Where will the floods in Henan go?

Where will the floods in Henan Province flow?

Where will the floods in Henan Province flow? As of 8:00 on July 22, 66 large and medium-sized reservoirs in Henan Province have exceeded the flood limit water level. Affected by heavy rainfall, 11 rivers, including the Huaihe River, experienced floods exceeding warning levels. Where will the floods in Henan go? Will it cause disasters to downstream areas? Where will the floods in Henan go? 1

Heavy rains hit Henan. As of 4:00 on the 22nd, 3.004 million people were affected in the province. 33 people died and 8 were missing due to the disaster. 376,000 people were evacuated for emergency evacuation.

As of 8:00 on July 22, 66 large and medium-sized reservoirs in Henan Province have exceeded the flood limit water level, including Zhaopingtai, Yahekou, Zhaowan, Xiaonanhai, Wuyue, Shimantan, Hekou Village, etc. Flood discharge from many large and medium-sized reservoirs.

Where will the floods in Henan go? Will it cause disasters to downstream areas? Water conservancy experts told reporters that most of the floods in Henan will flow into the Huaihe River Basin, and flood control preparations in the downstream Anhui Province are very important.

The Ministry of Water Resources announced on the evening of July 22 that due to heavy rainfall, 11 rivers, including the Huaihe River, experienced floods above warning levels, and some small and medium-sized rivers experienced over-safety and historical floods.

Most of the floods will flow into the Huaihe River Basin

News from the Henan Provincial Department of Water Resources shows that from July 16 to 20 at 8:00, the average flood in Henan Province Rainfall has reached 86mm. Among them, from 8:00 on the 19th to 9:00 on the 20th, moderate to heavy rains, local heavy rains, heavy rainstorms, and extremely heavy rains fell across the province except Shangqiu and Puyang City. There were 48 stations with rainfall exceeding 300mm, and 207 stations with rainfall exceeding 200mm. There are 765 stations with rainfall exceeding 100mm.

The Henan Provincial Hydrology and Water Resources Bureau announced on July 22 that as of 8:00 on the 22nd, 66 large and medium-sized reservoirs in Henan Province had exceeded the flood limit water level, accounting for 10% of the province's flood reporting tasks. Half of the total 132 large and medium-sized reservoirs (excluding Xiaolangdi, Sanmenxia, ??Guxian, and Xixiayuan reservoirs). Large and medium-sized reservoirs such as Zhaopingtai, Yahekou, Zhaowan, Xiaonanhai, Wuyue, Shimantan, and Hekou Village discharged floods in an orderly manner.

Affected by rainfall, the Weihe River, Shuangjie River, Jialu River, Shaying River, Hongru River, Baihe River and its tributary Huangya River experienced rising water levels, and the Weihe River Station exceeded the warning water level.

On July 21, some media reported that 47 reservoirs were releasing floods due to the heavy rain, and urban drainage was also in progress.

So, where will the floods in Henan flow?

Fu Xudong pointed out that generally speaking, urban floods flow mainly through the urban drainage pipe network, which can collect water in urban areas and discharge it to nearby natural water bodies through certain paths, and then flow along the river channels. Flood water flows away.

Fu Xudong introduced that Henan Province has the Huaihe River Basin and the Yellow River Basin, but the confluence area of ??the Yellow River Basin is relatively small in Henan Province, and both sides of the river channel are relatively high, so most floods cannot flow into the Yellow River but into the Huaihe River. watershed. In addition, a small portion will flow into the Yangtze River tributaries.

Achievements have been made in regulating the Huaihe River, but there are shortcomings in engineering and water conservancy supervision.

Henan Province’s Huaihe River regulation project lasted for decades. In August last year, staff from the Henan Provincial Department of Water Resources The article "Promoting Water Conservancy, Eliminating Water Damage and Keeping the Country Safe" written by Jiang Yuhang, Feng Linsong, Tian Zihong, Yang Huishu, and Yin Yanli systematically sorted out the achievements and shortcomings in regulating the Huaihe River.

The article pointed out that the historical situation of "heavy rains and major disasters, light rains and minor disasters, and no rain and drought" in the Huaihe River Basin in Henan has been changed, and the long-cherished wish of "walking thousands of times is not as good as the two sides of the Huaihe River" has become Reality.

At the same time, the article also pointed out problems and shortcomings. The shortcomings of the project are that the disaster prevention engineering system in the Huaihe River Basin is not yet complete. The control projects for major flood control channels such as the main stream of the Huaihe River, Huainan tributaries and the upper reaches of the Beiru River have not yet been fully completed. The flood storage and flood control capabilities of the basin still need to be improved.

There are 360 ??key and dangerous sections of the main flood control rivers in the basin, and the flood control standards are relatively low.

The article also pointed out that the disaster prevention system and mechanism still need to be improved. At present, the overall coordination mechanism for disaster prevention and reduction in the Huaihe River Basin is not yet complete. Disaster information sharing and resource coordination are insufficient. The mentality of emphasizing disaster relief and neglecting disaster reduction has not yet been fully reversed. The situation of low flood control and drainage standards in some cities and undefended rural areas has not yet been fundamentally eliminated. Changes, the role of social forces and market mechanisms have not been fully exerted, and publicity and education on disaster prevention and reduction are not popular enough.

The level of water conservancy supervision also needs to be improved. The article points out that the idea of ??reconstruction and light management is still relatively common at present, especially for small water conservancy projects with imperfect management mechanisms, irregular operation systems, insufficient maintenance funds, and backward safety supervision and operation management methods.

Eleven rivers including the Huaihe River experienced floods above the warning level

On the evening of July 22, reporters learned from the Ministry of Water Resources that affected by heavy rainfall, including the Huaihe River 11 rivers, including 11 rivers, experienced floods exceeding warning levels, and some small and medium-sized rivers experienced floods exceeding warning levels and exceeding historical levels.

It is expected that in the next three days, rivers such as the Zhangwei River, Ziya River, and Daqing River in the Haihe River Basin, the Yiluo River and Qinhe River in the middle reaches of the Yellow River, and the Hongru River, Shaying River, and Lixia River areas in the Huaihe River Basin will There will be significant water rising, and some rivers in the heavy rain area may experience major flooding.

Historically, there have been many floods in the Huaihe River Basin. Information from the official website of the Henan Provincial Department of Water Resources shows that in July 2007, the Huaihe River suffered a basin-wide flood. From July 1st to 16th, major floods occurred in the trunk and tributaries of the Huaihe River. The Nanwan Reservoir experienced the highest water level in history, the Shishankou Reservoir experienced the largest inflow in history, and the Huaihe Huaibin Station and Honghe Bantai Station exceeded the guaranteed limit for a long time. According to the water level, the Laowangpo flood detention area diverted the flood twice.

According to information on the website of the Huaihe Water Conservancy Commission of the Ministry of Water Resources, in August 2018, heavy to heavy rains fell in the upper and middle reaches of the Huaihe River, and local heavy rains caused more than 4 billion cubic meters of floods to enter Hongze Lake. In order to ensure that floods from the upper reaches of Hongze Lake are safely discharged through Hongze Lake, the Jiangsu Provincial Prevention and Control Office dispatched the Sanhe Gate Project to open the floodgates at 15:00 on August 17 and release the floods at 17:00 on August 19th, and went all out to drain the Huaihe River. flood.

On July 26 last year, the Ministry of Water Resources announced that taking into account factors such as rainfall, water level, flow, and flood volume, the Huaihe River will experience a major basin-wide flood in 2020 (approximately once in 10 years), among which A regional flood occurred above Zhengyangguan. After July 14 of that year, there were three heavy rainfall events in the Huaihe River Basin. The cumulative area rainfall in the basin was 170 mm, 89 mm more than the same period in normal years, ranking second since 1961.

The provincial government requires the deployment and implementation of preventive measures in advance and the repair of flood-damaged facilities

Zhou Jianjun, professor and chief researcher of the Department of Water Conservancy and Hydropower Engineering at Tsinghua University, introduced that Henan floods Most of it flows into the Huaihe River. From a relative position perspective, Henan Province is located in the upper reaches of the Huaihe River Basin, and Anhui Province is located in the lower reaches of the Huaihe River Basin. At the same time, due to the terrain, the water flow from Henan into Anhui is relatively turbulent. Therefore, flood prevention preparations in Anhui Province are very important.

According to Anhui News Network, on the afternoon of July 21, Anhui Province Governor Wang Qingxian presided over the 148th executive meeting of the provincial government, emphasizing that Anhui Province is currently in the critical period of "seven down and eight up" flood prevention, disasters Defense work cannot be relaxed at all. It is necessary to strengthen prevention against typhoons, thunderstorms, local heavy rainfall, etc., especially to strengthen the investigation and rectification of hidden danger points for flood control and drainage in urban areas, and to deploy and implement preventive measures in advance. It is necessary to strengthen assistance and assistance to the affected people and repair water-damaged facilities as soon as possible.

The meeting pointed out that we should further improve the emergency command system, improve the rapid response mechanism for disasters and dangers, strengthen departmental linkage and regional cooperation, effectively carry out rescue and emergency response work, and make every effort to ensure the safety of people's lives and property.

Public information shows that the Wangjiaba Gate located in Funan County, Fuyang City, Anhui Province is the main control project in the Mengwa flood storage area of ??the Huaihe River. The special geographical conditions of the Huaihe River make the Wangjiaba Gate located at the junction of the three rivers extremely significant.

Wangjiaba Gate is also known as the "barometer" of flood control in the Huaihe River and the "weather vane" of the Huaihe River disaster.

Therefore, the situation of Wangjiaba Gate has attracted much attention. There were rumors that Wangjiaba would open floodgates to store floods due to rainfall in Henan.

In this regard, on July 21, the relevant person in charge of the Hydrology and Water Resources Bureau of Fuyang City, Anhui Province stated in an interview with the media that due to the continuous heavy rains in Henan, the water levels in the upper reaches of Wangjiaba on the Huaihe River and Fuyang Gate on the Yinghe River were even. There was a significant increase. At 17:00 on July 21, the water level in Wangjiaba of the Huaihe River was 26.36 meters, 0.36 meters above the established waterproof level, and the water level upstream of the Fuyang Gate of the Yinghe River was 27.78 meters, 0.19 meters higher than 6:00 a.m. However, it has not yet reached the warning level.

According to predictions from the hydrology department, Wangjiaba on the Huaihe River has basically reached the highest water level during this rising water level, and the water level upstream of the Fuyang Gate on the Yinghe River will not exceed the warning level (30.5 meters).

According to Fuyang News Network, central and southern Henan is located upstream of the main river in Fuyang City, which has an impact on river flood control in Fuyang City, but has less impact on the northern part of the city.

On July 20, Fuyang City issued the "Emergency Notice on Effectively Carrying out Safe Flood Control Work" overnight, arranging and deploying Yinghe River flood control dispatch and Huaihe River embankment inspection and inspection work. Funan and Yingshang Counties The *** organized 397 cadres and groups to carry out inspections on rivers that exceeded the water level to ensure safety during floods. Where will the floods in Henan go? 2

In recent years, the frequency of extreme weather events has increased significantly, with extreme high temperatures, floods and droughts occurring in many places at the same time. During the recent period, the western United States has suffered a drought that is particularly rare in 1,200 years. Germany's once-in-a-millennium floods have killed at least hundreds of people, and our Henan province has also experienced the heaviest rainfall on record in the past few days. Xinxiang's rainfall exceeded that of Zhengzhou in just 2 hours. The Ministry of Water Resources and the Meteorological Bureau also issued a meteorological warning for flash flood disasters.

In terms of the main causes of floods, ice floods, flash floods and rainfall floods are relatively more frequent, and have obvious seasonal characteristics. For example, floods in the south often occur when entering the country. After the flood season, that is, from May to October every year, in the north, it is usually during the cold flood season, that is, the winter and spring seasons, that water rises easily due to ice blockage and thawing. But in general, the months with the highest probability of major floods are July and August. The reasons are as follows:

The Yellow River, Haihe River, Yangtze River, Pearl River, Songhua River and Liaohe River, their The flood season covers these two months, and the precipitation during this period is also the largest in the whole year;

As for foreign countries, of course, the same is true. For example, the Nile River will enter the flood season from July to October, and the Amazon will enter the flood season from July to October. The river will enter the flood season from June to July, while the flood season of the Mississippi River in the United States is from February to May every year.

Even if human beings are now in heaven and earth, they still have no way to deal with natural disasters. So, where did the water from the great flood go in the end? Why do dams release water? Let me tell you a real example that happened recently:

A few days ago, two reservoirs in Inner Mongolia burst their banks due to heavy rains. After the dam burst, the floods directly washed away the national highways. Friends who don’t know the situation are shocked. I am asking why the flood was not discharged in advance, but in fact, the Yong'an Reservoir located upstream did not have a flood discharge hole, and the distance between it and the Xinfa Reservoir downstream is only 13 kilometers. The method of regulating the water volume of the reservoir is natural discharge, so , such a large amount of water broke down the dike at once, and finally the flood flowed into the main stream of the Nen River.

In fact, this is what happened. In a short period of time, it rained too much. The original dam body could not withstand so much water, and then the dam collapsed. Floods were formed, and finally the water merged into the main stream. This actually reflects a path of water circulation. All the water on the earth is actually constantly circulating. The water in this place is transferred to another place. It may even change its own state, with small rivers flowing into large rivers, large rivers flowing into the ocean, typhoons forming on the sea surface, and typhoons bringing rainfall, etc.

Large rivers such as the Yangtze River and the Yellow River have large drainage basins and very complex water networks. In addition to naturally formed lakes and river networks, we have also built many reservoirs and artificial rivers and lakes. Mainly for the purpose of more reasonable regulation and storage of water resources. This is because when the short-term rainfall is too large, the tributaries of the rivers will have flood peaks that will flow directly into the main stream. And those river networks with relatively weaker storage capacity are more likely to form flood peaks due to heavy rains, which are uncontrollable. The passing of the flood peak will naturally cause fatal damage to the surrounding things.

When the Three Gorges Dam and other water conservancy projects were built in the past, there were some voices of doubt at the beginning, including the huge cost of construction and the number of displaced people involved. , and some fish animals with migratory characteristics will also be affected by the construction of dams.

But all these questions now have answers. Since the completion of the Three Gorges Dam, it has not only set a world record for the highest annual power generation of a single power station, but also improved more than 600 kilometers of shipping channels. It has played a huge role in drought and flood prevention.

When the Three Gorges Dam was designed, it reserved a flood control storage capacity of 22.15 billion cubic meters. When it encounters the largest flood peak after its completion in 2020, 11 deep flood discharge channels will be opened to release floods. The Three Gorges Dam The flood control capability is very strong. Relevant experts have said that the Three Gorges Dam can control the flow of Zhicheng below 80,000 cubic meters per second during a major flood like the one in 1870. The flood in the Jingjiang River section that occurs once in a century can also be prevented. No flood diversion is achieved through the Three Gorges Dam.

Of course, many people know that the design of the Three Gorges Dam is mainly to retain water from the upper reaches of the Yangtze River, which can effectively solve the flood problem in the main stream of the Yangtze River, but this does not mean that It will have a big impact on the lower reaches of the Yangtze River. As mentioned earlier, the Three Gorges Reservoir has a special flood control storage capacity. Although the Three Gorges Dam will release floods from time to time according to the water volume, this does not mean that the flood will be released as much as desired, because there are also standards for downstream flood control compensation, and the flood will be released according to the standards. The downstream areas will not be allowed to increase their own flood control pressure.

Moreover, for the downstream, problems may really arise if the flood is not discharged as required. Even though the dams are made of hard materials such as concrete, these buildings also have the ability to withstand floods in the face of floods. The dam has limited bearing capacity. When the water in the dam exceeds its own load, the dam will easily break. This is a real disaster for the downstream. Therefore, it is necessary to release floods from the dam, whether it is for It's the same for both upstream and downstream.