What are the causes of the floods in the Yellow River in China s history?

The causes of flooding can be divided into two causes: deep and shallow. shallow, flood control measures for tofu residue; Deeply, the environment deteriorates also. And high temperatures, everyone knows that environmental degradation is the root cause.

The main reasons for frequent flood disasters: 1. The amount of water entering the lake is large, and the amount of water leaving the lake is small. The average annual water inflow into the lake is as high as 301.8 billion m3, which is three times that of Poyang Lake, five times that of the Yellow River, and 10 times that of Taihu Lake.

Since there is only one outlet, the flood discharge capacity is limited. In the event of heavy rainfall, the formation of a trend of pressing up and down, resulting in tens of billions of m3 of excess floods stranded in the lake, resulting in flood disasters. 2. Sediment accumulation and shrinking of lake capacity.

A large amount of flood water brought a large amount of sediment and silted up in Dongting Lake, with an average annual siltation of 100 million years, and the average siltation of the whole lake has been high. 3. The flood control standard is low and the disaster resistance is weak. After the first phase of treatment, the flood control standard has been raised from once in 3-5 years to once in 5-10 years.

However, this standard is far from being able to adapt to the severe situation of flood control in the Dongting Lake area, and it is far below the standard of once in 20-100 years that the country's seven major rivers have reached. Although the direct cause of flood disasters is the long-term continuous heavy rain caused by abnormal weather, human factors are also the main cause. Due to the expansion of the population, the competition for land in forests, lakes and rivers, excessive deforestation, destruction of vegetation, filling of lakes, encroachment on rivers and other predatory activities of human beings have caused damage to ecosystems and increased the probability of flooding.

Forest destruction reduces human ability to defend against floods Pooling precipitation data from around the world, scientists have found that many arid regions have become unusually arid in this century due to the increase in the earth's temperature, while flooding has increased significantly in humid regions.

1. Human factors: The Yellow River is the birthplace of Chinese civilization and the cultural, political and economic center of ancient China, so it was developed early. However, due to people's irrational development of the Yellow River Basin, the Yellow River has suffered serious soil erosion, resulting in serious sediment accumulation in the Yellow River

1.The Yellow River flows through China's three major topographic ladders, from the Qinghai-Tibet Plateau in the east to the North China Plain in the westThe lower reaches of the Yellow River are located in the temperate monsoon climate zone, and the rainfall is obviously seasonal, and the rainfall is often too concentrated in the rainy season. Beg.

Reasons: 1. Due to sediment accumulation in the lower reaches of the Yellow River, the riverbed is raised, forming an above-ground river, and the low-lying terrain on both sides of the river embankment is prone to flood disasters.

2. The lower reaches of the Yellow River are located in the temperate monsoon climate zone, and the precipitation is concentrated in summer, with heavy rainfall.

Treatment measures: 1. Strengthen the embankment and dredge the river.

2. Construct reservoirs in the upper and middle reaches to regulate river runoff.

3. Plant trees and grasses in the middle reaches to prevent and control soil erosion and reduce the sediment content of rivers.

4. Strengthen the construction of flood discharge areas downstream.

The middle reaches of the Yellow River may have a major floodBecause of the continuous rain for several days.

According to the analysis, the Yellow River Basin is in the northern rainy area during the flood season this year, and the rainfall in the Shanxi-Shanxi region, the Sanhua interval and the lower reaches is about 2 percent more than the same period in normal years, and the rainfall in some areas in the middle reaches is 2 5 percent more than that in the same period of the normal year, and large floods may occur in the middle reaches of the Yellow River.

The Ministry of Water Resources held a meeting on the study and deployment of key flood prevention work in the middle reaches of the Yellow River, stressing that the meteorological and hydrological situation in the Yellow River basin is complex, the flood control engineering system is not perfect, there are weak links in silt dams, it is difficult to prevent floods and mountain floods in small and medium-sized rivers, and cadres and people lack practical experience in flood fighting. At present, the Yellow River has entered a critical period of flood prevention, and doing a good job in preventing flood and drought disasters is a particularly arduous task and a particularly heavy responsibility.

The meeting stressed that in the face of the complex flood control situation of the Yellow River, we should proceed from the most unfavorable situation, work in the best direction, resolutely avoid the occurrence of major personnel incidents, resolutely avoid the failure of flood control projects within the standard, resolutely ensure the safety of important national infrastructure, and resolutely ensure the safety of key tasks of economic and social development.

During the critical period of flood control, Zhenjiang and Runzhou took multiple measures to do a good job in flood control

Recently, the Yangtze River basin has also entered a flood-prone period (from late July to early August), and flood prevention work in various localities has also reached a critical period. Zhenjiang has been experiencing continuous precipitation for several days, and in view of the possible situation, the Zhenjiang Runzhou water conservancy department has taken swift action to go deep into the front line of flood control to investigate dangerous situations and hidden dangers.

In order to do a good job in flood prevention this year, the Water Conservancy Bureau of Runzhou District has taken multiple measures to improve the flood control capacity of the Yangtze River embankment in Runzhou District, and weave a dense flood control guarantee "safety net". "From the bidding to the advent of the main flood season, there are only 6 months, in order to speed up the progress of the project, we are also moving the party history learning and education classroom to the front line of the project, encouraging party members and cadres to charge ahead, coordinate contradictions, seize the construction period, and finally effectively guarantee the orderly progress of the main project. ”

Dong Chunyong, director of the Runzhou Water Conservancy Engineering Management Institute, said. "At present, the flood control situation in the upper reaches of the Yangtze River is still very severe, and it is unknown whether there will be extreme weather in the future, and the pressure on flood control and flood control is still very great. We will never slack off in the slightest, and will continue to go all out and be ready to ensure the safety of the people in the city.

Xia Xingzheng, director of the Runzhou District Water Conservancy Bureau, said.

The above content refers to the Zhongqingwang The middle reaches of the Yellow River may have a large flood.

The reason why the middle reaches of the Yellow River may have a large flood is that the Yellow River basin is in the northern rainy area during the flood season this year, and the rainfall in the Shanxi-Shanxi area, Sanhua area and the lower reaches is about 2 percent more than that in the same period of the normal year, and the rainfall in some areas in the middle reaches is 2 5 percent more than that in the same period of the normal year, and a large flood may occur in the middle reaches of the Yellow River.

Floods in the Yellow River Basin are mainly divided into two categories: rainstorm floods and ice floods. Ice floods occurred in the lower reaches of the Yellow River in January and February. Ningxia, Inner Mongolia river section mostly occurs at the end of March, the ice thaw and the flood of the river flows to the downstream of the peach blossom to open it, so it is called Taoxun rainstorm flood occurs in July and August, and occurs in September and October called Qiuxun, the two are connected in time, and it is customary to call Fuqiu Daxun.

The Fuqiu Flood is the main flood period in the Yellow River Basin, and most of the flood disasters in history occurred during this period, and the threat to the downstream is the most serious.

The middle reaches of the Yellow River are very bent, the originally straight river water has to bend in the middle reaches, the flow speed increases, the middle reaches of the river have frequent precipitation in summer, and the tributaries flood and then flow into the Yellow River, and the terrain in the middle reaches is flat.

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Analysis: Soil erosion in the upper reaches of the river, carrying a large amount of sediment. Downstream, the river widens, the water flows slower, the sediment begins to deposit, the riverbed rises, and the levees become relatively low, so it floods.

Pay attention to a few details.

1. The downstream river channel is wide, and the same water flow, the wider the river channel, the slower the water flow will inevitably be;

2. The proportion of the carrying volume of the water flow to the change of the flow velocity is geometric. When the flow rate is slow, the amount of sediment carried is more than doubled, so the sedimentation rate is very fast;

3. The Yellow River is known as the "river on the ground". Perennial sediment accumulation, resulting in the riverbed has been higher than the plain height;

4. Let's protect the environment.