? Longchi? The hunter who was chased by the white deer found it, hence the name? White deer brings spring? , located at the foot of Baoyuan Mountain in Wuxi.
In ancient times, brine? Out of the ravine? The spring is very abundant, and if the potential drops, it will lead to brine. Because it is convenient to take brine, it originated very early, and the production of salt flourished in Shang Dynasty. Daning Salt Spring in Song Dynasty has become a famous salt-producing area in Sichuan, showing a prosperous scene. Therefore, it has attracted the attention of poets and literati. Lu You, a patriotic poet in the Southern Song Dynasty, wrote in Notes on the Old Xuegong (Volume 5):? Shu eats well salt, such as Daning, and it is still a big cave. ? Song? Ma Duanlin's General Examination of Literature (Volume 16) said:? The salt well of Daning Fushun (now Zigong)? The elimination well in Changning is also a big well. ? The same document (Volume18 (ix)) also states that Daning supervises the production of salt. The benefits of a spring are enough to run around? . ? East of Mo, a land and water meet? (ibid., document, vol. 167).
Daning Salt Spring is located in the east of Sichuan, near the Yangtze River. It can be seen that Sichuan was in an important position both economically and socially at that time. At the beginning of the Northern Song Dynasty, in the year of Emperor Taizong's reign (988), the salt production in Sichuan dropped sharply, and the output was not enough to sell. The salt shortage in western Sichuan caused a great salt shortage, which made businessmen sell Daning salt to Chengdu and other places.
Daning salt spring is a natural water source without labor. The salinity of salt water varies with natural seasons and is influenced by atmospheric and surface rain. Brine is salty in winter and early spring, but salty in summer and autumn rainy season. The annual production time is about 6 ~ 8 months.
Due to the long history, the output of Daning salt and Zhongba salt in eastern Sichuan could not be inquired during the period of Qin's reunification with Bashu, so it is unknown today. In the early Song Dynasty, Daning Spring was in the heyday of brine production, ranking among the best in Sichuan, such as Song Shenzong Xining Middle School (1069- 1077), with an annual output of salt? More than 4 million Jin? . Taking this as an example, the salt consumption of Sichuan people in Bashu period was calculated. Of course, due to the progress of society and the development of productive forces, the output of spring salt has also changed successively, that is, the salt output in the early Song Dynasty can not fully represent the salt output in the Bashu period, but it can be seen that.
After Qin destroyed Bashu, Sichuan was in a period of peace and stability without a major war. Shiping Dow? . At the same time, due to a large number of immigrants entering Sichuan, the social economy developed rapidly, which greatly stimulated the population growth. So after the Qin Dynasty destroyed Pakistan, the population increased. 1600000? About. It can be calculated here that before salt wells were drilled in Sichuan, according to the supply and demand of salt in Daning, if Daning produced 4 million Jin of salt a year and the population of Sichuan was 1.6 million, the annual salt consumption per capita was 2.5 Jin.
People are suffering from light food because of the shortage of salt. Even if the pool salt is shipped from Shanxi, it is difficult for ordinary people to buy it because of the geographical conditions in Sichuan, the distance is long and the price of salt is high.
Second, the first salt well in China was dug in ancient times. Sichuan is vast and sparsely populated, with frequent floods and droughts and backward economy. Out of the way? Land. Li Bing developed it when Qin ruled Sichuan. Out of the way? Made a significant contribution. The completion of Dujiangyan has turned the western Sichuan region, which was originally seriously affected by floods and droughts, into? Woye Li Qian? In the rice barn, people can eat their fill. However, Sichuan people have long been short of salt and suffer from a light diet. Therefore, Li Bing opened another salt well, and made salt by extracting brine to meet the people's food demand, thus alleviating the people's pain of lack of salt and food. Since then, salt wells have mushroomed in vast areas of Sichuan. Salt is not only self-sufficient, but also surplus. The remaining salt is also exported to parts of Yunnan, Guizhou and other provinces. Sichuan ancestors began to knot, ending their complete dependence on natural salt springs. Saltus Tong? Get the history of salt. Created a new chapter in the history of manual shaft sinking, brine mining and salt making.
There is a dispute in the field of salt history about Li Bing's digging a salt well. There are three main opinions:
One view is that the digging of salt wells is accidental, that is, salt water appears when people drill wells, so it is named salt wells; Another view is that the population of Sichuan is increasing and the demand for salt is large. Daning salt, nitrate salt or pond salt from afar are not enough. So drilling wells in Sichuan to find salt; Another view is that Dujiangyan project is closely related to salt well excavation. We believe that it is no accident that the second opinion and the third opinion are combined into one, that is, Li Bing digs salt wells to meet the people's urgent need for salt. At the same time, there is a certain internal relationship between sinking and water control.
In short, as far as the digging of Guangdu Salt Well is concerned, it is not an isolated and accidental phenomenon, but closely related to the geological conditions and digging technical conditions in this area, mainly in the following three aspects.
1. The rich underground brine in western Sichuan Plain provides material resources for salt well excavation. According to the results of geological exploration, there are rich mineral resources of brine, mirabilite and gypsum in Tertiary and Cretaceous strata of western Sichuan depression in Chengdu Plain, in which the salt content of brine is about100g/L. In some areas, the brine layer is shallow and the depth is 20 ~ 30m. The unique brine resources provided important material conditions for the first salt well in China.
2. Li Bing discovered the underground brine from the salt well. Li Bing entered Sichuan on time, built water conservancy projects, dug piles, avoided the harm of foam water, crossed the middle of Erhe River and Chengdu, diverted water to irrigate fertile fields, and made the western Sichuan plain? Woye Li Qian? Become a famous land of abundance at home and abroad. Dujiangyan project is huge and magnificent. In the process of construction, the implementation scheme was adopted. Cut corners in case of bending, deep scouring the beach and low weir? Adopt effective and practical technical measures such as dredging and embankment construction. For this, in the water? Cut corners? Tan Tao? Dike? In the process of excavation and excavation, shallow underground brine resources are exposed, such as Li Bing's new discovery of underground brine in Qingyijiang dredging project, which is clearly recorded in historical records.
According to Jinchangqu "Huayang National Records? Shu Zhiyun: Is there a stone beach in Nan 'an County (now Leshan and Jiajiang in Sichuan) and Qingyijiang, also known as Ink? Salt irrigation? , the author Bingping. Northern Wei Daoyuan's Notes on Water Classics also said: River water? Is there a beach of hanging irrigation in the southeast and west of Nan 'an County? Daily salt irrigation, Li Bingping. ? ? Salt irrigation? That is, natural salt springs on the surface and underground brine outcrops. However, ships often break down because of its stone beach in Qingyi River, which hinders the smooth flow of the river and makes navigation difficult. Therefore, Li Bing regulated the waterway and excavated beach stones in the river to facilitate navigation and water diversion. Because of this, although there are salt springs here, this beach has been leveled, so it is named Salt Irrigation Beach, that is, Salt Spring Beach. Li Bing, a pioneer in digging salt wells, discovered groundwater by harnessing water.
3. Li Bing? Do you know the water vein? Li Bing, who dug salt wells, was a famous expert in water conservancy and sinking engineering during the Warring States Period. He is knowledgeable and proficient in astronomy and geography? Do you know the water vein? Led the people to successfully dig the first salt well in China.
In the process of water control, Li Bing discovered a new salt spring, that is, underground brine flowed out of the ground, which sent a message to people, suggesting that western Sichuan is rich in brine resources. Therefore, it gave an important revelation to Li Bing, the host and leader of water control at that time. On the ground, the completion of Dujiangyan has gained huge water resources, turning the Chengdu Plain, where floods and droughts frequently occur, into a granary. At the same time, there are precious salt water resources buried underground, which can be used to dig wells and fry salt with brine to alleviate the urgent need of salt shortage and light food in Shu.
So, Bing. Do you know the water vein? That is, according to the geological conditions, investigate the distribution law of underground brine, personally wade through mountains and rivers, explore rocks and find valleys, and understand brine veins. According to? Depending on the mountain, you can drill wells, and the ditches are different. According to our folk experience, we finally found a shallow underground brine layer in Chengdu and Shuangliu, western Sichuan. At the same time, he creatively applied the central plains drilling technology and popularized the use of iron tools, and purposefully dug the first salt well in China? Guangdu salt well.
The appearance of Guangdu Salt Well opened the prelude of salt production in China Well. Since then, salt wells have developed rapidly in the whole province, from three counties in the Qin Dynasty to 18 counties in the Han Dynasty.
Three, about the early production mode of salt well Guangdu salt well is the first salt well dug in China. Because of the long history, this salt well has not been preserved, so the shape, shaft structure, ground facilities and production mode of the salt well are unknown.
However, we have obtained evidence from the image of Han Dynasty well salt production portrait brick unearthed in Sichuan. With vivid, delicate and vivid artistic image, the portrait reproduces the technological process of well salt production in Han Dynasty, which provides physical evidence for studying the early sinking engineering technology in Sichuan.
The portrait brick shows a salt well near the foot of the mountain on the left with the background of mountain forest, deer abandoning and jumping and chopping wood. There is a four-column double-layer building frame (i.e. derrick) on the wellhead ground, and a stove is set on the right side of the salt well to make salt. As can be seen from the image, the salt well is circular, with a wellhead diameter of about 2 meters. According to the buried condition of underground brine layer in western Sichuan, the shallowest depth of the salt well is estimated to be more than 20 meters. Obviously, its well shape is a new type of salt well designed by drawing lessons from the advantages of ancient wells in the Warring States period.
It can also be seen from the image that the four-column, two-story brine extraction building looks like a pagoda with a slightly narrow top and a wide bottom. According to the height of people, the total height of the building is about 8 meters. At the top of the building frame is a pointed ceiling, which is obviously designed to keep out rain, dew and sunshine. A certain pulley is installed on the lower cross bar, and a bittern collecting rope is tied to the pulley, and bittern collecting barrels are hung at both ends of the rope. On the upper and lower floors, four people work in two groups, alternately pulling rope elements, coordinating actions, extracting brine, then pouring it into wooden containers and transporting it to a salt furnace with bamboo poles for frying. Although it is not labor-saving, it changes the direction of force, reduces the labor load and improves the work efficiency. It is the application and development of pulley water lifting principle in the Central Plains.
To sum up: Li Bing was an outstanding expert in sinking engineering and water conservancy during the Warring States Period. He was punctual in Sichuan and did many good things for the people of Sichuan. But there are two main achievements left today: the construction of Dujiangyan project and the excavation of Guangdu salt well. Because of the rich underground brine in western Sichuan, it has laid a solid material foundation for drilling salt wells. In the process of water control, Li Bing discovered shallow underground brine, which was a pioneer in digging salt wells. At the same time, he is knowledgeable, proficient in astronomy and geography, and good at? Do you know the water vein? He personally led the people to creatively apply Zhongyuan drilling technology in Chengdu and Shuangliu, western Sichuan, and successfully dug the first Guangdu salt well in China, creating a precedent for salt production in China.