PS: The first update, yesterday was not in a good state, checked a lot of information, and the second update was not written, sorry.

In the fields outside Huangzhuang, the canals have been dug at this time, and many large waterwheels can be seen in the distance.

"Your Majesty, drought and flood protection is irrigation, we take a large pond to store water, several Huangzhuang to build a large pond, each Huangzhuang to build a small pond. In times of drought, the pond can be sustained for a period of time. At the same time, irrigation ditches should be built, supplemented by cylinder cars and overturned cars. In the event of a flood, it can be drained by a rollover. Xu Guangqi introduced Zhu Youxiao all the way.

The cylinder cart is also the kind of large round water wheel, which is constantly rotating under the impact of the water flow, so as to lift the water and pour it into a relatively high ditch.

Dumping is also a water lifting tool, but it can also be used for drainage and irrigation.

Zhu Youxiao looked at these big waterwheels and couldn't help but light up. Making this stuff can increase jobs! Obviously a very good construction project.

"Aiqing, in case of flooding, this overturned car is probably not going to be useful!" Zhu Youxiao looked at these big overturns with some doubts and asked.

"Your Majesty, the overturned car is mainly used for drainage and irrigation, and the real flood control has to rely on the embankment. If it rains heavily, the first thing to do is to drain the water into the river, and that's when the rollover comes in handy. Then, it depends on whether the river dam is strong, and if the dam falls into disrepair, flooding will occur. Xu Guangqi is obviously an expert in this area, and Zhu Youxiao seems to be a little inexperienced in this area.

"That's it!" Zhu Youxiao nodded.

"At present, the embankment is mainly built by the Royal Agricultural Company while it is being reclaimed, and then under the Cabinet of Ministers, the Forced Labor Act is required for 20 days per household. The embankment can be well maintained. If it is a year of great drought. There is a problem with the water intake from the river. We can also take the method of well irrigation. Xu Guangqi said, and took Zhu Youxiao to visit the irrigation well.

I saw that this was a well with a very small caliber, with a diameter of only a dozen centimeters. Zhu Youxiao asked in surprise, "What kind of well is this?" ”

"Qi Yu Xià, this is Zhuo Tube Well, Sichuan Salt Well is mostly like this." Xu Guangqi introduced, Zhu Youxiao asked strangely: "How much water can be produced from such a small well?" ”

"Although this well is small, it can penetrate more than 100 zhang underground. It is not slow to take water, just insert a small tube into it, and then pull the blast with animal force to pull it out. Just one well is enough for a farmer to irrigate. In addition, in the area east of Langfang, the upper groundwater is salt water, and it must be drilled deep enough to obtain fresh water. Moreover, digging a well in this way does not require much to choose the location, as long as it is drilled, there will definitely be water. Xu Guangqi's words shocked Zhu Youxiao.

Hundreds of zhang?

That's a few hundred meters deep!

How could there be such a technique in ancient times?

It is normal for Zhu Youxiao not to understand ancient drilling techniques. I've never been exposed to anything about it myself. In fact, the drilling technology in ancient China was very advanced.

This kind of salt well, which reaches a depth of several hundred meters, is a salt well mining technology developed in Sichuan during the Song Dynasty. That is, the tonning drilling technique. The so-called dun drilling, that is, the use of non-rotating drill bit to drill down, although there is no motor to drive the drill bit in ancient times, but to let the drill bit drill down is still very simple, manpower, animal power can be.

In the Qing Dynasty, this kind of drilling technology set a drilling record of 1,200 meters deep. After 1850, Westerners drilled to a depth of only a few hundred meters, 700 years later than China.

The world's first oil well, which was actually drilled in Shaanxi, can still produce 200 kilograms of oil per day in the 21st century.

The so-called first oil well in the West was more than 20 years later than China. Westerners have always talked about so-called inventions, and if there were something in ancient China, they would turn a blind eye to and exclude China.

Su Shi, a poet of the Song Dynasty, wrote in "Shu Salt Said": "All tube wells use machinery, and everyone knows where the benefits are." ”

Originally, this kind of drilling activity was very tiring, and the government usually sent prisoners to drill wells. By 1253, the Sichuan region first used oxen as the driving force for the wheel. The use of animal power instead of manpower is undoubtedly a driving force for drilling and drilling, removing cuttings and mining brine.

This kind of drilling technology, known as 'China's fifth great invention', but naturally there are shortcomings, that is, it is difficult to drill down when it encounters rock formations, after all, it is not a rotating drill bit, but a ton drill, in ancient times when there was no power machinery, rotary drilling is obviously a fool's dream. However, the rock formations in the North China Plain are relatively small. The geological structure is mainly sand and clay, and it is very easy to drill. Even if you hit a rock formation, you can continue to drill down with a special drill bit, but it is relatively slow.

Under Xu Guangqi's introduction, Zhu Youxiao quickly learned about this technology.

Sichuan people dig Zhuo tube wells, mainly using Sichuan bamboo, hollowing out the bamboo joints, and then connecting them into the ground. First open a large mouth, Nanzhu into the ground about 50 meters, so as to isolate the underground fresh water, and then use a drill bit to open a small mouth, and then hit down dozens of meters, so as to contact the brine.

If there is a problem with the sealing of the place where the bamboo is connected, and there is a leak, it is called a 'leaky well', and the well will be invalidated.

"To the east of Langfang, the Zhuo Tube Well we drilled is the opposite of mining brine, mainly to isolate the upper layer of salt water and draw fresh water from the lower layer. In other areas of the saltwater area, it doesn't matter whether this kind of Zhuo tube well leaks or not, as long as it is drilled deep enough, even if it is a drought for ten years, there is no fear of no water. Xu Guangqi continued to explain, "Under normal circumstances, as long as there is no saline aquifer, in the Beizhili area, there is groundwater in some places where one zhang (about 3 meters) is hit, even if the groundwater is deeper in some places, we can use it at most seven zhang, even if it is a major drought, we can generally survive it." ”

The upper groundwater is open and can be replenished by rainwater, and in the coastal area of the Bohai Bay east of Langfang, seawater seeps into the upper groundwater, so it becomes saltwater. At the same time, the upper groundwater will also produce a certain amount of evaporation, but the evaporation efficiency is relatively low.

At this time, the shallow groundwater of the North China Plain in the Ming Dynasty was buried at a very shallow depth, which was not much different from the liberation period in later generations. The water level is generally 2~3m below the surface, and some areas are like the front edge of the alluvial fan in front of the mountain, and the depression between the fans, and there are many springs distributed. This is where groundwater is exposed to the surface. This situation shows that the groundwater is widely distributed, shallow and abundant.

Because there is no large amount of industrial and urban water, and the water used for agriculture is mainly some earth wells, which are not dug deeply. Because there is no way to dig deep, as soon as the groundwater is dug deeply, it comes out, and people cannot continue to dig the operation. Therefore, the groundwater resources of the North China Plain are simply an underexplored treasure!

As long as the groundwater can be extracted, I am still afraid of a drought at the end of the Ming Dynasty! If the river is managed clearly and the flood does not occur, then it is proper to ensure the harvest from drought and flood!

Drilling techniques are different from earth wells, people do not need to dig into the well, they can dig very deep. It is possible to dig all the way to the lower groundwater, which is an area that replenishes more slowly, but also has a large amount of water, and is generally buried at a depth of less than seventy or eighty meters.

Zhu Youxiao immediately realized that the technology was very good, and that later China also used drilling to extract groundwater, and it could also reach the level of overexploitation.

"If Zhuo Tsutsu Jing can be popularized, it can indeed solve the problem of drought. But is it high in terms of cost? Zhu Youxiao hurriedly consulted, if the cost is too high, it will be in vain!

"If the Zhuo tube well is not dug deeply, the construction amount is very small, mainly because of the material cost. In Sichuan, the bamboo is driven into the ground, and we use iron pipes. At present, the cost of steel is also very low, and the quality of iron pipes is not as high as that required for musket artillery, and it is easy to build. As long as it is not a saltwater area, the depth of the well is up to ten zhang, and the iron pipe that is driven into it is okay even if it leaks, and the main role is to ensure that the wellhead is not blocked by the soil, and two craftsmen can make a good hole in three days. If it is in a saltwater area, it is necessary to drill down about 30 zhang to draw deep groundwater. The iron pipe should be sealed, and even if it leaks, we can pull the iron pipe out again and replace it, and there is no need to abolish it. The labor required is still not much, mainly animal power, and the cost of materials. ”

When Zhu Youxiao heard this, he was immediately overjoyed, the cost is so low, it is simply an artifact, an absolute drought-resistant artifact.

The brackish waters in North China are mainly on the eastern coast, and most of the groundwater in the region is freshwater. Even in the saltwater area, the cost of hundreds of meters of iron pipes is still affordable with the support of the state.

"What about pumping?" Zhu Youxiao continued to ask Xu Guangqi.

"Pump the water to the water." Xu Guangqi replied.

"Okay." Zhu Youxiao nodded happily.

Then I saw a group of villagers, digging an iron pipe into a well with a large bowl mouth, and then connecting it to a water pump. Then a wooden bucket was placed underneath, and as the villagers pressed back and forth, the water was pumped out through the iron pipe and flowed into the barrel.

"If you pump water like this, it will be enough to water your crops in a drought year, as long as you are diligent. But it's not very efficient! Isn't it okay to use animal power? Zhu Youxiao asked, the water pump in the mine is pumped with animal power, and this pumping technology is relatively perfect.

"Your Majesty, because the wellhead is small, it takes a certain amount of time for water to seep. Unless it is directly hit into the water layer, it can be continuously pumped with animal power. Xu Guangqi replied.

"How deep do you have to hit the water layer?" Zhu Youxiao asked, after all, groundwater leakage and water layer are different concepts.

"Some hit to a depth of seven or eight zhang, and some to hit about twenty zhang." Xu Guangqi had already taken the Royal Institute of Science and Technology to do relevant research on drilling, and had a rough idea of the geology in North China. At this time, the emperor asked, but he could answer.

"Since the cost is not high, then directly hit the water layer and then use animal power to run the water pump." Zhu Youxiao happily decided, I didn't expect the Ming Dynasty to be so high-end! It can be used to exploit the groundwater in North China just like later generations. Although there are no such things as internal combustion pumps and electric pumps, if it is to ensure agricultural production, the efficiency of animal power is definitely enough.

Zhu Youxiao, who discovered this sharp weapon, immediately decided to set up a royal drilling team. (To be continued......)