Where have the floods been worst this year?

2020 has been a year of great disasters. At the beginning of the year, the new crown epidemic caused panic, and it has continued until now.

In the middle of the year, before the epidemic dissipated, the flood in the south struck suddenly. Why there are so many natural disasters has to be thought-provoking.

A once-in-a-year flood.

This year's floods have been ferocious.

According to the latest news released on June 13, the flood has now spread to 24 provinces (autonomous regions and municipalities). The total number of people affected by the disaster has reached 10,000. The floods also left 63 people dead and missing. More than 7,000 houses collapsed.

In order to resist the floods, 10,000 people were evacuated and resettled.

Floods have been brewing since June 2. On the 9th of the 2nd, the cumulative rainfall in central and northern Guangxi, the central and southern coastal areas of Guangdong, the southern part of Guizhou, the central and eastern parts of Hunan, the central and northern parts of Jiangxi, the southern part of Anhui, the western part of Zhejiang, and the northwestern part of Fujian reached 100,300 mm. <>

There is no problem with the calf at all. It was like a hole in the sky, and the rain slanted down and collected in the river, causing the rivers to flood in many parts of the country.

1. According to the monitoring of the water conservancy department, a total of 110 rivers in eight provinces (autonomous regions), including Guangxi, Guangdong, Fujian, Zhejiang, Jiangxi, Hunan, Guizhou, and Yunnan, have flooded above the warning level.

In Guilin, from June 7 to 8, 16 rivers and 22 stations experienced super-alert flooding. Among them, several river stations reported that this flood is once in 20 years. At the Pingle Hydrological Station on the Guijiang River, the peak water level at 1 o'clock on June 8 was the second largest flood actually measured since the station was established in 1936.

At the Maling Hydrological Station, a tributary of the Li River, the largest flood in 50 years. Not only Guilin, but also the Zengjiang River in Guangzhou has also seen a flood peak once in 20 years, and the highest water level is even beyond the warning water level. <>

Second, the flood not only came fiercely, but this time it was not left.

The Jiangsu Provincial Department of Water Resources issued a blue warning for flooding in the Qinhuai River at 10:40 on June 16, 2020. **The Meteorological Observatory continues to issue a yellow warning for heavy rain on the 17th. From the southwest to the Jianghuai area, heavy rain will continue.

The flood is coming, like a great enemy. Although there have been no large-scale reports of flooding this year due to widespread concern about the pandemic, the damage caused by the floods will not be reduced. <>

3. You must know that such a big flood will not just come to go through the motions.

If you look at the overall destructive power, this year's floods have surpassed those of the past few years. As of June 13, the floods had washed away more than 7,000 houses, causing direct economic losses of 100 million yuan.

And as precipitation and flooding continue, there is a possibility that it will continue to rise.

For example, in Hubei, Hunan, where there are many inland lakes, and Chongqing, where there are many mountains, the disasters caused by lake irrigation and landslides caused by heavy rainfall are very serious.

The severe flooding in She County in Huangshan City, Anhui Province, caused college entrance examination candidates to be unable to take the Chinese and mathematics exams on time.

In Hubei, water levels in Poyang Lake have reached record highs due to continuous rainfall, and many southern provinces, such as Jiangxi, have also suffered from flooding.

Jiangxi was the hardest hit by flooding, and the water level of Poyang Lake has exceeded the standard, inundating many places.

Sichuan, Chongqing, and some areas in Hunan have been seriously affected, and this year there is a lot of rain, a wide range, concentrated rainwater, and untimely discharge, which is easy to cause flooding.

The most serious is Hubei, where heavy rainfall has caused floods of varying degrees to Zhejiang, Jiangxi, Hubei, Hunan, Guangdong, Guangxi, Sichuan, Chongqing, Guizhou and other provinces and municipalities.

This year's waterlogging in Guizhou Zunyi, Guangxi Rongshui, Jiangxi and other places are more serious, heavy rainfall has caused many places across the country to be affected, and everyone is also reminded not to go out during heavy rains.

This year, the southern region has been hit by floods. For example, Anhui, Shanghai, Jiangsu and other places have continued to rain.

<> "Causes of Flood Disasters.

In the natural conditions, large-scale continuous and high-intensity rainfall is the root cause of flood disasters, and the increasingly serious non-climatic factors such as forest vegetation destruction, soil erosion, river siltation, lake shrinkage, collapse, landslide, and debris flow activities also exacerbate the formation and development of flood disasters. We must protect the natural ecological environment, strengthen soil and water conservation, reduce the possibility of flood disasters, and minimize the losses caused by flood disasters as much as possible.

The main reasons for the increasingly serious flood disasters in China are: uneven distribution of rainfall and abnormal aggravation of climate; The middle and lower reaches of the main rivers have a gentle terrain, tortuous river channels, and poor flood drainage; Soil erosion and landslides are intense; The siltation of rivers and lakes is serious, and the flood storage capacity is reduced; The engineering conditions along the major rivers are complex, and the hidden dangers of the embankments are severe.

From the perspective of the occurrence mechanism of flood disasters, floods have obvious seasonal seasonality, regional and repeatability. Floods are not only harmful to society, but can even seriously harm adjacent river basins and cause changes in water systems. In addition, flooding can occur in different areas, including mountainous areas, coastal areas, river estuaries and estuaries, middle and lower reaches of rivers, and areas around glaciers.

Floods not only directly cause loss of people and property, but also cause a series of other disasters such as landslides, mudslides, and epidemics. The main rain-waterlogging area is distributed in the east of Daxing'an Mountains-Taihang Mountain-Wuling Mountain, and this area is divided into four multi-occurrence areas by Nanling, Dabie Mountain-Qinling and Yinshan. There is little rain in western China, and only Sichuan is the area where rain and flooding return to Tantan are common.

There are two conditions that must be met for the formation of a disaster: natural conditions and socio-economic conditions.

1. Natural conditions:Floods are the direct cause of flood disasters. Disasters can only occur when the intensity of natural variation in floods reaches a certain standard. The main influencing factors are geographical location, climatic conditions and topography.

2. Socio-economic conditions:Floods can only be a disaster if they occur in a place where there is human activity. The areas most threatened by flooding tend to be in the middle and lower reaches of rivers, which are often economically developed due to their abundant water sources and flat land.

The threat of flood disasters will restrict social and economic development and affect the safety of people's lives and property.

Floods can be classified as river floods, lake floods, storm surge floods, etc. Among them, river floods are divided into the following types according to their causes:

1. Heavy rain flood: It is the most common and threatening flood. It is formed by heavy rainfall, also known as rainstorm.

2. Flash flood: It is a flood that swells and falls sharply in mountain streams and ravines after heavy rainfall. Mountain floods have the characteristics of suddenness, concentrated rainfall, and strong destructive power, and are often accompanied by disasters such as debris flows, landslides, and landslides.

3. Snowmelt floods: mainly occur in high-latitude snow-covered areas or alpine snow-covered areas.

4. Ice floods: often occur in northern rivers such as the Yellow River and the Songhua River. Because a certain section of the river flows from low latitude to high latitude, when the temperature rises, the upstream of the low latitude section thaws first, while the high latitude is still frozen, and the upstream water and ice accumulate on the downstream riverbed, forming an ice dam and causing flooding. In addition, ice flooding can occur when rivers freeze.

5. Dam failure flood: It is a flood caused by the sudden burst or collapse of a dam or reservoir.

In addition, waterlogging is divided into waterlogging and "door-to-door waterlogging". Waterlogging refers to the formation of waterlogging when excessive precipitation is not discharged from the river in time.

The high-incidence areas of flood disasters in China are concentrated in the southeast of Guangxi, the coastal areas of Guangdong, the coastal areas of Hainan and Zhejiang, the junction of Zhejiang, Jiangxi and Anhui, Liaoning and Sichuan, and the frequency of flood disasters is as high as more than 50%.

Cities that are vulnerable to floods in China are mainly distributed in the middle and lower reaches of the seven major rivers and plains, and Haikou, Nanning, Guangzhou, Nanchang, Wuhan, Changsha, Hangzhou, Nanjing, Beijing, Shijiazhuang, Changchun, Shenyang and other places are more prone to flood disasters.

The causes of flood disasters in China

There is a lot of rain in the summer. There is more rain in cities than in rural areas. The "rain island effect" in cities (high urban temperatures, updrafts, and rainfall) is 5 to 10 percent higher in urban areas than in rural areas.

The urban surface cover is mostly an aquifer and impervious to water. When there is a lot of rain, it can't be drained.

Although there are sewers, "foreign sewers can run cars", and our sewers can only hide rats. 21st century on the ground, 50s of the last century underground. Urban planning and construction is heavy on the ground, heavy on what can be seen, heavy on face, light underground, light foundation, light foundation.

The city is low-lying and prone to intrusion by external floods. Cities are often built on flat terrain, resulting in a large amount of external water and natural drainage is not easy. The city's ability to prevent and respond to disasters is insufficient, and the mechanical drainage capacity is insufficient.

Flood disasters occur due to the following reasons:

1. Soil and geology. The local soil layer is heavy in texture, poor in permeability, weak in vertical infiltration, high in soil organic matter content and large in water storage.

2. Geomorphological features. When the area is located, there are low mountains and hilly areas with undulating surfaces, vertical and horizontal valleys, complex terrain, and slow drainage, etc., which are affected by flood support and backflow, so that the internal water cannot be excluded.

3. Climatic reasons. Due to the uneven spatial and temporal distribution of water resources, it causes short-duration high-intensity rainstorms or long-term continuous precipitation due to the influence of northbound typhoons.

4. Intensity of human activities. In some areas, due to the excessive concentration of human beings, people do not hesitate to seriously damage the ecological environment in order to survive.

5. The flood control project is not up to standard. Due to the disrepair of some flood control projects, when the river overflows, it cannot effectively remove the internal water in time.

Floods can cause great damage to the environment on which human beings depend. For example, floods will cause soil erosion every year, a large amount of soil and its nutrients are lost, resulting in poor land, and at the same time, the sediment content in the water flow increases, resulting in the attenuation of river function, the shrinkage of lakes, and the desertification of cultivated land, and the serious consequences are incalculable.

Major floods will cause a large amount of farmland to be washed away and submerged, crop production will be reduced or even lost, and the agricultural product processing industry and light industry will lack raw materials or the cost of raw materials will increase, resulting in factory production reduction and shutdown, followed by unemployment of workers.

Major flood disasters will also cause the living standards of the people in the disaster areas to decline, lack basic livelihood guarantees, and a large number of victims will appear, disrupting normal social order and impacting all aspects of society.

Heavy to heavy rain occurred in the eastern part of southwest China, southern China, Jiangnan, Zhejiang, and Fujian coastal areas. The continuous heavy rainfall has caused some main streams and tributaries of the Yangtze River, Pearl River, Xijiang River, Minjiang River and other river basins to flood beyond the warning water level. At present, more than 38 million people have been affected by heavy rains and floods, more than 200 people have died or gone missing, more than 120,000 houses have collapsed, and direct economic losses of 26 billion yuan have been lost.

Floods mainly occur in the southern and eastern parts of China.

Floods are natural disasters that occur frequently and cause severe damage.

It mostly occurs in summer and autumn when precipitation is relatively concentrated, and is one of the frequent disasters in the eastern plain of China, and the southern region.

Most severe. Flood disasters include flood disasters and rain and flood disasters. Among them, the disasters caused by heavy rainfall, melting of ice and snow, ice cubes, Qiliang dam failure, storm surge and other reasons caused by the increase of water volume in rivers, lakes and coastal areas, the flooding of water level and flash floods are called flood disasters; Disasters caused by heavy rain, heavy rain or long-term rainfall that produce a large amount of stagnant water and runoff, and the drainage is not timely, resulting in waterlogging, flooding, etc., and the land and houses are flooded.

Worldwide, areas prone to typhoons and rains are also prone to flooding. These areas include: northern Bangladesh and coastal areas; southeast coast of China; Japan and Southeast Asian countries; Caribbean and the eastern coastal region of the United States.

In addition, in some countries, large inland rivers and river basins are also prone to flooding. In China, this kind of disaster is mainly concentrated in the east of Daxinganling-Taihang Mountain-Wuling Mountain, and this area is divided into four multi-occurrence areas by Nanling, Dabie Mountain-Qinling and Yinshan. On the contrary, in the western part of China, there is very little precipitation, and in the entire four regions, only Sichuan is the rain-flooded area.

According to historical statistics, the most flooded areas in China are the southeast coastal areas, the Hunan and Jiangxi regions and the Huaihe River Basin. The sub-flood areas are in the middle and lower reaches of the Yangtze River, Nanling, Wuyishan area, Haihe River and the lower reaches of the Yellow River, Sichuan Basin, Liaohe River, Songhua River and other areas. The regions with the least rainfall and flooding in the country are the Northwest, Inner Mongolia and the Qinghai-Tibet Plateau, followed by the Loess Plateau, the Yunnan-Guizhou Plateau and the Northeast Region. Generally speaking, the distribution of floods in China is characterized by more in the east and less in the west. More along the coast and less inland; There are many plain lake areas, and few plateaus and mountains.