100 help plan
Who would dare to believe that the Yellow River can get rid of the mud and sand!
The Yellow River is full of floating sediment particles, so the riverbed is raised, forming an above-ground river downstream.
The generation of above-ground rivers is the result of long-term development, and it is difficult to effectively solve it, and sediment is one of the most difficult passes.
Nowadays, with the development of science and technology and the changes of the times, sand adjustment has been achieved in only 22 years500 million tons, our mother river will finally have a new look.
The feelings of the Chinese people towards the Yellow River are not understood by many Westerners, after all, Chinese culture has a long history, and the trend of the world has always been divided for a long time, and it must be divided for a long time, why is it so close to a river?
In the course of 5,000 years of culture, the Yellow River has always occupied a place, and its gurgling and magnificent nature gave birth to the early Chinese civilization.
Some people say that China is a culture disguised as a country, and the Yellow River is the birthplace of this culture.
Therefore, the Chinese also affectionately call it the "mother river".
The Yellow River is sometimes low and tactful, sometimes irritable and roaring, and it is precisely because the "Mother River" has such a unique character that the people living in this land will unite to appease the "Mother".
Perhaps there is such a reason that China is not as scattered as Western countries, either in internal fighting or on the road of internal fighting.
Take the two parties in the United States as an example, they are harmonious on stage, but they directly tear their faces in private, and you rob me of my interestsOkay, we'll see next time.
The people on both sides of the Yellow River are different, bearing the blessings and rain of the same "mother", even if there is a conflict of interests, they will not forget that they are a family.
The Yellow River is located in the northern part of China.
The "yellow" in the name of the Yellow River, in fact, refers to sediment, and it is recorded in ancient books: "The Yellow River fights water, and the mud occupies its seventh", which means that a bucket is taken out of the water of the Yellow River, and the soil occupies seventy percent of the weight.
Where does so much sediment come from?
This starts from the source of the Yellow River, which originates in the ancient Zonglie Basin at the northern foot of the Bayan Kala Mountains on the Qinghai-Tibet Plateau.
China's topography is divided into the first step, and its tendency is from west to east, from high to low.
Therefore, most of the horizontal rivers in our country flow from west to east, which is why many poems will write: "East flowing water".
The Yellow River is no exception, flowing from west to east, from the majestic Qinghai-Tibet Plateau, flowing through Qinghai, Sichuan, Gansu and other provinces, and finally employs majestically into the Bohai Sea.
When it first came out of the Qinghai-Tibet Plateau, the water of the Yellow River was still clear, and although it encountered steep terrain on the way, it did not impact much sediment.
Until the water of the Yellow River crosses the tense and exciting upper mountain area, it slowly comes to the plains and hills in the middle and lower reaches.
A plateau full of ravines, with a huge amount of loess and sand, greets the arrival of the Yellow River with a smile.
It is the Loess Plateau in China, a place where soil erosion is so serious that it has repeatedly climbed the geography test paper of the third year of high school.
Loess Plateau, as soon as you hear the name, you will know what the "specialty" of this region is, that's right, loess!Loess all over the mountains!
The yellow sand is flying, the land is barren, and the Loess Plateau resembles a middle-aged person with unusually severe hair loss, with intricate ravines on the surface, and occasionally a few scattered vegetation plants taking root on the bare surface.
As soon as the Loess Plateau passes through flowing water or heavy rains, the gravel on the surface will flow into the lower riverbed with the rolling water.
The Yellow River, which was originally crystal clear and beautiful, was dyed with "yellow hair" in this way, greatly changed its green appearance, and became babbling.
Because of the large amount of sediment, the Yellow River is also known as the river with the most sediment content in the world, but in fact, ninety percent of the sediment of the Yellow River comes from the Loess Plateau, which is really "damaged".
However, even as the sediment in the river increases, the Yellow River still tirelessly raises its children born by the river.
The Yellow River Basin has long winters and short summers, the temperature difference between winter and summer is huge, and the seasonal temperature changes are distinct, because the precipitation is small, and the development of dryland agriculture is mainly carried out in all directions.
The total length of the Yellow River is about 5,464 kilometers, and the total area of the basin is 7950,000 square kilometers, since ancient times, has nurtured countless Chinese to settle down.
Despite its size, the Yellow River does not carry much runoff, compared to 17 times as much water that the Yangtze River flows into the sea each year.
However, in the middle and lower reaches of the Yellow River, there is a historical problem – that is, the flooding of the Yellow River.
Every time the precipitation increases and the flow increases, the Yellow River floods, causing huge damage to the surrounding buildings and farmland.
The runoff of the Yellow River is obviously not large, so why does it flood?The main reason is sediment.
Because the middle and lower reaches of the Yellow River are basically plain or hilly terrain, the terrain is more gentle than the jagged mountains in the upper reaches.
This also leads to the slowing down of the flow rate of the Yellow River, and when the water flow slows down, the huge amount of sediment carried by the water body will gradually be deposited.
The gradual siltation of these sediments raised the riverbed of the Yellow River, which caused the shallow riverbed to carry so much water when the water volume of the Yellow River suddenly increased, allowing the river to flood out.
Earlier, in order to stop the sudden flooding of the river, dikes were built on both sides of the downstream channel.
However, this old method only works for ordinary rivers, and the Yellow River does not eat this set at all, and the sediment is still silted when it should be silted.
As a result, the riverbed has been raised, the embankment has been raised, and finally a shocking "above-ground river" has been formed, which has also led to a kind of fantasy, the riverbed is even higher than the ground!
For example, in Kaifeng City, Henan Province, where the Yellow River flows, the riverbed of the Yellow River is about 10 meters higher than the city's ground.
It's just outrageous to knock on the door - outrageous to home!
The Yellow River has become an "above-ground river" as a result of a long period of development, and people initially built dikes to protect against flooding, but they did not think that this was only a palliative solution.
Although the embankment can be saved for a while, it can't be saved for a lifetime, and the riverbed of the Yellow River is getting higher and higher, so should the embankment always be raised?It's just a fantasy!
In order to cleanse our mother river and reduce the height of the riverbed, the relevant departments of our country began to work hard to control the river.
After a long period of exploration and practice, the water conservancy department chose the most reliable method of water and sand diversion to clean up the river.
Some people may wonder what is water and sand transfer, and in principle, these two methods are actually very simple.
Water and sediment diversion is a systematic project, which mainly addresses the fundamental problem of the Yellow River's flooding - sediment accumulation, so that when the river water increases during the flood period, the surrounding water is overcrowded.
In terms of process, water and sand diversion includes the following three aspects:
The first point is to build water conservancy projects, regulate the content of water and sediment, nurture water sources, and improve water quality.
Because the Yellow River mainly floods in the middle and lower reaches, the construction of reservoirs and dams in the upper reaches of the Yellow River can reduce the sediment accumulation of the Yellow River to a certain extent.
For example, in the event of a flood, we can open the floodgates of the reservoir to allow the sediment-carrying flood water to pass through quickly, hitting the riverbed and carrying the sediment with it.
At the same time, when the weather is hot out of season and the Yellow River enters the dry season, we can close the reservoir gates and control the water flow, so that the water level and flow rate of the downstream river can be more even, and the siltation of the river can be reduced.
Then, the so-called physical means, after the development of human science and technology, the corresponding physical methods began to increase. For example, in areas where there is a lot of sediment in downstream rivers, sediment is transported through blasting, mechanical dredging, etc., to lower the riverbed.
When there is less sediment in the river, the river can flow more freely, bringing more sediment to the sea.
In addition, there are also a variety of engineering assistance such as the construction of river bank protection and vegetation slope protection, and the "multi-pronged" approach is taken to prevent sediment erosion of the river.
These methods not only reduce sediment accumulation, but also reduce the probability of flood disasters, which can improve the flood control capacity of the Yellow River.
The last point, and the most practical way, is to wash the sand with water!
Beam water and sand flushing is to concentrate high-speed water flow in the river channel through the impulse and gravitational acceleration of the water flow, and accelerate the flow speed of the river water.
The high-velocity water hits the sediment at the bottom of the riverbed, levitating it to the surface of the water, where it is carried away by the high-velocity water.
There are two secrets to water and sand flushing, one is to increase runoff in a short period of time, and the other is to narrow the course of the Yellow River.
A narrowing of the river course will increase the speed of the water and speed up the flow through the area, and an increase in runoff will also achieve the same purpose by increasing the speed of the water.
This treatment scheme is very useful, it does not pollute the environment, does not damage the riverbed, and the efficiency of sand washing is very high.
However, it should be noted that although there are effective ways to control the sediment of the Yellow River, we have not completely solved the problem of sediment accumulation.
Soil erosion on the Loess Plateau still causes a steady stream of sediment to flow into the Yellow River, causing water quality to deteriorate and sediment to accumulate.
In order to solve the problem of raising the riverbed of the Yellow River, we also need to find a way to solve the problem of low vegetation coverage and sparse soil quality on the Loess Plateau.
For example, CCTV reported that the runoff of a section of the lower reaches of the Yellow River has increased, the riverbed has dropped, and the water transport capacity has also increased as the river has become deeper.
As of today, we have spent 22 years in water and sediment diversion, and we help clean up about 1.1 billion of the Yellow River every year500 million tons of sediment. Although this is indeed a congratulatory achievement, the sediment problem still has an impact and follow-up.
In order to turn the lower reaches of the Yellow River into a clear state, we still have to make a lot of efforts, and we must pay attention to the problem of soil erosion on the Loess Plateau while controlling desertification.
In addition, it is worth mentioning that after the sediment of the Yellow River flows into the sea, it does not immediately sink to the bottom of the sea, and after entering the Bohai Sea, a lot of sediment is gradually deposited in the Bohai Sea and becomes land.
This has also led to the fact that Shandong Province is getting bigger every year.