Why can't the floods in the Yangtze River basin be discharged into the sea in time?

Because the Qingjiang River, Hanjiang River, Dongting Xiangjiang River and Poyang Lake in the lower reaches of the Three Gorges River flow into the Yangtze River uncontrollably, Anhui and Jiangxi are mountainous and the rivers are narrow. Recently, all these water systems have rained and flowed into the Yangtze River. In particular, the flood in Jiangxi province flooded into the Yangtze River through the mouth of the lake to raise the river surface, which led to the slowdown of the river velocity in Jianghan Plain, and the inflow was greater than the outflow.

The Three Gorges can only regulate the flow in the upper reaches of Yichang, but there is nothing the Three Gorges can do about the Qingjiang River in western Hubei, Xiangjiang River in Dongting and Poyang Lake, which have been raining extensively recently. The flood in Wuhan is mainly caused by the occupation and elevation of the river surface by the downstream flood. Jiangxi is sunny and Wuhan is safe.

Once and for all, the water from Poyang Lake can be introduced into the Pearl River system in Shaoguan through Ganjiang River, and a large reservoir can be built near the watershed between Taojiang River and Zhenjiang River. The reservoir connects Taojiang and Zhenjiang. During the flood season of the Yangtze River, the pumping station pumped Ganjiang water into the Pearl River, and the Pearl River flood pumped Zhenjiang water into the Yangtze River. The second plan is to build a spillway from Hukou to Nanjing, which can be parks, farmland, lakes and highways at ordinary times, and houses are not allowed to be built. During the flood season, when the upstream water level is forewarned, the spillway begins to discharge water, and adopts natural flood discharge without water pump. The disadvantage is that the construction is difficult.

This is a worrying problem.

As our mother river, the Yangtze River is also the largest and longest river in China, which not only gave birth to an extremely splendid civilization in history; For thousands of years, it has also provided extremely rich water resources for Chinese civilization and is an important source of the South-to-North Water Transfer Project. Its thousands of kilometers of rivers are truly golden waterways, connecting the most prosperous economic belt in China.

However, this mother river, which has nurtured Chinese civilization for thousands of years, is constantly bringing us great disasters, especially the flood in 1998, which has become the most unforgettable memory of all China people.

At present, the worsening Yangtze River flood has once again frightened hundreds of millions of compatriots.

As we all know, the direct cause of frequent floods in the Yangtze River is that the Yangtze River floods cannot be discharged into the East China Sea in time, and the continuous collection of rivers is an important reason for the rising water level of the Yangtze River, which seriously threatens people on both sides of the strait.

Then, why can't the Yangtze River flood reach the East China Sea in time? History believes that there are the following reasons:

1, the river drop is too small.

The water level difference in the lower reaches of the Yangtze River is too small, which is the direct cause of repeated flood hazards in the lower reaches of the Yangtze River.

Although the drop of the Yangtze River over 6,300 kilometers is as high as 6,600 meters, with an average drop of 84.4 meters per 100 kilometers, the drop of the upstream over 3,300 kilometers over Yibin is as high as 6,200 meters, which means that the water flow in the middle and lower reaches of the Yangtze River is extremely gentle.

In fact, the dividing line between the middle and lower reaches of the Yangtze River, that is, Hukou County, Jiujiang City, Jiangxi Province, is only 68 meters above sea level, which means that the total drop of the 938-kilometer-long lower reaches of the Yangtze River is only tens of meters!

Such a gentle flow naturally leads to flood deposition and poor flow.

2. There are too few estuaries

Another important factor of poor drainage in the lower reaches of the Yangtze River is that there are too few estuaries.

As we can see from the map of the Yangtze River Basin, the width of the basin near the Yangtze River Estuary is very narrow, which easily leads to severe siltation of the river.

In the 6300-kilometer-long Yangtze River, there are many tributaries such as Minjiang River, Jialing River, Hanjiang River, Xiangjiang River and Ganjiang River, and their water volume superposition effect is extremely terrible.

In fact, the Yellow River and other rivers have the same problem. The Huaihe River doesn't even have an estuary. When all rivers rush to the mainstream, the result of rising water level is self-evident.

In contrast, many rivers such as the Pearl River enter the sea, and it is not easy to have poor drainage.

The precipitation is too concentrated.

When the third brother died, many people proposed to cut off the Yarlung Zangbo River in order to defeat the enemy without fighting.

But the problem is that the water quantity of Ganges, especially in flood season, mainly comes from precipitation supply, and the meltwater from upstream is very small for the total runoff.

The same is true of the Yangtze River. Frequent floods in the middle and lower reaches of the Yangtze River are rooted in the influence of climate.

Due to the seasonal movement of frontal cyclones in eastern China, a large-scale precipitation weather, that is, the rainy season, will form in the Yangtze River basin from mid-June to mid-July every year. With the slow movement of frontal cyclone, tributaries in the middle and lower reaches of the Yangtze River will usher in flood season one after another, and the Yangtze River will also form concentrated flood disasters in July and August every year.

4, man-made damage is too serious

In addition to a series of natural factors, the most fundamental reason for the increasingly serious flood disaster in the middle and lower reaches of the Yangtze River lies in human factors.

The development of the western region has not only brought economic development to the vast western region, but also damaged the ecological environment in the western region to varying degrees. The western region is the source of most rivers in China, which first led to the aggravation of soil erosion.

The direct result of soil erosion in the Yangtze River basin is a great increase in sediment concentration in the Yangtze River. However, when the downstream water flow is extremely gentle, a large amount of sediment deposition will inevitably lead to the continuous elevation of the riverbed and the sudden decrease of the capacity of the rivers and lakes.

In addition, with the development of economy, the development intensity of the Yangtze River basin is getting stronger and stronger, and the phenomenon of filling lakes for farmland is becoming more and more common, which makes the flood discharge lakes in the Yangtze River basin less and less. When the flood peak comes, the water level will inevitably rise continuously.

The construction of water conservancy facilities, such as the Three Gorges, naturally plays a great role in flood regulation and storage, and its social benefits are also very considerable. Moreover, by blocking the sediment in the Yangtze River, the sediment deposition speed in the downstream is greatly slowed down.

However, just like the plight of the Yarlung Zangbo River, the Three Gorges is located in the middle reaches, no matter how severe it is. Even if the flood peak above the middle reaches can be stopped, the Three Gorges is doomed to be powerless to the downstream areas below the Three Gorges, especially the flood disaster caused by continuous precipitation. After all, water can't flow backwards.

Although it is an objective fact that the lower reaches of the Yangtze River are densely populated and the relationship between man and land is extremely tense, if we still don't pay attention to the protection of the ecological environment of the Yangtze River, the floods in the Yangtze River will only become more and more terrible, and the disasters we bear will certainly become more and more terrible.

There are many omissions, please correct me.

The Yangtze River basin is flooded, why can't it be discharged into the sea in time?

Recently, the water level in the main stream of the Yangtze River has soared, which has caused great flood control pressure to the areas along the Yangtze River. Since the flood season, the water level and discharge of the main stream of the Yangtze River have risen rapidly. On July 3rd, the high tide water level in Zhenjiang reached 7 7. 10/0m, which exceeded the warning water level (7.0m) for the first time, and the Datong flow rate was 53,000m/s ... On July 4th, the high tide water level rose to 7.34m, and the Datong flow rate reached 58,300m/s..

Simply put, the water on the Yangtze River is anxious and eager to rush to the sea. Whoever gets in the way will directly drown and then rush into the sea.

Some friends want to ask, why can't the flood of the Yangtze River rush to the sea quickly, which poses a great threat to people's personal and property losses?

I think the main reasons are as follows;

1, the state of the Yangtze River basin is convenient for flood collection. The Yangtze River flows from west to east, absorbing water from Minjiang River, Chishui River, Tuojiang River, Jialing River, Wujiang River, Hanjiang River, Yalong River, Xiangjiang River, Yuanjiang River, Ganjiang River and Qingjiang River. The tributaries in the north-south direction merge into the Yangtze River at the same time. This centralized water supply system is most likely to cause floods.

2. The rainfall in the Yangtze River basin is concentrated, and the flood discharge capacity of the Yangtze River is limited. The upper reaches of the Yangtze River are affected by the southwest monsoon and southeast monsoon, and the rainfall itself is relatively large. The key point is that half of the annual rainfall in the Yangtze River is concentrated in July and August. Such concentrated water collection has caused great pressure on the main stream of the Yangtze River. The dividing point of the upper and middle reaches of the Yangtze River is Yichang, which is only 60 to 100 meters above sea level, and the dividing point of the middle and lower reaches is Wuhu, which is only a dozen meters above sea level. On the main stream of a thousand miles, the water level difference is less than 100 meter, and the natural flood discharge capacity is very limited.

3. The Yangtze River basin is relatively developed with dense population and industry. Since the Song Dynasty, the agricultural development in the Yangtze River basin has been growing. Dongting Lake, which used to be 800 miles, is now almost Dongting Lake, and Wuhan, the original city of thousands of lakes, has also greatly reduced the water area. There is a similar situation in Poyang Lake. These lakes have good flood storage function, but they are all filled as cultivated land. Moreover, in the middle and lower reaches of the Yangtze River, there are the largest urban agglomerations and densely populated areas. It is precisely because of the great wealth along the Yangtze River that people pay special attention to the Yangtze River flood.

4, a large number of maintenance of land reclamation, sediment deposition and other phenomena, so that the flood has no way to go. Frequent human activities not only caused the loss of a large number of lakes and rivers along the Yangtze River, but also developed and hardened more wetlands, and the water area of the Yangtze River decreased too fast. Coupled with the large amount of sediment carried by the upstream, it is easy to accumulate, making the river shallow and narrow. Under the dual effects of natural and man-made disasters, the Yangtze River flood has no choice but to embark on the road from the top of human beings and cities.

5. The water conservancy construction of the tributaries of the Yangtze River lags behind and the flood storage capacity is insufficient. The most direct way to solve the flood problem in the Yangtze River is to build water conservancy facilities. If more reservoirs are built on the main tributaries of the Yangtze River for flood storage, it may greatly alleviate the flow of the main stream of the Yangtze River and greatly improve the safety of the Yangtze River. At the same time, soil and water conservation should be strengthened in the middle and upper reaches of the Yangtze River. After all, sediment deposition is also an important cause of floods.

The Yangtze River is our mother river and our golden waterway. At the same time, the Yangtze River will lose its temper and flood cities and rural areas.

Being kind to the Yangtze River means being kind to yourself.

Recently, the flood disaster in the Yangtze River has been affecting the hearts of the people all over the country. Due to the continuous rainfall in the Yangtze River basin, especially in the middle and lower reaches, the Yangtze River floodNo. 1 in 2020 was formed on July 2, and the water levels in Hubei, Jiangxi, Jiangsu, Anhui and other provinces greatly exceeded the warning water level.

(The flood has flowed backward to Wuhan)

(Not only in Wuhan, the water level at Hukou Station of Poyang Lake is 2 1.8 1 m, and the water level exceeding the warning limit is 2.3 1 m)

(There has also been backflow in Dongting Lake. On July 1 1, Jiangxi Flood Control and Drought Relief Headquarters upgraded the level II emergency response to level I, which was the first time that Jiangxi started the response since 20 10.

The reason why the flood was so fierce was that the Yangtze River basin was hit by continuous heavy rainfall, which led to the continuous surge of the Yangtze River water level.

Let me first introduce you to what is a watershed.

River basin refers to the catchment area of a river, for example, the Yangtze River basin covers an area of 6.5438+0.8 million square kilometers. In this area, all precipitation first flows into the tributaries of the Yangtze River, and then flows into the main channel of the Yangtze River through the tributaries.

(Map of the Yangtze River Basin, all precipitation in this area, except evaporation and collection by animals and plants, will be collected in the main road of the Yangtze River and then discharged into the sea by the Yangtze River)

Under normal circumstances, the Yangtze River trunk line can successfully metabolize all the precipitation in this basin. When there is once-in-a-decade heavy rainfall, once-in-50-year heavy rainfall and once-in-a-century heavy rainfall, the width and depth of the Yangtze River trunk line cannot accommodate too much precipitation.

(Since July, precipitation has mainly concentrated in the Yangtze River basin)

To put it bluntly, the main road of the Yangtze River is a very thick sewer. You usually pour a basin of water into it, and this sewer pipe can easily drain the water.

However, even if this sewer pipe is thick and has strong drainage capacity, the drainage capacity is limited after all. If you pour five pots of water at a time, it will exceed its drainage capacity and the water will overflow.

Therefore, when there is heavy rainfall, a large amount of precipitation flows into the main roads of the Yangtze River, which exceeds the carrying capacity of the Yangtze River, and the river will overflow. This is a flood.

(Yangtze River floods over dams on both sides)

In fact, in nature, flood is very common and a natural phenomenon, but for human beings, it is a natural disaster. Because human civilization and cities are basically built along the river, cities will be flooded when they encounter floods, threatening the safety of human life and property.

Since the founding of the People's Republic of China, the floods in the Yangtze River have been continuously controlled, especially after the completion of the Three Gorges Dam, the probability of flooding in the whole Yangtze River has been greatly reduced, because the Three Gorges Project can minimize the flood peaks from the middle and upper reaches of the Yangtze River.

However, this time, the heavy rainfall was concentrated in the middle and lower reaches of the Yangtze River, which was not within the jurisdiction of the Three Gorges Project, thus forming water supply.

Generally speaking, the flood is caused by too much and too sudden precipitation, and the width and depth of the Yangtze River channel are fixed, so it can't bear too much precipitation, which leads to the flood.

First of all, 2020 is really a troubled year. Since July, floods have occurred frequently in various places, especially in the Yangtze River basin, Sichuan, Chongqing, Hubei, Jiangxi and other places, with continuous rainfall for several days. The warning water level of some rivers or tributaries of the Yangtze River even exceeded the extraordinary flood water level of 1998, especially in Hubei and Jiangxi, which sounded the first-class flood response alarm!

Why can't the water in the Yangtze River basin be discharged into the sea in time? It is because the rain is too heavy, lasts for a long time, and there is too much water. The flood flows into the Yangtze River from the upstream tributaries, but the water flowing to the sea cannot escape the water flowing into the Yangtze River. Moreover, Jiangxi and Hubei are flat, and the speed of the turbulent water from Chongqing, Sichuan will slow down in Hubei. If there is too much water in the upper reaches, the Three Gorges Dam will be opened to discharge water, and everyone in the upper, middle and lower reaches must ensure it.

It takes some time for this river to enter the sea. Since the summer of 2020, heavy rainfall has generally formed in southern China, so there will be problems if so much rainfall wants to flow into the Yangtze River in a short time. Moreover, the terrain in the southern region is complex and the terrain is high and low. In case of heavy rainfall for a long time, rainwater can easily gather in low-lying areas, resulting in water rising.

At the same time, the water flow of the Yangtze River is limited. When the water reaches a certain level, it is likely to overflow the dam and flood the farmland and villages. On July 1 1 day, a levee with a length of 120 meters burst in Poyang County, Jiangxi Province, and hundreds of thousands of acres of farmland were flooded, affecting millions of people.

The two most important lakes in the Yangtze River Basin are Dongting Lake and Poyang Lake, which are located in Hunan and Jiangxi respectively. These two lakes can also handle a certain amount of water to a certain extent, and play a role in regulating the water level in the middle and lower reaches of the Yangtze River. However, this year's rainfall is extremely rapid, and the water level of Poyang Lake has exceeded the warning level, and the water level has exceeded the historical limit 1998.

The total length of the Yangtze River is about 6,280 kilometers, and its main stream flows through Qinghai, Xizang Autonomous Region, Sichuan, Yunnan, Chongqing, Hubei, Hunan, Jiangxi, Anhui, Jiangsu and Shanghai * * *1provincial administrative regions (eight provinces, two cities and one district), covering such a large area that heavy rainfall occurs in many areas.

Because the rainfall exceeds the maximum flow of the Yangtze River. . .

Just like you suddenly pour a big bucket of water into your bathroom sink, the drain pipe of the sink is not thick enough, so there will be a basin of water in the sink. And then slowly flow down.

1. It is still a long way from the mouth of the Yangtze River to the East China Sea.

2. There is a lack of rapid drainage of cascade topography in the downstream.

3. Terrain restriction prevents us from digging canals into the sea from the east.

For example, in earlier years, Shanghai Huangpu River excavated two straight artificial canals, Dazhi River and Chuanyang River, from Yaopudong to the East China Sea. In the flood season, you can directly open the gate and discharge it into the East China Sea without going through the Yangtze River.

The Yangtze River or the Yangtze River. Why can't the flood drain into the sea? There are five reasons: "the river that never returns, the waves are exhausted, and the romantic figures of the ages." The Yangtze River and the Yellow River have nurtured the land of China, benefited the Chinese nation for thousands of years, and made the Chinese nation brilliant today.

The Yangtze River originates from Tanggula, which has the reputation of "the roof of the world", with a total length of more than 6,300 kilometers, ranking third in the world, and flows into the East China Sea on Chongming Island in the east. The Yangtze River was formed in ancient times. After about 200 million years of changes, today's water system structure has been formed. It flows through many provinces, municipalities and autonomous regions in China with a drainage area of 6,543,800 square kilometers. It is one of the most important water components in China, and is known as the "water treasure house".

The Yangtze River has nurtured the Chinese nation, but while promoting the development of the Chinese nation, it has also brought many disasters to Chinese sons and daughters, and even involved countless Chinese sons and daughters in the surging river. Now July is the season when the Yangtze River floods. Especially since the flood season this year, there have been many rounds of heavy rainfall in many places in southern China, which has caused the destruction of houses and deaths in many places in the south, which is very serious. According to the forecast of Jiang Water Resources Commission, in the next two days, the flood monitoring points of the main control stations in the middle and lower reaches of the Yangtze River will enter the forefront of the historical flood peak water level.

The Yangtze River flows eastward into the sea, but the middle and lower reaches of the Yangtze River are flooded every year. Even with the passage of time, the degree of flooding in the Yangtze River has become more serious. Since it flows eastward into the sea, why can't it be discharged into the sea in time when the Yangtze River Basin floods?

1. Rainstorms are concentrated and frequent in summer. The Yangtze River basin belongs to subtropical monsoon climate. Due to the influence of monsoon, the water carried from the eastern ocean is very rich and the precipitation is very large.

Declining from southeast to northwest. The Yangtze River basin belongs to the subtropical monsoon climate zone, with strong monsoon, high temperature and rainy summer, and the influence of continental air mass, the southern part of China is prone to heavy rain in summer.

According to relevant statistics, the average annual precipitation in the Yangtze River basin can be as high as 1 100 mm, and the summer precipitation is 85% of the annual precipitation in the war zone, but the precipitation in different areas of the Yangtze River basin is different. Heavy rainfall and many complicated branches flowed into the Yangtze River from different places after the rainstorm, which caused the water level of the Yangtze River to rise rapidly. However, the length of the Yangtze River ranks third in the world, and it takes a long way for the river to flow into the sea.

Second, the vegetation in the middle and upper reaches is seriously damaged, and the river sediment concentration is high. The upper reaches of the Yangtze River mainly flow through plateaus and mountains, and the elevation of the first step in China is about 3,500-5,000 meters.

The terrain is steep and steep, and the water is fast. The source of the Yangtze River is located in the Qinghai-Tibet Plateau, with high altitude, low temperature and extremely fragile ecological environment. However, due to the weak soil layer, landslides or heavy rains in summer are likely to directly wash the slope soil into the river, resulting in high sediment concentration in the Yangtze River. The ecological environment in the upper reaches is fragile, the terrain is steep, and the soil layer is thin. In recent years, it has been destroyed, the ecological environment has deteriorated, and more sediment has been brought into the river by rain.

Third, the middle and lower reaches are flat and silted. The lower reaches of the Yangtze River are dominated by hills or plains with low and flat terrain. Because the Yangtze River is high in the east and low in the west, there is a big gap. The upper reaches of the Yangtze River can be described as "the rock hangs blue and the wall is broken, and the dangerous land flows long", and the current speed can be described as "a thousand miles back to Jiangling in one day"; The downstream terrain is "the mountains are flat and primitive, and the river winds in the wilderness", which shows that the water velocity difference between the upper and lower reaches of the Yangtze River is very large.

The difference in water velocity caused by different topography makes most of the sediment carried by the upper reaches of the Yangtze River settle in the lower reaches, which leads to the elevation of the riverbed and river bottom in the lower reaches, which in turn leads to the flood disaster caused by the river overflowing the embankment. The accumulation of sediment in the downstream will further slow down the speed of river flow, thus causing a vicious circle of flood disasters in the downstream.

Fourth, the storage capacity of lakes has declined. In fact, there are many lakes in the middle and lower reaches of the Yangtze River, among which Dongting Lake and Poyang Lake have great influence on them. As an important water resource, a lake can not only meet the functions of industrial water, agricultural water and domestic water for nearby residents, but also regulate and store rivers, and its area is directly proportional to the storage capacity.

However, with the development of economy, the main lakes in the Yangtze River basin have been seriously damaged, especially Poyang Lake in the lower reaches of the Yangtze River. Due to the development of economic projects such as reclamation and the accumulation of sediment, the area of Poyang Lake is shrinking at an alarming rate. Poyang Lake connects five rivers with the Yangtze River and is an important "transit station" for five rivers to enter the river. However, due to the shrinking area, its water storage capacity is greatly weakened, and its regulation effect on the Yangtze River is getting weaker and weaker.

Verb (abbreviation for verb) The estuary narrows and the Yangtze River flows into the East China Sea on Chongming Island. Due to the topography of the island, the estuary is not large, and a large amount of sediment carried by the upstream accumulates in the estuary, which makes the width of the estuary shrink continuously.

To sum up, although the Yangtze River has a mouth to the sea, with the development of social economy, the ecological environment has been seriously damaged, and the contradiction between economic development and ecological environment protection is prominent, resulting in more and more floods in the middle and lower reaches of the Yangtze River. If human beings take it from nature, they should respect it and pay more attention to the protection of nature while developing economy. We can't just ask nature for survival materials without giving back, and nature will also teach mankind a lesson.

Therefore, protecting the ecological environment is everyone's responsibility. We should work together to build an ecological environment where man and nature live in harmony.

The Hubei section of the Yangtze River basin is flat and prone to water accumulation, and the flood did not reach Shanghai in time through the lower reaches of the Yangtze River. There are repairs every year in history, and there are leaks every year. Can you dig a seasonal river to the north and build a water storage lake 20 kilometers east of the middle route of South-to-North Water Transfer Project, passing through Xinyang, Zhumadian, Zhoukou, Kaifeng, Anyang, Handan, Xingtai, Shijiazhuang, Baoding and Beijing in Henan? More than 50 rivers are connected in series along the way, so that the water can naturally flow eastward. The canal should be wide and deep, and it can also be used for tourism and shipping. The flow should be large, and the excess Yangtze River water should be stored in the water-deficient Central Plains and North China.