Why did the 98 Yangtze River Dam burst?

During the 1998 catastrophic flood, the strong Yangtze River dam burst its banks. The consequence of the dam breaking is that floods roll south and the middle and lower reaches of the Yangtze River suffer severe floods. This catastrophic flood disaster has affected 29 provinces and cities in China to varying degrees, with the affected area of 3/kloc-0.80 million mu, the affected area of/kloc-0.96 million mu, the affected population of 223 million people and the economic loss of/kloc-0.66 billion yuan.

? (The picture shows: breach)

There are many reasons for the 1998 catastrophic flood, among which Jiujiang dam break is one of the reasons. Jiujiang dam burst for several reasons:

First, the rainstorm is concentrated, and the continuous bad weather has affected it. Since June 1998, the rainstorm has lasted for one month, and the water levels of Poyang Lake and Dongting Lake have risen sharply, beginning to exceed the warning water level. Since June, there have been three consecutive large-scale rainfalls in the Yangtze River Basin. Around July, the flood volume monitored by hydrological stations increased sharply. The flood volume monitored by Yichang Hydrological Station is121500 million cubic meters, and the data monitored by Hankou Station is164.8 billion cubic meters. The hydrological data of Hankou Station exceeds195412 billion cubic meters.

From 65438 to 0954, the Yangtze River stored more than 40 billion cubic meters of flood water. 1998, the flood storage capacity is only 10 billion cubic meters, and the effective flood storage capacity is 5 billion cubic meters. 1998' s catastrophic flood was about1000 billion cubic meters. The Yangtze River could not hold so much flood storage, which led to flooding, and the flood control capacity of dams along the river was tight.

(The picture shows: soldiers fighting floods and rescues)

Second, natural flood storage, the regulation function of rivers and lakes weakened the formation of the Yangtze River flood disaster, which was caused by the long-term destruction of vegetation in the upper reaches. After the founding of People's Republic of China (PRC), with the population growth, the virgin forests and vegetation in the upper reaches of the Yangtze River have been seriously damaged, and deforestation has been frequent. In addition, a large number of lakes in the middle and lower reaches of the Yangtze River have been reclaimed, the function of water storage and regulation of lakes has lost, and a large number of floodplains have been occupied. The third is the construction of some water conservancy facilities. Unreasonable water conservancy projects destroyed the natural ecological function of rivers and aggravated the flood disaster.

Thirdly, the topography of the dam, Jiujiang Dam has a special topography. Jiujiang has a special geographical position. After the Yangtze River entered the Jiujiang section, it entered the mode of "river on the ground". Jiujiang has a high terrain, which is much higher than the surrounding towns when it is dammed. This terrain is similar to the Yellow River. After the flood, the dam could not resist the impact of the flood, and finally overflowed the levee and washed away the town. A large number of garrison officers and soldiers were urgently dispatched to reinforce dams and fight floods day and night.

At noon on August 7, although the officers and men were ready, the danger came. A patrol soldier found that muddy mud was pouring out of the dam and cracks appeared at the bottom of the dam. After this situation was reported immediately, the soldiers put sandbags and their quilts under the lake to prevent water leakage.

However, as soon as the leak was blocked, a large stream of water gushed out from the other side, and the water rushed bigger and bigger, which the soldiers could not resist. Subsequently, vehicles and ships were urgently transferred to block this gap, and several tons and dozens of tons of trucks could not block this gap. Later, a 1600-ton cargo ship was urgently mobilized to sink to the bottom of the lake, and the gap was barely blocked.

(Pictured: Floods flood into Jiujiang City)

Fourthly, human factors, the problem of dam building, Jiujiang levee burst, and it took five days and five nights for the military and civilians to repair this breach and block the flood. In addition to natural factors, human factors are also one of the important reasons for the breach of Jiujiang levee. The dyke with an investment of10 million yuan in Hukou County, Jiujiang is newly built, but it can't resist the flood. As a newly-built levee, its flood resistance is far less than expected.

Under the idea of paying attention to speed and catching up with development at that time, many projects failed to ensure quality and quantity, and there were some problems in dam design and construction. 1954, the water storage capacity of the Yangtze River can reach 40 billion cubic meters. Why is it less than 1998? In addition to destroying the natural ecology, unreasonable and unscientific water conservancy project construction not only failed to play a role, but also destroyed the adjustment ability of nature.

? ? (The picture shows: blocking the gap)

Engels once said: "We should not be too intoxicated with our human victory over nature. Every time such a victory, nature is retaliating against us. "

1998 The lesson of the catastrophic flood warns us that only by respecting the laws of nature and protecting the ecological balance can human beings keep their homes and avoid retaliation from nature.