The Ming Dynasty did not revolutionize

Chapter 220 Can the Great Lakes Have Other Important Functions?
Zhu Jianxuan asked Wang Lai with a very serious expression:
"Have you ever considered whether so much water piling up in the valley would have any impact on the ground?
“Will it collapse the geological structure or mountains, triggering natural disasters such as earthquakes and volcanic eruptions?

“What impact will that have on winter and summer temperatures and rain and snow in surrounding areas?”

Wang Lai said very frankly:

"Teacher, the Academy of Sciences currently has no such experience.

“However, we can use the Sanjiangze Reservoir for experiments and collect data in this regard.

“The Sanjiangze Reservoir is sparsely populated and surrounded by tall mountains and primeval forests, and is also very close to the sea.

“If a very obvious geological disaster is discovered during the construction of the dam and the water storage process, the water can be quickly discharged into the sea and the water storage process can be quickly stopped.

"The data collected in this process can be used as a reference for building reservoirs in densely populated inland areas.

Zhu Jianxuan felt that what Wang Lai said made sense...

In places like the Three Gorges Dam, there are large populations both upstream and downstream, and a large number of residents have to be relocated during the construction process, so there is no way to release the water storage.

Unless the entire Chongqing area turns into a lake, it will be possible to store trillions of cubic meters of water.

Zhu Jianxuan was slightly moved.

But... no matter what, the flooded area is still too large, at least a plain of 100,000 square kilometers.

The point is that there is no point in drowning.

The amount of water in Heilongjiang River in a year can only raise the water level by three to five meters, and the amount of water consumed each year is also limited to this number.

The remaining dozens of meters of water, which is the water volume of Heilongjiang River for decades, will be sealed deep in the lake forever.

Even for shipping, to block the Sanjiangze River Valley, the water depth does not need to be several dozen meters.

Moreover, blocking the Sanjiangze River Valley is not a permanent task. It will not be necessary in forty or fifty years at most.

What Wang Lai said sounds good. The reservoir can be used to silt up farmland and drain water in the future.

However, according to later experience, once this reservoir is successfully built, hydropower will be supplied to the surrounding cities.

Unless there is a comprehensive decline in industrial capacity and the country's electricity consumption begins to decrease on a large scale, it is impossible to demolish such a hydropower station.

Like Hongze Lake and Gaoyou Lake, they were formed by storing water on the plains, flooding more than 2,000 square kilometers of plains.

On a large plain that slopes slowly from west to east, large embankments running from southeast to northwest were built in the lower eastern part of the area, forcing the water flow to be blocked in the upper reaches, forming a lake.

They are all "hanging lakes on the ground".

If it rains in the Huaihe River Basin, the area of ​​Hongze Lake will expand rapidly.

Because the water in Hongze Lake is very shallow and the bottom of the lake is a gentle slope, the water becomes shallower as you get closer to the northwest edge of the water area.

It is such a hanging lake on the plain. In ancient times, it was used to supply water for canal transportation. In modern times, it is used to ensure irrigation of farmland in the lower reaches of the Huaihe River. There has never been a possibility of demolishing it.

Before Xuyi and Sihong counties were transferred to Jiangsu, Anhui and Jiangsu would clash whenever there was heavy rainfall in the Huaihe River basin.

Anhui certainly wants to break the dike to drain the water, but Jiangsu will not allow its land to be flooded.

The two sides even went to war.

The direct reason for assigning Xuyi and Sihong to Jiangsu is not just to manage Hongze Lake.

More importantly, Anhui should not be adjacent to the Hongze Lake dike, so that Anhui cannot blow up the Hongze Lake dike without any consequences.

Avoid direct conflict between the two neighboring provinces over whether to release floodwaters.

But even so, when Anhui encountered flooding, the two sides would still engage in a war of words.

Even so, Hongze Lake cannot be moved.

Therefore, when Zhu Jianxuan established the Huaihai Provincial Administration, he put the main stream of the Huaihe River, Hongze Lake, and Gaoyou Lake together.

It is now easier to manage and avoid direct conflicts, and it also prepares for the comprehensive management of the Huaihe River Basin in the future.

After all sorts of thoughts flashed through Zhu Jianxuan's mind, he asked another question:
“Is there any way to separate the water storage area of ​​the silted fields from the water storage area of ​​the future hydropower station?

"For example, if the silted fields within the Sanjiang Lake are navigable, the water storage depth can be as deep as 10 to 20 meters.

"The Xingkai Lake Plain is used to store water for power generation and can be raised to more than 100 meters...

"In the future, when the time is right, the water in Sanjiang Lake can be drained, but Xingkai Lake can continue to generate electricity."

Wang Lai answered subconsciously:

"Teacher, the main stream of the Heilongjiang River and the Songhua River are in the Sanjiang Lake, and the terrain of the Sanjiang Lake is lower than that of the Xingkai Lake Plain.

"Before the Sanjiang Lake is full, the water from the Heilongjiang mainstream and the Songhua River cannot enter the Xingkai Lake Plain.

“Unless we spare no expense, we can build a dam 70 to 80 meters high and hundreds of kilometers long on the river valley plain under the hillside to divert the water flow into the Khanka Lake Plain in advance.

“Otherwise, the Xingkai Lake Plain can only rely on the upper main stream of the Ussuri River for water storage.

"The runoff of this part of the Wusuli River is definitely much lower than that of the Heilongjiang River and other major tributaries, and the difference may be an order of magnitude.

"The area of ​​the Xingkai Lake Plain is about one-third of the Sanjiangze.

"Therefore, using the entire Heilongjiang River to store water for the entire Sanjiangze and Xingkai Lake Plain at the same time will be much faster than using the upper reaches of the Ussuri River to store water for Xingkai Lake alone.

"Based on the ratio of the amount of water injected to the flooded area, flooding only the Khanka Lake Plain would definitely be more wasteful than flooding both the Khanka Lake Plain and the Sanjiang Lake.

“The Khanka Lake Plain will also certainly be flooded because the northern outlet of this plain is lower than the southern outlet.

"After closing the northern outlet into Sanjiangze, the water from the Wusuli River will have to fill up the entire plain before it can be discharged from the southern outlet.

"Unless we build a canal with a maximum depth of more than 40 meters and a length of several hundred kilometers..."

Zhu Jianxuan confirmed that there was no way to compromise on this project.

If we are to flood, we must flood everything. Flooding everything is the most efficient, has the least engineering difficulty and the lowest cost.

Even the only feasible option is total flooding.

Blow up the rocks to block the exit of the valley, and wait for the water to accumulate on its own.

As for other compromise ideas, a little calculation will reveal that they are completely uneconomical in terms of cost.

Whether it is a dam that is hundreds of meters long and dozens of meters high, or a canal of the same size, the cost will be a terrifying astronomical figure.

We can only consider whether this super large reservoir will have other great uses.

Otherwise, if it is just for generating electricity, there is no need to do this.

If the sole purpose is to blockade and control the inland, one can simply and crudely blow up the mountains and block the rivers, forming a lake with a maximum depth of ten to twenty meters, without having to pile it up to a depth of several dozen meters.

The actual engineering cost of this type of project is the lowest. At the same time, if there is no constraint from the power station's profits and electricity users, the dam can be opened at any time.

So what great role can a huge reservoir that can release water steadily throughout the year play?
“Water transfer from north to south?”

So Zhu Jianxuan asked Wang Lai again:
"You also said before that if the dam on the Heilongjiang River is too high, it may cause the Songhua River to flow backwards, and the river water will flow from the Liaohe River into the Bohai Sea?"

Wang Lai immediately said:
"Yes, teacher. If the water level of the dam exceeds the altitude of the upper reaches of the Songhua River, the river water will flow back to the heart of the Northeast Plain.

“The Northeastern Plain is also high on all sides and low in the middle, and can be considered an even larger valley in the mountains.

"There are only two exits from this huge valley. One is to enter Sanjiangze through the Songhua River, and the other is to go south to the Liaohe River.

"We blocked the downstream outlet of Sanjiang Lake. When the water in Sanjiang Lake is full, it will naturally flow toward the Liaohe River.

"As long as we dredge a water diversion channel at the lowest point of the plain valley, the water can flow through the natural incision and slowly form a natural river channel that is wide enough."

Zhu Jianxuan immediately asked:
“Then is there a relatively simple way to deliver as much of the river water flowing southward to the capital and North China at a relatively controllable cost?

"The key is to keep the cost under control and to ensure that the water volume is large enough. For example, is it logically possible to send all the water from Heilongjiang?"

Wang Lai and the ministers around him were all shocked:
"Teacher, what you mean is... all the water from the Heilongjiang River? Bring it to the capital? Why should we do this?"

Zhu Jianxuan couldn't explain it now:

"Why don't you just ignore it and analyze this matter first to see if it's logically possible."

The craftsmen and officials of the Ming Dynasty had no idea about it, but Zhu Jianxuan was deeply impressed by the water shortage problem in North China and Beijing.

Zhu Jianxuan's early decentralization of the capital's functions was actually just to avoid concentrating water use in one place, but it could not reduce the overall water consumption.

The water pressure in the entire North China region will not decrease, but the harm will not be immediately apparent because the water supply will be more evenly distributed.

If we want to fundamentally solve the water shortage problem, we still need to have sufficient supply of fresh water resources.

At the starting point of the South-to-North Water Diversion Project in the past, the inflow into the Danjiangkou Reservoir was only 388 billion cubic meters, which was not enough to meet the industrial and agricultural consumption in North China.

At that time, "Southern Water" was actually mainly used as a source of drinking water for the city.

The runoff of Heilongjiang River is as high as 3500 billion cubic meters, which is basically equivalent to the entire Pearl River Basin.

If all of it can be introduced into North China, it can fundamentally solve the water shortage problem in North China.

If North China were not short of water, agricultural conditions would definitely be better than those in Northeast China, especially better than Sanjiangze.

Wang Lai began to think and said:

"Teacher, the students have roughly...assessed it.

“From the upper reaches of the Songhua River to the capital, we should be able to find a relatively flat route, bypassing all the mountains.

“The total distance should be around one thousand kilometers.

"If we want to transport all the water from the Heilongjiang River, the key is to use the plain river channel. It is estimated that a canal with a width of at least 500 meters and a depth of at least 20 meters will be needed to be safe.

"The amount of earth that needs to be excavated for the river alone is 10 billion cubic meters, which is completely beyond the current engineering capabilities of the Ming Dynasty.

“It’s impossible to dig a canal straight down from the ground.

"If we build a dam in the Bohai Sea a few dozen meters away from the shore as a channel into the sea, we can use the river water entering the sea to wash away the seawater in the dam.

“This would allow fresh water to be delivered directly to the coastal areas of Tianjin, but it would not be able to be delivered to the capital or the inland areas of North China.

“If we want to send it inland, we can only consider building river embankments on the ground.

“We can try to build two 10-meter-high riverbanks in parallel on two lines one kilometer apart.

“It’s like the Yellow River embankment.

“In fact, if you don’t care about the flooding range, let alone a river width of one kilometer, even ten kilometers will not be a problem.

"The wider the river, the lower the required embankment height and the smaller the engineering workload." If there are mountains along the way, you can start from where the river leaves the valley and build a large embankment along the foot of the mountain on one side.

“Let the river flow southward along the foot of the mountain through the gap between the hillside and the riverbank.

“This will allow the two levees to become one.

"It just so happens that more than half of the canal's range from its starting point to the vicinity of the capital is at the foot of the Yanshan Mountains, and the Taihang Mountains are to the west of the North China Plain...

“The interior of the Northeast region is also high around and low in the middle, and can be considered to be at the foot of a mountain range with a particularly gentle slope.

"In theory, most routes can be built with just one riverbank..."

Wang Lai was thinking as he spoke, and when he got to this point, he seemed to become entangled:
“Teacher, if the canal is really built in this way, the power generation efficiency will definitely be limited.

“In order for a river to flow naturally over a distance of a thousand kilometers, the river channel must be naturally and evenly lowered.

"From the source to the capital, the altitude gradually decreases from more than 100 meters to 50 or 60 meters.

“At most, we will build a power station near Jinzhou, between the mountains and the sea. It is estimated that the height difference of about 80 meters can be maintained, and the final installed capacity will definitely be much smaller than the Jinghaifu plan.

“But we can gather all the rivers on the hillsides along the way into this canal, so we can increase the amount of water.

“As long as the riverbank is built to 15 meters high, the canal can be more than 10 meters deep.

"Then the largest ship in the world could sail from the capital to the northeast, to Sanjiang Lake, and then sail to the sea from Nurgandusi...

"If necessary, we can even build levees along the Yanshan and Taihang Mountains all the way to Henan and even Shandong, and inject water into the Yellow River, Huai River and even the Yangtze River.

"The key is to be able to inject water into the highest point of the Grand Canal! That way the Grand Canal will have a nearly unlimited and controllable water supply.

"We no longer need Hongze Lake and Gaoyou Lake in the south to supply water to the canal!

"Even the Grand Canal can achieve full gravity flow, and all the previous locks can be directly abandoned!"

Ordinary people of that era were not very interested in simply bringing water to North China.

But if we could bring the water into the Grand Canal, that would be a big deal.

So when Wang Lai finished speaking, his emotions became obviously excited again.

Zhu Jianxuan listened to Wang Lai's enthusiastic ideas and fell into a brief moment of recollection and thinking.

The South-to-North Water Diversion Project's middle route in the past was also gravity-flowing.

A long section of the canal runs along the foot of the Taihang Mountains, with a slowly decreasing altitude built according to the contour lines. The entire route is about 1,500 kilometers.

However, this canal was dug downwards, and its width is only fifty meters.

The Red Flag Canal in the revolutionary era was also a gravity-flowing canal built along the contour lines along the foot of the mountain or even on the hillside.

The scale of both is far smaller than what Wang Lai had imagined.

Wang Lai’s plan is to build a super canal with a width of kilometers, which can even be considered a long and narrow reservoir.

Can this thing really be built? Is it really feasible?

Zhu Jianxuan asked a few questions subconsciously:

“Is it feasible in terms of engineering? Is the cost controllable?

"Building a canal along the foot of the mountain will create a completely suspended river in the sky for the area at the foot of the mountain?

“The key is, what if a landslide occurs? Will it directly block the entire canal and cause major flooding in the area where the canal flows?

"Also, how can the river flow through the Liaoxi Corridor? The terrain here is narrow and there are many mountains."

Wang Lai once again carefully considered the details of this plan:

“Students believe that engineering and cost issues can be roughly divided into three situations, depending on whether the altitude and slope along the route are suitable.

“If the height and slope are appropriate, for example, for every kilometer away from the foot of the mountain, the altitude will drop by ten meters.

“Then we only need to build a 15-meter-high embankment to form a super canal at the foot of the mountain with a width of one kilometer and a maximum water depth of twelve or thirteen meters.

“The actual engineering workload and cost in this case will be less than that of the Yellow River embankment.

“Because the canal embankment can take soil from the high hillside, or even directly blast the hillside, and pile the soil and rocks in the lower part of the land to form a simple embankment.

"The Yellow River embankment was built by taking soil from the flat land far outside and piling it on top of the embankment on higher ground.

"If the slope is too small, for example, there is only a ten-meter altitude difference within a dozen kilometers, and the river water has to reach the predetermined depth, if only a single-line river embankment is built, the flooded area will be very large.

“In this case, it is necessary to build a double-line river embankment to allow the river water to flow between the two embankments.

“The costs will certainly increase at this time, but they are still manageable.

"If the slope is too steep, it would be like digging a canal on the mountainside, and the engineering difficulty would be the greatest at this time.

“If the standards cannot be met, large-scale detours will be needed.

“Farther away and lower, look for a flatter place and build a high enough levee.

“The canal would then flood the area between the actual route and the theoretical optimum, creating an additional small reservoir.

“The specific engineering difficulty and cost will be estimated based on the actual flooding range and depth.

“At this point, the cost and workload may get out of control.

“For example, if we need to build a dam that is dozens of meters high and hundreds of kilometers long, the engineering will be uncontrollable.

“Whether there are similar areas along the route that cannot be avoided determines whether the project is feasible.

“The direction of engineering planning is to make the canal route as gentle as possible and avoid any excessively steep slopes as much as possible.

“If the plan is confirmed to be feasible, the remaining issue will be the migration of people along the flooded areas.

"It shouldn't be a big problem for the canal to cross the Liaoxi Corridor, as there are several kilometers wide coastal plains and gentle slopes along the way.

“If you need a high altitude, go closer to the mountains; if you need a low altitude, go closer to the coastline.

"In order to prevent landslides and mud-rock flows, double-line embankments can be built wherever the embankment passes through the river valleys in the mountains, forming small flood discharge reservoirs in the valleys inside the river channels.

“At the same time, we utilized the existing rivers on the plains to build a large number of canals for irrigation and drainage.

"Especially in the Liaoxi Corridor area, where rivers and canals are closest to the sea, large-scale sea access channels can be built to directly drain the main river channel from upstream.

"At the outlet of the Sanjiangze reservoir, we will also build levees and sluice gates. If a landslide occurs below and blocks the river, we will immediately close the upstream sluice gates.

"Since the reservoir itself is huge, as long as a few meters of storage capacity is left, it can accommodate a whole year's water volume, and there is no need to worry about not being able to control the water flow upstream.

"This type of canal is indeed a suspended river above ground, essentially a huge elevated aqueduct above ground, which of course carries the risk of breaching its banks.

“But above-ground aqueducts are not without their benefits, because water will naturally flow to lower places.

“As long as we reserve a water outlet pipe in the river bank and set up reasonable sluices and valves, the river water will flow naturally when the valves are opened, directly irrigating the farmland below.

"The excess river water after irrigation will converge into a large number of east-west rivers in North China and eventually flow into the Bohai Sea.

“If all the water from Heilongjiang is diverted to North China, most of the farmland in North China can be converted into paddy fields.

“Finally, both the Liaoxi Corridor itself and the route from the Liaoxi Corridor to the mainstream of the Songhua River.

“Or maybe the route from the capital to the Liaoxi Corridor, or the route from the capital along the Taihang Mountains to western North China and Henan.

“They are all routes that are very suitable and necessary for the construction of trunk railways and roads.

“The canal embankment is built according to the contour lines, and the overall slope will be very uniform, which is very suitable as the roadbed for railways and highways.

"In this way, the cost of the levee can be partially offset by the railway and road construction budget.

"The sand content of the Heilongjiang River is much lower than that of the Yellow River. Its normal flow will not leave too much sediment and will not continuously raise the riverbed like the Yellow River.

“It only requires regular repair of the embankments that have been eroded by side cutting. The canal will even continue to deepen due to the natural downcutting of the river, and the embankments may eventually become dispensable.

"Overall, it can take into account water diversion, navigation, irrigation and power generation. Students think it is a great project that will benefit the present and future generations."

After listening to this, Zhu Jianxuan fell silent again.

The biggest cost of this super canal is the resettlement of flooded land…

Now the Ming Dynasty has a large amount of land overseas and can settle immigrants to the new overseas lands on a large scale.

The imperial court also had a large amount of local land in its hands, which could be used to accommodate immigrants who were really unwilling to go to sea.

At that time, the population in Northeast China was small, and the canal was located on the westernmost side of the Northeast Plain. Those places were actually nomadic areas and there were basically no fixed settlements.

Therefore, the immigration cost of this project that submerged the land is nothing to the current Ming Dynasty.

After deducting the cost of immigration, the length of the embankment from Liaodong to the capital is about 1,000 kilometers, and the final cost may be similar to that of building the Yellow River embankment.

The total length of the Yellow River embankment should be 1,500 kilometers.

So it is equivalent to rebuilding the Yellow River embankment, and then the water shortage problem in North China can be completely solved?

Can we also use the construction costs of highways and railway subgrades to share a large part of the engineering infrastructure costs?

Why does this feel so unreal?
Because there were too many constraints in the previous life, there were too many immigrants along the route, and the key was that there was no place for immigrants. Overall, it was still a foreign-related project, so there was no possibility of implementation at all?
Or, even the cost of the Yellow River embankment is actually very high.

The Yellow River must be controlled. If the river embankment is not repaired, it will cause a disaster. It must be repaired no matter how high the cost is. However, the canal itself can be left unrepaired.

At the same time, if this canal is built, it will be even more impossible to demolish the Sanjiangze reservoir.

Even if a natural disaster occurs in the surrounding areas of Northeast China, it cannot be demolished.

Zhu Jianxuan considered it for a long time and did not rashly give any affirmative answer. He simply arranged for the Ministry of Water Resources to complete the formalities and then organized personnel from the Northern Industrial Corporation to conduct on-site exploration.

Find out the specific local conditions and make a detailed feasibility report:
Wang Lai also wanted to directly participate in this exploration, but Zhu Jianxuan directly stopped this child who was obviously a little excited:

"If we let others do this, the data we get in the end will be more objective.

"You should concentrate on studying the problems of the Yellow River and the Huai River.

“It doesn’t matter whether the Sanjiangze Reservoir is repaired or not, but the Yellow River and Huai River must be regulated.

"If you can do it well, your name will go down in history.

"You were the one who proposed the wonder of Sanjiangze. Your name will definitely be left on it. You don't have to worry about it anymore."

(End of this chapter)