Have you ever seen rivers with a higher river bed than land? Our mother river Yellow river is such a magical river.
In some sections of the Yellow River, the water surface of is 7 or 8 meters higher than the ground, and this height is still increasing, and it will soon reach 10 meters.
The water of the Yellow River comes from the sky
In our country Kaifeng , the river surface is almost as high as the Kaifeng Tower.
This is quite dangerous for people by the river. It is like the Yellow River hanging above people, and it is not ruled out that the dam breaks.
So, why can't we artificially clean up the mud and lower the height of the river surface?
If you want to figure out this problem, we have to first take a look at where these mud and sand come from, and why are there more and more piles?
The Yellow River water is really yellow
The sand of the Yellow River
The source of the Yellow River is very close to The Yangtze River , both in the Tanggula Mountains, and The distance between the two is only more than 1300 kilometers .
In the upper reaches of the Yellow River, the color of the water of the Yellow River is not yellow, but very clear. If not specifically marked, it will be difficult for people to distinguish the upper reaches of the Yellow River from the Yangtze River .
But in the middle reaches, everything changed. The Yellow River flowed through a place called Loess Plateau . This is endless yellow land, with drought, rain, and lack of vegetation.
Loess Plateau
But once it rains, these yellow mud and sand will enter the Yellow River along the river water, and several tributaries in the middle reaches of the Yellow River are also mixed with the mud and sand of the Loess Plateau, and they are all injected into the Yellow River.
The average altitude of on the Loess Plateau is about 2,000 meters. The terrain difference is large, so the flow rate of Yellow River water in this area is very fast, and Hukou Waterfall also appears.
When the Yellow River enters the lower reaches, the flow rate of slows down, and the sediment appears in sediment and sand, forming an endless alluvial plain . This is also one of the birthplaces of Chinese civilization, , which is depicted in the Central Plains in history books.
Central Plains
Silt is rich in nitrogen, phosphorus, potassium and other elements, which is very conducive to the growth of crops. Therefore, the lower reaches of the Yellow River are also the main grain production area of my country . Henan and Shandong are both major grain provinces.
So in the history of our country, The flooding of the Yellow River is half good and half bad . The bad thing is because it destroys houses, causes floods, and floods the fields; the good thing is that the land flooded by the Yellow River will have better harvests in the next year.
The famous Dayu controls the flood . The river it controls is the Yellow River. Dayu also obtained the throne of Shun's abdication because of its contribution to water control. It can be seen how important the Yellow River is in history.
Dayu controls water
However, there are advantages and disadvantages. The Yellow River has too much silt and sand, and has caused the sedimentation in Henan to become thicker and thicker. After thousands of years of precipitation, the riverbed of was continuously raised by , so hanging rivers on the ground appeared.
The Yellow River has 1.6 billion tons of silt every year, Three-quarters of the silt are injected into Bohai , and the remaining quarter is distributed in the lower reaches of the Yellow River to form a plain. The riverbed in the lower reaches of the Yellow River will rise by 8 to 10 cm per year.
Schematic diagram of the hanging river on the ground
The Yellow River has been diverted many times in history, and most of the are natural causes . In more than 2,000 years, the area impacted by Shandong and Jiangsu by the Yellow River is equivalent to a province.
However, the river hanging on the ground is like the Damo Sword of Chris hanging on our heads, It is always a hidden danger .
So why not dig out the excess mud and sand in the river to lower the water surface of hanging river ?
Yellow River water
Manual sand digging
Why can't the above-ground hanging rivers in the Yellow River section be digging out manually? There are three main reasons.
The first reason is that has too much silt and sand , which is a huge project. There are more than 400 million tons of silt and sand scattered in the lower reaches of the Yellow River, and silt and sand are replenishing almost every day.
In other words, when people dig out the mud and sand at the bottom of the river, , the mud and sand at the back of are filled. After all, has half a bowl of sand in for a bowl of Yellow River water, and the filling speed is still very fast.
Silt and sediment deposits of the Yellow River
If you need to dig sand manually, then the excavator cannot leave the riverside and has to dig every day to ensure the cleanliness of the Yellow River riverbed. Obviously, this is too difficult.
The length of the lower reaches of the Yellow River is 786 kilometers , which requires the excavators from all over the country to use. Lanxiang’s excavator masters are not enough.
This plan is basically impossible to achieve in terms of manpower and financial resources.
The second reason is that digging the silt at the bottom of the river will cause great ecological damage . In the past, due to lack of strict supervision in my country, rivers in many areas were illegally mined by people.
working sand mining ship
After the silt in the riverbed is dug up, will change the flow rate of the river and affect the normal navigation of the ship .
Silt and sand have an hindering effect on river water . After the silt and sand is dug, the river water flow speed will accelerate. If a flood occurs at this time, it will cause serious damage to the downstream areas.
After digging away the silt and sand in the lower reaches of the Yellow River, the river surface will indeed drop, but at the same time, the water in lakes and reservoirs will flow backwards .
Therefore, normal rivers cannot dig out river sand on a large scale, let alone special rivers hanging on the ground.
Yellow River Basin
The third reason is, where is the dug out of the mud and sand? silt cannot accumulate at will, otherwise it will easily lead to disease transmission.
can be found by putting it under a microscope. There are bacteria, viruses, fungi, actinomycetes, rickettsia, Mycoplasma , Chlamydia , spirochete , and spirochete and other microorganisms.
We often smell the silt odor, which is emitted by the above creatures.
smite in the Yellow River Bed
smite in the ancients often said that plague will occur after the flood . In fact, it is the flood that silt and sand that swells. After people come into contact with the flood, they are infected by various bacteria and then spread to each other.
Rustly digging the mud and sand at the bottom of the Yellow River is a very dangerous thing, and it may cause infectious diseases.
Therefore, the silt and sand of the Yellow River cannot be dug out.
Yellow River flood
Control silt
Instead of spending a lot of effort to dig silt, it is better to solve the problem from the source of silt . Where does the silt in the Yellow River come from? Most of them are from the Loess Plateau.
Loess Plateau is blocked by Qinling . Siberian The sand blown by the cold wind cannot pass through it and accumulate here to form , which was formed about 8 million years ago .
The area of the Loess Plateau was not as large as it is today, reaching its current area. Among them, there are The reasons for overgrazing and reclamation of humans .
For the Loess Plateau, we cannot let the loess disappear in a short period of time, and we can only manage it in a gradual manner.
Loess Plateau turns green
Fortunately, the Loess Plateau is not a desert, plants can be planted on it. You can plant drought-resistant plants such as sea buckthorn, splendens according to local conditions to stabilize the soil and soil.
In this way, the silt and sand of the Yellow River enters every year due to rainwater will gradually decrease . In the long run, the water of the Yellow River will be clear for a day.
However, some people raised concerns. The lower reaches of the Yellow River rely on the silt and sand of the Yellow River to maintain fertile soil. Will the reduction in silt and sand affect the grain output downstream?
The lower reaches of the Yellow River
The Loess Plateau is not to control it without any grain of sand, and The normal silt and sand supply will not change due to greening . For example, there are so many trees in the Amazon rainforest, it will not affect its normal rivers.
The main problem in the lower reaches of the Yellow River is that there is too much silt and sand, and has exceeded the amount of silt that can be accommodated .
There is in it. Many silts are accumulated in the riverbed by , which cannot be accumulated on the plain. The control of the Loess Plateau is to prevent these excess silts from entering the Yellow River.
The Yellow River carries a large amount of silt
The Yellow River and the Bohai Sea
The Yellow River brings so much silt every year, why haven’t I filled the Bohai Sea in so many years?
In fact, the Bohai Sea we see now is what the Yellow River looks like after the reclaimed sea , and the Bohai Sea has disappeared nearly one-third of its area.
However, this is The Bohai Sea has shrunk in millions of years. It is impossible to see the obvious shrinkage in thousands of years.
Also, The amount of silt in the Yellow River is , where a large number of people living in Guanzhong area began to soar. According to historical records, it was called "river" during the Spring and Autumn Period and the Warring States Period, and did not add the attribution of yellow .
Bohai Sea terrain
The title of Yellow River begins to appear in history books, which can be traced back to Han Dynasty . It just so happened that the Han Dynasty began to live in Guanzhong area with a large population, which shows that it should have turned completely yellow at that time.
Many dynasties after the Han Dynasty used Chang'an as the capital, which also made the population of Guanzhong area large, and human activities further expanded the area of the Loess Plateau .
It seems that the time when the Yellow River injects a lot of silt into the Bohai Sea is only 000 , which is too short for changing the landform.
The mouth of the Yellow River
Therefore, The Yellow River cannot fill the Bohai Sea in a short time , but it may be possible for a long time. In theory, it can fill the Bohai Sea.
Of course, this assumption may never be realized, because my country has achieved results in the governance of the Loess Plateau, and the amount of sediment in the lower reaches of the Yellow River has dropped to .064 billion tons of , which is similar to the Spring and Autumn Period and Warring States Period.
The Yellow River enters the sea in Shandong, and the water quality is no longer turbid, The Yellow River will one day not be yellow again .
The long river sets in the sun circling
However, as a cultural imprint, it has been deeply engraved in the hearts of the Chinese people. Even if it becomes clearer, it is still the Yellow River in our hearts.
